Groundwater Modeling Blog

Groundwater Modeling & Robots????

2012-01-30T10:33:00.000-05:00

As some of you know, my wife and I have been coaching our local high school robotics team. The team competes in the FIRST Tech Challenge (see www.usfirst.org). It is a really great way to keep kids interested in science and math. Also, a practical benefit is the $9 million in scholarships available to robotics team members when they apply to college.

Our team is #4433 Smokin' Motors (so named because last year we killed an electric motor in spectacular fashion). Please check out the team web site at www.cwrobotics.org. This is our second year competing in FTC and we have qualified for the Pennsylvania State Championship at the end of February.

There are two reasons I wanted to put this in my blog. First, we live in a very rural part of Pennsylvania where we have lots of cows, horses, and tractors, but not many engineering companies. Our team could really use some mentors who are engineers. I have always been impressed by the diverse background of groundwater modelers and I am confident some of your out there are engineers (or have an interest in robots)! If you would be interested in helping our team, please let me know. I envision several web meetings between September 2012 and January 2013 to introduce you to the challenge for next year, explain our strategy in tackling that challenge, and get some ideas on how we might go about that. We would probably only need about 4 hours of your time over that 5-month period. If you are interested, please send me an email (jrumbaugh@groundwatermodels.com).

The second reason for posting this to my blog is to see if any of you would be interested in starting a robotics team. Teams do not need to be associated with a school and they do not need to be in the USA. A lot of the teams are boy scout troups, girl scout troups, home-school organizations, etc. FTC teams need between 2 and 10 kids ages 14 to 18. The cost of starting a team is about $2,500. That includes purchasing all of the materials and attending one or two competitions. I would like to sponsor one or two teams each year. If you would be interested, please contact me.

My daughter Ingrid and I will be make a brief presentation at the end of my upcoming webinar on February 20. The webinar is free and will be presented at 11 am Eastern Time (USA) and 8 pm Eastern Time. I would just like to take the last 5 minutes or so to describe our team and FTC in general. If you would like to attend, there are links on our main home page at www.groundwatermodels.com.

Thanks!

MODFLOW-NWT Version 1.0.4

2012-01-30T09:21:00.000-05:00

A new version of MODFLOW-NWT (version 1.0.4) was released last week. The new version can be found in Groundwater Vistas Version 6.14 Build 16. It is on our web site now for download.

The new version of MODFLOW-NWT has two changes. The first allows the MNW1 Package to be used with MT3DMS. In previous versions, the MNW1 contribution to the flow-link file was disabled. It is now functional. The second change is for the SFR Package. Previous versions of MODFLOW-NWT did not support the option where NSTRM could be negative (thus signifying unsaturated flow beneath stream channels). That option is now supported.

Happy New Year

2012-01-06T11:26:00.001-05:00

We hope your holidays were great!

We have been busy, as usual, trying to keep Groundwater Vistas up to date. There have been three major things added since my last posts before the holidays. These include (1) tied parameters in Pest, (2) modifications to how Storage pilot points are handled, and (3) a new update for MODFLOW-NWT.

Tied parameters in PEST are those that are modified based on how another parameter changes during calibration. A common example is vertical hydraulic conductivity, which may be set as a multiple of horizontal hydraulic conductivity. PEST would estimate horizontal K and then vertical K is automatically adjusted based on the new horizontal K value. We have had some of this sort of thing in the past with pilot points (see previous posts) but this new feature works with any zone-based or reach-based parameter. Step 1 is to define every parameter you need (including the ones that are tied) under Model|Pest|Parameters. In Step 2, select Model|Pest|Tied Parameters. The parameters on the left side of this spreadsheet are ones from step 1. For those parameters that are tied, enter the parameter they are tied to on the right. Just leave all untied parameters unchanged.

In previous versions of Groundwater Vistas, the storage pilot point represented the primary storage coefficient of a cell. For a type 1 layer using the BCF Package, this would be specific yield. For type 3 layers in BCF or unconfined layers in LPF, where the water table was lower than the layer top, this would also be specific yield. For all other conditions, the pilot point would be the storage coefficient in BCF or specific storage in LPF. We now have two types of storage pilot points in GV6, Storage (or specific Storage) and Specific Yield. When starting a new model in Vistas or opening an older model that did NOT have storage pilot points, the new approach is used. If you open an older model in Vistas that had storage pilot points, GV will default to the older legacy approach so as not to change your model. You can opt for the new approach by selecting Model|Pest|Options - Targets tab.

And finally, a new version of MODFLOW-NWT was released by the USGS on December 29. Some solver issues were fixed and changes were made to the UZF and SFR Packages. Note that there is some additional data input for UZF that we do not yet support. However, your model will still run without these options. If you review these changes on the USGS web site and need these new options for your model, please let me know so I can make it a higher priority.

All of these changes are in Version 6.14 Build 4 which is on our web site now.

Happy New Year!

Jim

Free Webinar in November

2011-10-18T13:54:00.001-04:00

I've added a new free webinar on Thursday, November 10. The topic will be migrating from MODFLOW88/96 to the newer MODFLOW2000, MODFLOW2005, and MODFLOW-NWT. Even though MODFLOW2000 has been out for over a decade, a lot of modelers who grew up with the classic version are reluctant to change. Plus there are a lot of legacy models still using the older versions. This webinar will discuss the things to watch in moving to the new MODFLOW versions, including important new features and packages. Differences between the newer versions will also be described.

The webinar will last about one hour and be presented at 11 am and 8 pm Eastern time (USA) on November 10. You can sign up on our web page at www.groundwatermodels.com. Just look for "Free Webinars" right in the middle of the main page.

Email in Groundwater Vistas

2011-10-12T15:30:00.000-04:00

I just added email notifications in Groundwater Vistas Version 6.08 Build 2. You can set it up so you receive email notifications when a MODFLOW, MODPATH, or MT3D run finishes. The latter also works for the automated sensitivity analysis. You can configure it to send periodic update emails during a Pest or BeoPest run. The latter provides a summary of objective function components at each iteration. It sends a special email when the run is finished.

To use this feature, you first select Model|Notes|Email setup. The first time you start using emails in GV, be sure to click the button at the top of the dialog to configure your email account. You may need help from your IT staff to do this depending on the complexity of your email system. Then activate the model run and pest run options on this dialog. The pest run has an added setting which is the frequency (in minutes) that GV checks the Pest output file.

We will likely have more related options in the coming weeks.

The PEST Trilogy

2011-09-08T09:34:00.000-04:00

Science fiction fans are likely familiar with the trilogies of Tolkien and Asimov. There is now a new trilogy in the science non-fiction category from John Doherty, Randy Hunt, Mike Fienen, and Matt Tonkin. This trilogy describes the use of Pest in highly parameterized inversions and uncertainty analysis. All three are USGS Scientific Investigation Reports and can be downloaded from the following links:

Pilot Points

Using Pest in Model Calibration

Uncertainty

Many of the techniques are available in Groundwater Vistas and I cover these in my Webinar on using Pest with Groundwater Vistas. The next Webinar is in October. Let me know if you are interested.

Quarterly Webinar

2011-06-22T07:35:00.000-04:00

I posted the recording from the June webinar that discussed the status of Groundwater Vistas and a brief summary of the MODFLOW conference. Go to www.groundwatermodels.com to download it from the main page. Based on the good feedback I've been getting from participants, I'm going to expand these free webinars to include a monthly series on various short topics and guest lectures. I am planning a late July session on migrating from MODFLOW96 to MODFLOW2000/2005. I mentioned this briefly in the last webinar and received a lot of interest in such a topic. Look for more information after the July 4th holiday.

MODFLOW-NWT Update

2011-06-03T15:28:00.002-04:00

The USGS released a minor update to MODFLOW-NWT (Version 1.0.1) this week that fixes a problem with the HFB Package and some issues with releasing memory after the run. We have updated our version as well and Groundwater Vistas Version 6.04 Build 8 has this new update. You can download it from our web site.

ESI Quarterly Webinars Start in June

2011-05-26T09:44:00.000-04:00

I presented a free webinar at the end of March on our new software versions. That was very well received so I want to continue offering these free one-hour webinars periodically. The next one has been scheduled for June 16 at 11 am and 8 pm Eastern time in the US. I will talk about the status of our new software versions and highlights from the MODFLOW Conference. You can sign up at groundwatermodels.com - there are links right on the main page.

MODFLOW-USGs

2011-05-20T08:29:00.005-04:00

For those of you attending the MODFLOW Conference at Colorado School of Mines in a couple of weeks, I will be demonstrating the use of nested grids in a new version of MODFLOW called MODFLOW-USGs, developed by Sorab Panday. We use the term nested grid to refer to a refinement to the finite-difference grid where the grid lines do not extend beyond the refined area, as shown above. This greatly reduces the number of grid cells. It is similar in concept to MODFLOW2005-LGR (Local Grid Refinement), except that MODFLOW-USGs is one simulation rather than two. Chris Langevin and Sorab Panday will both be presenting papers on this new style of MODFLOW modeling and on MODFLOW-USGs specifically.

Our demonstration will take place on Monday evening, June 6th, from 5:30 to 7:30 in the Green Center, Friedhoff Hall. Please stop by and I can show you more. I will also be posting a lot more about this new MODFLOW version in coming blog posts.

Hope to see you there.

GV with MODFLOW-NWT on the Web

2011-05-17T21:38:00.002-04:00

Just a quick note that Groundwater Vistas 6.04 Build 1 with MODFLOW-NWT is on our web site! Update installers and the full installers both have this version in 32-bit and 64-bit flavors.

MODFLOW-NWT Source Code Released

2011-05-17T07:28:00.002-04:00

And there was much rejoicing... The MODFLOW-NWT source code is out now (see link below). We will have it hooked up in Groundwater Vistas Version 6.04 Build 1, probably by tomorrow. If you see 6.04 build 1 on our web site (www.groundwatermodels.com - click Clients/Downloads), then you know we have added MODFLOW-NWT.

So now you'll probably want to know how to use it. It's actually pretty easy to get it working because it's essentially MODFLOW2005 with a new solver. So here is what you need to do:

Select Model|MODFLOW|Packages and change the version to MODFlOW2005
You must use the LPF Package (BCF not supported). The easy way to make that happen is to turn on "Automatically Reset Package Units" in step 1.
Select Model|MODFLOW2005|Packages and turn on the checkbox that says "Use Upstream Weighting (UPW) and Newton Solver (NWT) instead of LPF Package"
Select Model|MODFLOW2005|Options and click on the "NWT General" tab. The NWT Solver has lots of options under this tab and the one labeled "NWT Methods". See notes below on the solver settings.

That is all you need to do. The next time you run the model, you will be running MODFLOW-NWT. We do have a windows DLL version, as well as the USGS command line versions in both 32-bit and 64-bit flavors.

Just a note on the solver settings. There are a lot of settings but one thing I really like about the implementation of this NWT solver is the use of an OPTIONS variable that can be SIMPLE, MODERATE, COMPLEX, or SPECIFIED. If you choose one of the first 3 settings you eliminate most of the settings and NWT will configure itself. We are defaulting to MODERATE in Vistas but we'll see how that goes. As we gain more experience we may change that. Anyway, if you choose one of those first three settings then you only need to set the following variables in the solver:

HEADTOL, FLUXTOL, MAXITEROUT, THICKFACT, LINMETH, IPRNWT, and IBOTAV

These variable names are listed on the GV dialog and they are all on that first tab mentioned above.

One other note on MODFLOW-NWT is the specification of dry cell head. We have set up GV so that cells will not show up as dry. This is essentially the same thing that MODFLOW-Surfact does. If you would rather see dry cells, there is a checkbox on Model|MODFLOW2005|Options - LPF Options tab called "IPHDRY". Turn that option on if you want to see dry cells. There is one other option there that is for MODFLOW-NWT which will reduce pumping rates in cells that become desaturated. See the MODFLOW-NWT manual for more information.

We have noticed some lingering "stack overflow" problems with both MODFLOW2005 and MODFLOW-NWT so if your model crashes please send us the GWV file so we can figure out the cause. We have tried to test this on large problems but there is no guarantee that we caught all of the problems. This is a long story - corner me at the MODFLOW conference in a couple of weeks and I'll bore you with it.

Here is the link. It is not live yet on the USGS Groundwater Software page but should be soon.

water.usgs.gov/nrp/gwsoftware/modflow_nwt/ModflowNwt.html

MODFLOW-NWT Documentation Released

2011-05-12T08:09:00.001-04:00

The documentation for the new MODFLOW-NWT code is now on the USGS web site (see link below). This new version of MODFLOW offers a Newton formulation for nonlinear problems, especially those involving drying and rewetting of cells. It is a special version of MODFLOW2005 that has a new solver (NWT) and a new version of the Layer Property Flow (LPF) Package called the Upstream Weighting Package (UPW). The format of the UPW Package is virtually identical to LPF so the transition to MODFLOW-NWT is relatively simple. It's really just a matter of substituting a new solver file.

MODFLOW-NWT handles dry cells in a manner similar to MODFLOW-Surfact's pseudo soil relations. So if you do not want to spend the money for MODFLOW-Surfact, then MODFLOW-NWT is a viable alternative. The downside is that MODFLOW-NWT can be slower than MODFLOW-Surfact. I have confirmed this with some test problems and real models. But it works!

The source code should be available in a few days. As soon as the source code appears on the USGS web site we will activate this feature in Groundwater Vistas Version 6. I will make another post when that happens.

Link to MODFLOW-NWT manual: http://pubs.usgs.gov/tm/tm6a37/

SEAWAT2000 Update Released

2011-05-03T09:16:00.002-04:00

The USGS released an update to SEAWAT2000. The new version is called 4.00.04. The update fixed a problem with the drain observation package and the transport observation package. Apparently there were also reports that the program did not run on Windows 7, although I never had any problems with that. Both 32-bit and 64-bit executable files are provided.

The new version of SEAWAT2000 will show up in Groundwater Vistas Version 6.02 Build 12 later today or tomorrow. If you would like to download SEAWAT2000 from the USGS, use the following link:

seawat2000 download link

Groundwater Vistas Version 6 Status

2011-04-27T10:28:00.002-04:00

I mentioned last week that I would provide a status report on Groundwater Vistas Version 6. This version has a bit more installation complexity than previous versions. Here are some observations from the first month:

If you download the full installations from our web site, make sure to only use the 32-bit installer if you have the Standard version of Groundwater Vistas. Even if you have the 64-bit version of Windows, the Standard version of GV will only work under 32-bit mode.
Also, when downloading from the web, you will see two files called "setup" after unzipping the archive. You need to run the one with a *.exe extension rather than the *.msi file.
When using a security code instead of the HASP key on Windows 7, you will often need to right-click the gwv.exe program file in the gwv6 directory and choose "run as administrator". Then set the security code and close the program. If you do not do that, the security code may need to be entered again the next time you use Groundwater Vistas.

We fixed a few minor problems so far. The latest version is 6.02 Build 10. Here are the modifications:

The MODFLOW+MT3D option on the Model menu was not running MT3D after MODFLOW.
Added direct support for importing MODFLOW-Surfact *.con (binary concentration) files under Props/Import/Matrix. You could import them before but it was not obvious.
Importing data into the SWI interfaces on the props menu (using row-column-layer format), the 4th column of data was being ignored.
There was a problem importing an existing GHB input file using MODFLOW2000 format with reach numbers. This was actually also a problem in version 5, but just showed up now.
Log color floods of concentrations produced strange results when negative concentrations were computed by MT3D. They are now ignored.
MODFLOW2005 was not releasing memory properly after a run. This was actually a bug in the USGS code but it does not affect command-line programs (only our DLL versions).
USGS apparently fixed a previous bug in MODFLOW2005 where the ET cell-by-cell flows from the UZF Package had the wrong sign. We just multiplied by -1 in Vistas but that caused problems with the new version where it was corrected. Everything is fine now between UZF in MODFLOW2005 and in Vistas.

So Far, So Good!

2011-04-20T10:28:00.004-04:00

The roll-out of Groundwater Vistas 6 and AquiferWin32/Winflow Version 4 has gone very well. Thanks to all of the "early adopters" out there! This is always a nervous time for us when a new version is released but these have been quite stable. There have been a couple minor fixes, which I will report on later, but no major problems. The biggest surprise to me has been the popularity of 64-bit computing.

I'd also like to repeat that MODFLOW-NWT looks like it should be released by the USGS any day now. As I mentioned previously, we will post an update to Groundwater Vistas as soon as that occurs. And we are still planning on releasing a version of MODFLOW-USG at the MODFLOW2011 conference. Thanks to Sorab Panday for that!

cloudPEST Presentation

2011-04-07T08:49:00.003-04:00

Mike Fienen from the USGS has agreed to give a guest lecture on cloudPEST at the GV/PEST Webinar in May. The presentation is tentatively scheduled for Thursday, May 12 at 3 pm Eastern time. The last lecture in the GV/PEST Webinar is the following day and will cover BEOPEST and other related issues so the timing should be good. There is still some room in the Webinar if you would like to attend. For more information see our web site or click here.

cloudPEST

2011-04-05T13:44:00.002-04:00

The USGS (Michael Fienen, Thomas Kunicki, and Daniel Kester) has recently released an interesting project called cloudPest. It is a series of python scripts that can be used to automate the use of Amazon's Elastic Compute Cloud (EC2) with beopest. You can download the report and code from here. I have not had a chance to try it yet but hope to in the near future.

New Versions Posted

2011-04-03T13:41:00.002-04:00

I uploaded Groundwater Vistas Version 6 (32-bit and 64-bit) and AquiferWin32 to www.groundwatermodels.com. The online store also has the updated price and versions. Here are a few things to remember:

If you have the standard version of Groundwater Vistas 6, do not install the 64-bit version.
If you have a 32-bit version of Windows, you need to install the 32-bit Version of Groundwater Vistas 6, even if you have the Advanced or higher versions.
AquiferWin32 now includes Winflow/Wintran.
You must return your existing hardware locks after receiving the new ones. If you need to use the older versions for a while, we can give you a security code.

One final note on MODFLOW-USG... This version of MODFLOW will be released at the MODFLOW Conference on June 6. I had indicated in my recent Webinar that it would be in the first release of GV6. My apologies.

Software Release on Monday.

2011-04-01T09:11:00.002-04:00

We are still on schedule to release the new updates for Groundwater Vistas 6 and AquiferWin32 V4 on Monday. Thanks to those who participated in yesterday's Webinar about the upgrades. I thought it went very well and received lots of good feedback on it. For those of you that could not attend one of the sessions, I recorded them. I uploaded the best one to our web site. You can either download it from there or click here to get the recording.

As I mentioned yesterday, I will hold one of these free Webinars each quarter to keep you up to date on what we have changed in our software and what we have planned. The first one will likely be in late June or early July. I will post a message here and on groundwatermodels.com when I have a firm date.

MODFLOW 2011 Seminar

2011-03-24T08:04:00.002-04:00

I know it's still a couple of months away but our 2-day seminar following the MODFLOW2011 conference is filling up. We have about 10 slots left. If you want to attend, please let me know as soon as possible (jrumbaugh@groundwatermodels.com). I suspect it will be full before the end of April.

If you missed my previous post on this topic, I am holding a 2-day seminar at the Golden Hotel in Golden, Colorado on June 9 and 10. This is the Thursday and Friday following the MODFLOW Conference at Colorado School of Mines. This course is not associated with the conference. The cost is $450.

The seminar will be given by me, John Doherty (author of PEST), and Sorab Panday (author of MODFLOW-SURFACT and the new MODFLOW-USGs). I will be discussing the new features in both MODFLOW and Groundwater Vistas. John will be talking about the latest PEST enhancements, along with a bit of philosophy. Sorab is going to present his latest creation called MODFLOW-USGs, which is a new version of MODFLOW for unstructured grids. Should be a very interesting time.

New Software Version Information

2011-03-22T15:38:00.002-04:00

The links to the free Webinars have been posted on www.groundwatermodels.com. Just go to the main home page and click the one that best suits your schedule.

We also have a link to additional information, including prices, for the new versions of Groundwater Vistas and AquiferWin32 (including Winflow). Or just click here for that pdf document. If you have any questions about the new versions, feel free to send an email to jrumbaugh@groundwatermodels.com.

Free Webinar on GV6/Aquifer 4

2011-03-18T08:35:00.003-04:00

I will be presenting a free 1-hour webinar to describe the new features in Groundwater Vistas Version 6 and AquiferWin32 Version 4 on March 31. In order to allow users in other parts of the world to participate, I am scheduling three sessions. These include:

9:00 am Eastern Time
3:00 pm Eastern Time
8:00 pm Eastern Time

I will be posting links on the main page at www.groundwatermodels.com next week. Or send me an email and I can provide a link that way.

Release Date for New Versions

2011-03-14T10:58:00.003-04:00

Big news... We will release Groundwater Vistas Version 6 and AquiferWin32 Version 4 on April 4, 2011. Here are some highlights of this release:

Groundwater Vistas 6

A native 64-bit version will be included in the Advanced, Professional, and Premium versions (but not in the standard version)
A new Premium level has been added which includes the SAMG multi-grid solver for MODFLOW2000 and MODFLOW2005
All supported models are updated to the latest versions
Models run much faster in GV6

AquiferWin32 Version 4

Winflow and Wintran are included now in AquiferWin32
There is only one version which is equivalent to the old Modeling version.
This means significant new functionality for existing AquiferWin32 Professional and Winflow/Wintran users

A more complete list of enhancements, along with pricing, can be found by clicking here.

We will also have a free webinar near the release date to show you the new software. Stay tuned...

MODFLOW2000 moved to Legacy Status

2011-01-31T09:40:00.003-05:00

The USGS recently moved MODFLOW2000 to it's "Legacy and Superseded" software area to keep MODFLOW88 and MODFLOW96 company. This apparently means that MODFLOW2000 will not be updated in the future and will be finished at version 1.19.01. I am not 100% convinced that MODFLOW2005 is totally ready for prime time but we'll see. We will be switching to the same compiler the USGS uses for MODFLOW2005 when we come out with GV Version 6 so that should help.

Webinar Dates in 2011

2011-01-03T08:49:00.002-05:00

I have posted new dates for our 3 webinars in 2011. These include:

Introduction to Groundwater Modeling with Groundwater Vistas:
March 14 through 25

Getting the Most Out of Groundwater Vistas:
April 4 through 8

Modeling Calibration with PEST and Groundwater Vistas:
May 2 through 13

You can find out more information about these Webinars at GroundwaterModels.com and click the Webinars button.

Happy New Year!

New Calibration Target Type

2010-12-22T08:40:00.002-05:00

We recently added a new calibration target type in Groundwater Vistas called the flow direction target. This may be a bit confusing because we also have a gradient target. The latter is made up of a triangle of 3 head targets linked together to define the direction of flow at the centroid (and optionally the magnitude of the gradient). The flow direction target, on the other hand, is a point observation of flow direction. If you define a target in Vistas and pull down the list of target types at the top of the target dialog, you'll see "flow direction" way down the list. The target value in this case is the direction of flow. The direction is a mathematical angle so zero degrees is East, 90 degrees is north, etc.

The general idea behind the flow direction target is to match contaminant plume movement in a flow calibration. One of our users recently tried this by putting flow direction targets down the center-line of a plume and then using pilot points for hydraulic conductivity with Pest. The result was a very good match to the observed movement of the plume without having to calibrate the transport model along with the flow model.

Abstracts due for MODFLOW 2011

2010-12-17T08:47:00.003-05:00

Just a reminder that abstracts are due Monday for the MODFLOW 2011 Conference. As I mentioned in a previous post, this is a great conference. Even if you cannot present a paper or poster, I hope to see you there next June. Here is the link for submitting abstracts (hint, hint...)

http://igwmc.mines.edu/conference/abstract.html

Happy Holidays!

MODFLOW 2011 Conference

2010-11-22T07:50:00.002-05:00

There will be another MODFLOW conference at Colorado School of Mines June 6-8, 2011 in Golden Colorado. I always enjoy this conference and recommend it to anyone interested in MODFLOW and groundwater modeling in general.

After the conference I will be holding a 2-day seminar at the Golden Hotel. The seminar will be Thursday and Friday, June 9 & 10. This seminar will be different from my usual seminars and Webinars in that it will cover a wide range of topics. John Doherty will be presenting the latest enhancements to PEST. Sorab Panday will be discussing his new unstructured version of MODFLOW. And I will be covering the new features in Groundwater Vistas 6.

Please note that my seminar is not an official part of the conference so if you want to sign up, just send me an email. The cost will be $450 and limited to 25 participants. You do not have to attend the conference to attend this course.

Many of you know that Groundwater Vistas Version 6 is coming out soon, but please don't send me an email asking for the release date, list of features, cost, etc. All I can say at this point is that it will be released well in advance of the conference. You will hear more from me in this blog and via emails from our web site as we get closer to the release.

Using Multiple Recharge Arrays

2010-11-15T07:55:00.002-05:00

I have had a few requests over the years to allow multiple recharge arrays in Groundwater Vistas. Unfortunately this has some serious memory ramifications because Groundwater Vistas stores all recharge and ET transient data in memory. Also, MODFLOW only has one recharge package.

There are times, though, when it is advantageous to be able to track recharge from different sources separately. To help with these situations, we have added a new feature to Groundwater Vistas under Props|Import|Matrix. A checkbox labeled "Add this matrix to existing property data" allows you to keep recharge arrays in matrix format outside of Groundwater Vistas. To assemble a final recharge distribution, you just import all of them using this "add" option. The one limitation is that the property (e.g. recharge) must be stored using the matrix format in GV and not the zone database format.

With this option, you can establish a recharge distribution and save it to a matrix file (Props|Export|Matrix). After all recharge sources have been accounted for in separate files, you simply create a GV file with all recharge sources added together.

To help use this feature with Pest, we have created a utility program that can add recharge matrices together after applying multiplication factors to all or part of the matrix file. Using this utility requires you to make changes to the Pest files outside of Groundwater Vistas but we can provide this utility to you if you need it.

Groundwater Vistas 5.48 Build 2 Update

2010-11-11T12:57:00.003-05:00

Here are the latest changes to Groundwater Vistas between 5.47 Build 9 and the current one which is 5.49 build 2:

Enhancements:
- Added the rclose variable to the PCG4 solver input for MODFLOW-Surfact

- Flow Direction calibration targets are now functional (note that the angle for flow direction targets is the mathematical angle where zero is East, 90 if North, etc.). These work both in Groundwater Vistas and in Pest.

- Added a range in reach numbers for use in endpoint analysis (previously only a single reach number could be entered for the purposes of endpoint analysis)

- The "no transport" option was added for use in SEAWAT2000. With this option only the density or concentration is specified for each cell. SEAWAT2000 will then use this density as a given and not run any transport simulations with MT3D.

Minor Changes & Bug Fixes:
- The gage package was not being written for MODFLOW-Surfact

- Changed the format of values in the TMP1 Package to exponential

- Simplified Boundary Condition editing was not changing transient values of Kv

- In the RSF4 Package, the IRCH array was being written out of order (note there are errors in the Surfact manual about this)

- Velocity vectors in cross-section could potentially be displayed with the wrong color indicating upward flow with the downward color (and vice-versa)

- A memory error was discovered when exporting the HSU report for mass balance. (It seemed to only happen in Windows XP).

Groundwater Vistas & Pest Webinar

2010-10-12T19:06:00.004-04:00

The next model calibration Webinar will held from November 8 through 19. This Webinar is focused on using Groundwater Vistas and PEST to calibrate groundwater flow and transport models. You can get additional information at our web site (www.groundwatermodels.com - click the Webinar button).

Two new topics will be covered in the November webinar. The first is a detailed discussion BeoPest, the newest version of Pest. BeoPest replaces Parallel Pest and allows users to connect computers in different locations, including cloud servers. We recently tested BeoPest by using computers in the USA and Australia on the same Pest run. As part of the BeoPest lecture, we will also cover the use of GoGrid cloud servers in Pest simulations.

The second new feature is a guest lecture by John Doherty, the author of Pest. John will discuss the latest developments in the Pest technology and share his thoughts on the philosophy of model calibration and uncertainty analysis.

Experiences with BeoPest and GoGrid Cloud Servers

2010-10-11T09:18:00.003-04:00

I have had a chance recently to work with BeoPest and GoGrid cloud servers. BeoPest is the latest version of Pest that replaces parallel pest, allowing you to more easily connect multiple computers in the same pest run. It is much easier to use than parallel pest and works by using TCP/IP. The latter means that computers do not need to be in the same location. I recently tested this with John Doherty (author of Pest) where the master run was here in Pennsylvania and several slaves were running on John's computers in Australia. It worked flawlessly.

I am also now using GoGrid.com's cloud servers to run slave runs with BeoPest. It is fairly economical if you just need lots of computers for short time periods. I have been using Windows Server 2008 (64-bit) servers with 4 Gb of RAM. This gets you 4 processors on each server so you can run 4 separate slave runs on each one. I found the GoGrid.com servers to be extremely fast and have not had one go down yet. They are virtually the same speed as my newest Alienware Area-51 workstations that use the new Intel 6-core i7, overclocked at 3.6 Ghz. That is pretty amazing speed. Cost for each server is $18.24 per day, which is $4.56 per day per slave run. That amounts to about 200 days of slave runs to pay off an Alienware workstation. Since most Pest runs are intensive for short periods, it makes sense to use these cloud servers.

A Note on Windows 7

2010-10-07T11:36:00.003-04:00

We are getting a lot of emails on Windows 7 compatibility and our software. All of our products (Groundwater Vistas, Winflow, and AquiferWin32) work fine under both the 32-bit and 64-bit versions of Windows 7. There are a couple of things to note, though:

- We use WinHelp format help files. Windows 7 does not automatically install that but you can download it from the Microsoft Web page. Actually when you try to access help for the first time, Windows 7 tells you the problem and directs you to the download area, so that is easy to solve.

- There are some occasions when Groundwater Vistas gets stuck continually refreshing the screen. This only seems to happen when screen refresh takes a long time (e.g. lots of large maps and other things to draw). You can stop this by maximizing another window over top the Groundwater Vistas window and waiting a few seconds. When you go back to Vistas, it will be fine. Let us know if you encounter this - so far it seems fairly rare.

Latest Groundwater Vistas Changes

2010-10-07T11:05:00.003-04:00

The last few months got away from me. It's been a long time since I posted to my blog so I'll start getting caught up by listing the changes to Groundwater Vistas Version 5 since my last post.

Enhancements

Additional options under ae|modify|well|flow rates
Added option to animate particle movement (File|Export Animation)
Added seawat2000 drain option
Made transient hsu report
Additional particle export options
Added RMS error to calibration stats.
Mass Balance hydrograph on current hsu can graph contributions from adjacent hsu's
Recharge multiplier by hsu zone range
Export mnw/fwl stuff to well shapefile
Turn on/off well names based on being selected
Import segmented et data
Export dry/flooded cells when exporting cell/nodal results
Add x,y to dry and flooded cell reports
Support fwl5 package in mass balance
New "add" option on props|import|matrix (add imported matrix to current property)
Option to not write out data from Stress Periods with zero rates in AE wells export
Dry cell report now lists dry wells
Added IBS to mass balance (addition to storage term)
Support for Leapfrom Hydro 3D Geologic modeling
Added support for Surfact TMP1 package (change Kx, Kz, Ss, Sy with time)
Added automatic renumbering of pilot points
Added prior info to mf2k pes package
Added plot|file operations|mean-stddev to compute mean of a range of stress periods

Bugs Fixed

Needed to add KMAKR to pestgv.bat file for "krige by layer"
Fill in gaps pilot point routine did not work with multiple layers.
Plot|Next time step was not working with surfact mixed steady and transient periods
Lake conductance for LPF changed in concept, with support for legacy models
Cross-section color flood problems fixed
Problem identified in mt3d with 1000 rows
Problem estimating ET extinction depth with pest when ET rate is constant
Polyline transient problems fixed
Seawat/mt3d unit numbers (added 200) due to conflict with pilotpoints
Do not put targets/wells in dxf export if not drawn on the screen
Transient target missing last time value in shapefile import
If nlay is exactly 200, laycon array has one extra line in it
Bug in exporting transient streams to ascii file
Bug in writing kz.tpl for surfact when estimating kz & writing kz to bcf package
GWM testing complete with several bugs fixed
Bcs|import|text not whiting out duplicates in same cell
Polyline was not saving bottom layer number
Fixed some problems importing pcn file from surfact
Gw3d had problems with ato package in Surfact

Groundwater Vistas & Pest 12

2010-03-01T09:41:00.002-05:00

We recently updated Groundwater Vistas to work with the latest version of PEST (version 12.0). When you install the update for GV Version 5.40 build 5, it installs the latest Pest software (only the parts that Vistas uses). We have tested the interactions between Pest and GV over a wide range of options. However, if you encounter a problem, please bring it to our attention. For more information on Pest 12, go to the new PEST web site at www.PESThomepage.org.

Also added in this new version of Vistas:
- The export of a text file matrix from the matrix editor puts all columns of data on one line.
- There is a new option to export Boundary Condition wells in Analytic Well format to facilitate moving wells from one type to the other.
- There are new options for posting of data at calibration targets. These include the mean residual, maximum residual, RMS error, sum of errors, and sum of absolute errors. These are intended for transient targets with lots of data. The values also control the size/color of the residual circles. You can select these options under Plot/Calibration/Options.
- Flooded cells added to the legend
- Transpose and Transpose Window commands now have an option to operate on all stress periods for Recharge and ET.

Bugs fixed:
- Telescopic Mesh Refinement (TMR) did not work correctly with MODFLOW-Surfact variably saturated runs.
- Modified the output of Kx pilot points to the Pest control file to use exponential format when the values are small.
- Various problems encountered with the new "krige by zone" option in PEST.
- Some problems occurred if you were using the LPF package for flow but had the "compute leakance" flag off. Obviously this flag should not affect LPF, but there were some problems related to Pest if it was not checked.

Happy New Year - Latest in Groundwater Vistas

2010-01-08T13:12:00.003-05:00

My New Year's resolution is to keep up with this blog in 2010!

Here are the new features added to Groundwater Vistas since 5.33 Build 25 (current version is 5.39 build 16):

- GV now ignores zero conductance boundary conditions on import.
- We have a new Color Flood Setup on the plot menu to change color ramp
- The monitoring well hydrograph has a new option to plot both head and drawdown
- Stream width has been added as a transient parameter on the shapefile import
- Pilot point calibration with Pest has a new "zone-based" kriging option
(this allows you to have the same K values in each zone regardless of which layer
they are in)
- If you specific negative concentrations in an injection well (BC wells only), GV interprets this to be a mass flux boundary condition in MT3D
- Under Plot|Calibration|Options, there is a multiplier for concentration targets.
(this allows you to simulate concentration in one set of units but have target
concentrations in another set of units)
- There is a target time shift option (AE|Modify|Targets|Time Shift)
- Targpest is now much more efficient in dealing with transient flux targets
- There are now recharge multipliers for each stress period (Props|Property Values|Recharge Multipliers)
- These recharge multipliers are also Pest parameters
- Particle ID values are now exported in shapefile attribute database
- Lakes can now be imported from polygon shapefiles
- Added anisotropy zone as an estimable parameter in Pest using LPF/MF2K
- If the working directory is not found, GV tries all possible drive letters before reporting it cannot find the directory
- Added support for importing models created by ARANZ Hydro (3D viewer)

And here are those pesky bugs we fixed:

- Problem importing results from a SURFACT run with multiple components and dual-domain transport
- GHB cells gave an error when using update TMR function.
- Errors occurred when using pilot points with SURFACT in confined layers when using the variably-saturated option.
- GV was not properly writing THTI values in UZF Package of MODFLOW2005
- BMP logo in page setup for cross-section printing not working.
- GV was not writing concentrations to FWL5 files for MODFLOW-Surfact
- CHD file import was not working for the case of multiple CHDs in the same cell.
- Problems with reverse particle tracking with MODFLOW-Surfact and ATO Package.
- Surfact RSF concentrations were not output for the case when all recharge values are constant
- Error messages occurred when converting recharge from matrix format to zone format
- Posting of residuals in MODFLOW88/96 simulations with multiple steadystate stress periods did not work properly
- Pest regularization problems when using new zone-based kriging.
- GV was not importing mass balance data for Reservoir Package.
- Error message occurred when the simulated target hydrograph starting with time = 0

Cloud Computing

2009-12-02T09:38:00.002-05:00

One of the most interesting things to come out of the Pest conference last month was the ability to use "cloud" computers as a pest nest (a network of computers to run parallel pest). Cloud computing seems to be the latest buzz-word in tech but looks like it could be very useful in groundwater modeling, especially for situations where run-times are long and you may not want to tie up your own computer to do the runs.

In cloud computing, you rent a server (or as many as you need) from a company like Amazon or GoGrid.com. You then load your software and data files on it, fire up the model, and log in later when it's done. The costs are very reasonable (~ $5 per day).

I have tested this on GoGrid.com and have a draft tutorial on how it works. There will also be a new version of parallel pest to work with this, along with other auxiliary software to make it all work better. If you are interested in the tutorial document, just send me an email.

Native 64-bit Groundwater Vistas

2009-09-15T09:52:00.002-04:00

I know that version 6 of Groundwater Visas is overdue and we are working hard on it. One new thing that will be in Version 6 is a native 64-bit release of our software. This release will have 2 distinct advantages: (1) access to lots of memory, and (2) speed. As a test I ran the benchmark simulation mentioned in my previous 2 posts on the i7-975 using a beta version of GV6-x64. It ran the simulation in 2 minutes 15 seconds or almost twice as fast as version 5 running in 32-bit mode. I think the combination of the i7, 64-bit Windows, and Groundwater Vistas x64 will be a huge step forward in simulation speed.

More on the i7 chip

2009-09-04T20:54:00.003-04:00

As I mentioned in my last post, I just built a new system based on the Intel i7-975 chip running at 3.33 Ghz. If you recall from the last post, my benchmark run took 5 minutes 8 seconds on a 2.66 Ghz i7. The same benchmark took 8 minutes 53 seconds on a 3.00 Ghz Xeon system (what I used to think was Intel's fastest processor for modeling). The new system, though, runs the same benchmark in 4 minutes 8 seconds, or about 20% faster than the 2.66 Ghz i7. It's hard to believe this is over twice as fast as a comparable Xeon.

So, if you are concerned about run time, get an i7 system!

Modeling and Gaming?

2009-08-31T14:16:00.002-04:00

I am often asked for my opinion on what is the best computer to get for groundwater modeling. In the past, I recommended Intel's Xeon processor that is used in servers and high-end workstations. I always thought that was the fastest chip for modeling.

I never had the chance, though, to test out Intel's relatively new Core i7 chip, mainly because these chips usually show up in gaming computers. A colleague just purchased a really cheap Core i7 computer from Costco. This system was based on the low-end Core i7-920 (Nehalem) running at 2.66 Ghz.

To test out the i7, I ran a relatively complex transient simulation which takes 8 minutes and 53 seconds on a 3.00 Ghz Quad-core Xeon (X5450) system from Dell. The slower i7 ran the same simulation in 5 minutes and 8 seconds for a speed increase of 73%. Obviously the optimizations Intel added for gaming are also useful for groundwater modeling! I plan on building a new system based on the i7-975 (Bloomfield) running at 3.33 Ghz to see what the extra clock-speed can do. I will report back on what I find out.

Until then you might try to convince your boss to get you a gaming computer!

New Pest Pilot Point Option

2009-07-17T11:04:00.000-04:00

I have added a new Pest feature to Groundwater Vistas based on a suggestion from John Doherty. This new option is another way of using pilot points for model calibration. Currently, Groundwater Vistas (and all other GUI’s for that matter) adjusts aquifer properties on a layer basis. If you have a hydrostratigraphic unit (zone) that spans more than one layer, then each layer would be kriged independently. In the new procedure, you place pilot points throughout each zone but they are kriged by zone and not by layer. The same properties are used at each row,column location in each zone regardless of layer.

There are a couple of advantages of this strategy. First, you get a more consistent property distribution within each stratigraphic unit. Second, you use a lot less pilot points, which speeds up the calibration process.

The trick is to make sure you don’t have multiple pilot points at the same X,Y location within the same zone (i.e., same X,Y but different layers). To assist with this, Groundwater Vistas will check for pilot points of the same type (e.g. Kx, Kz, S, Recharge) in the same zone at the same X,Y location. If overlapping points are found, one of them is converted to a constraint target (not used by Pest). You can see these points as green symbols instead of the standard red for pilot points. If you agree with the one that has been “turned off”, then you can just delete them. If not, you can convert back to a pilot point and delete the other duplicates. This check is done when you create Pest datasets.

The new pilot point zone-based kriging is activated on the main Pest options dialog as a check-box to the right of the check-box that turns on the use of Pilot Points. You will need Groundwater Vistas version 5.36 Build 5 or higher.

Latest Modifications to Groundwater Vistas (5.33 Build 24)

2009-05-13T10:29:00.002-04:00

Well, after a long break from updating this blog, here are the latest changes to Groundwater Vistas. The current version is 5.33 Build 24.

Enhancements:
- Many changes to Focus TMR operations for SWFWMD's DWRM2 model
- The batch hydrograph function was activated (see plot/hydrograph/batch processing)
- Added 2 new residual posting options (average error and amplitude ratio) for transient targets
- Added RCL (row, column, layer) import for matrix properties (see props/import/rcl)
- Added support for combining MT3D UCN files for Plot/File Operations/Combine Binary files

Bugs:
- We added transient Kv to head-dependent boundary conditions (drain, river, etc.) in an earlier version. When importing older models, the Kv was being set to zero.
- There was a problem in some cases with color-flooding in cross-section view.
- Pest template files were not recognizing ET zones after the first stress period
- Using BCs/Modify/Copy Stress Period command sometimes caused a memory error.
- The option to reset the Initial Head property when creating the MODFLOW dataset (where initial heads were read from external sources) was not working for MODFLOW2000 models

User Alert - Please Send GWV Files

2009-03-10T10:55:00.002-04:00

When emailing us about technical support questions, please include your GWV file if your question is specific to your model. You do not need to send the gwv file if you question is conceptual or general in nature. However, if you are asking about convergence issues, memory errors, display problems, or anything detailed about your particular model, we cannot answer without seeing your model. We treat every file as confidential and delete them after the question has been answered so you don't need to worry that you are violating client confidentiality.

I cannot count the times over the past few months where my answer to technical support questions is "I cannot answer that without seeing your model". I am not clairvoyant and I cannot see your computer screen from my office in Pennsylvania.

You can get your gwv file to me in three ways: (1) email it if the zipped file is less than 5 megs, (2) upload to www.groundwatermodels.com - click Clients button, (3) upload to your own ftp site. In all of these cases, though, please compress your file using WinZip or other file squashing program.

Latest Groundwater Vistas Modifications

2009-03-10T10:41:00.002-04:00

The latest version of Groundwater Vistas is 5.33 Build 13. Here are the modifications since my last posting:

Enhancements:
- Added zonebud format to Props/Export/Zone Numbers
- Changed color flooding of properties with bitmap map files to make it easier to see the colors
- Added prompt to repair streams after xyz file import
- Added Pest option to have negative RLAMFAC value
- Added sub-space enhanced Tikhonov in Pest 11.8 (note that Pest 11.8 not yet added to Vistas as we have not yet confirmed it works properly
- Added option to always draw wells regardless of which layer you are viewing
- Added transient SFR import of precip, et, runoff, and flow from text file
- Added column headers when copy/pasting from spreadsheets
- Added river bottom elevation to simplified BC editing
- Allow uncoupled transport simulation in SEAWAT2000
- Added reach number range for copying transient BC data and BC cycles

Bugs Fixed:
- Export of HFB (walls) to shapefile not working in rotated models
- Various bugs fixed for GWM
- When importing streams from text file, the reach number was always 1
- Problem with GHB file in MODPATH when GHB head was negative
- Problem importing RES input file without name file
- Gradient targets not exported properly to shapefile
- There was a problem using the DDREFERENCE flag in output control with MF2k5
- BCs/Modify/Copy Stress Period could give memory error if there were mixed steady and transient BCs and the user chose not to convert steadystate to transient
- Updating recharge pilot points after Pest run did not work properly.
- When using Pest with Kz pilot points, sometimes not all the *._kz files were written out.
- UZF Package option to use HSU zones as layer numbers did not work
- Layer number not exported to shapefile for no-flow cells
- Problem importing EVS GVG file when more than 30 layers
- Lake BCs in TMR files sometimes did not import properly

Other Seminar Opportunities

2009-01-07T09:37:00.002-05:00

In addition to the scheduled seminars listed below, there is another option for hosting a seminar in your area. If you can round up 8 people to attend a seminar at $1,200 each for 3 days I will hold the seminar at that location. This type of seminar must be scheduled at least 4 months in advance.

2009 Seminars

2009-01-06T14:17:00.001-05:00

I have scheduled three seminars for the first part of 2009. These include the Introduction to Groundwater Modeling Seminar, the Advanced Topics (Calibration, Uncertainty, and Optimization) Seminar, and a 0ne-day Seminar on the District-Wide Regulation Model (DWRM) and Focus TMR for those of you that work on water use permits in the Southwest Florida Water Management District. Click the links below for more information or visit our web site at www.groundwatermodels.com

March 25-27, 2009 in Valley Forge, Pennsylvania - Intro seminar

April 15-17, 2009 in Tampa, Florida - Advanced seminar

April 14, 2009 in Tampa, Florida - DWRM/Focus TMR seminar

You can get more information from our web site:

http://www.groundwatermodels.com/Seminars.php

Happy Holidays!

2008-12-23T16:12:00.000-05:00

We hope you have a Happy Holiday season!

From now until January 5, we may be a bit slow in responding to email. We apologize in advance if you have to wait longer than usual for answers to your questions.

Jim Rumbaugh
President
ESI

New Features in GV5.30 Build 2

2008-12-12T11:08:00.002-05:00

It's been a while since I posted the changes made to Groundwater Vistas. Here is a summary of changes since V5.26 Build 2:

- The matrix calculator now has the ability to limit calculations to a range of HSU zone numbers

- The HUF Package will now save heads and flows for HUF layers to files compatible with GV. To import these results, however, you need a version of your model with the number of layers equal to the number of HUF layers. (See previous post on use of HUF in GV)

- Time can now be displayed in titles (AE/Title) using the code #1# (number one between#). When GV sees this in a title, it takes the simulation time you have imported for contouring multiplies by a factor and adds to a base value. The base and multiplier are set under model/notes/model description

- The HUF Package has been hooked up to Pest. Each HUF layer is treated as one parameter so the all K values in the layer are scaled proportionately. When using HUF and PEST, the Kx and Kz parameters in the parameter spreadsheet are set with the zone number equal to the HUF layer number.

- Added Reservoir Package (RES) - see prior post on this issue.

There were also a few bugs fixed:

- Line boundaries were not hooked up to the SSM package in MT3D
- Still a few issues with generating SFR2 input files due to ambiguity in SFR manual
- MF2005 requires first line of BCF to be read list-directed contrary to the manual
- There was a problem with color-flooded user variables if they were not also the contour variable
- Using AE/Modify/Pilot Points/Reset from Database did not work on recharge and storage points
- Exporting walls (HFBs) to shapefile did not work when the model was rotated.
- Continuing memory problems with MODFLOW2005. We fixed a few more issues but there are still likely many remaining. If you have problems, send us your model. Note this is an issue with the original USGS code and not with Groundwater Vistas.

No More ftp

2008-12-11T07:31:00.001-05:00

We have closed our anonymous ftp site in favor of using our web site. If you were used to checking ftp.modflow2000.com for software updates, you will now need to go to http://www.groundwatermodels.com and click on the Clients button. Create a login and then you will see the various files available for download. There is also an upload area where you can either drag a file into the upload bar or click browse to find the file that way. If you do upload a file, be sure to send us an email letting us know it is there.

Reservoir Package in Groundwater Vistas

2008-12-10T10:49:00.001-05:00

The Reservoir Package (RES) is an old one for MODFLOW but we never supported it because it did not seem to get much use. However, we have seen a couple of models lately that use it so we just finished putting the RES package in Vistas. You can get the update (5.30 build 2) from our web site at www.groundwatermodels.com and click Clients.

Reservoirs are special versions of Lakes in Vistas. So you add them by using BCs/Lake. You'll see a check-box on the dialog that says this is a reservoir. Then some fields will be grayed out and others will have different labels according to what the RES package needs as opposed to the lake package. RES package is turned on and cell-by-cell flow unit number set under model/modflow/more packages. The few options are set using model/modflow2000/options - Lake3/RES tab.

ZoneBudget with Groundwater Vistas

2008-12-10T09:36:00.001-05:00

You can use zonebudget from the usgs with Groundwater Vistas. Make sure to get the very latest one (http://water.usgs.gov/nrp/gwsoftware/zonebud3/zonebudget3.html). Easiest thing to do is after unzipping, copy the file zonbud.exe to the gwv5 directory. To run it, open a console window in the working directory (find the working directory in Windows Explorer, right-click, and choose "open console here".) Then type zonbud and hit enter. One thing it will ask for is a zone file. To get that, in Groundwater Vistas 5.30 Build 2 and later, use Props/Hydrostratigraphy and then Props/Export/Zone numbers. Remove the first check so that all layers are exported and then check the last item to save in zonebudget format. That is the file that zonebudget will eventually prompt for. Also, you'll need to save all cell-by-cell flows to the same unit number so they are all in one file if you want all components of the budget in one run.

Groundwater Model Server

2008-11-21T09:41:00.002-05:00

Over the coming months we will be launching a new web site called GWModelServer.com where we will post groundwater models from all over the US (and other countries if possible). The idea is to preserve as many models as possible so all of the knowledge gained during these studies is not lost. We will be hunting down models from the USGS, State Agencies, Universities, etc. Each model will have an electronic report, original model input/output files, and where possible a Groundwater Vistas file. The latter is the self-serving part of this endeavor :-) to benefit our user base. Otherwise it is primarily a community-service project.

So... If you can contribute a model from the public domain (nothing proprietary please), we would greatly appreciate it. You can send me an email (jrumbaugh@groundwatermodels.com) or upload to our current web site (www.groundwatermodels.com - click on Clients).

Subsidence Targets and Other Stuff

2008-10-28T07:33:00.002-04:00

We just added a new target type for land subsidence. This is way down the list of target types. Currently, this new target only works with the older IBS (Interbed Storage) Package but we will also be working on hooking it up to the newer SUB Package. Along with the Subsidence target is the ability to estimate elastic and inelastic specific storage in the IBS Package with Pest. Again, this parameter is way down on the list of Pest parameter types in the parameter definition spreadsheet in Vistas.

You will also see another type called "flow direction". That is not hooked up yet but will be shortly. It will be used to calibrate flow directions as an alternative to the "gradient" target in Vistas. The gradient target is defined from three adjacent head targets using the 3-point problem. The "flow direction" target, on the other hand is simply a point where you define the flow direction (with zero degrees being East, 90 is north, etc.). More to follow in this blog once it is finished.

We also improved the animation export in Vistas. In very large or long model runs, the bitmaps sometimes would quit being updated in later time steps. This works better now but is not fool-proof. If you run into this problem, there is a new option in the animation export to start the animation at the current time step. So find out where your bitmaps quit being updated, import the results for that time step and re-export the animation from there. Note that the file naming and numbering will be consistent with the whole run so that when the animation is finally created, it will be one seamless video.

Also, a few other changes:
- Improved color floods for models with extreme grid spacing changes. In the past you could get a white checker-board effect which is now resolved.
- A few MODFLOW2005 issues were fixed (did not like spaces in the path name, STR Package formatting was incorrect in certain instances, and the highest active layer option in ET was not working correctly)
- Plot/File Operations/Extract was confusing CBB with UCN files
- Stream shapefile import for polylines was not working correctly with tributaries
- Importing an existing SFR input file was not working if some stress periods used the -1 option to use the previous stress period's data
- In dual-domain MODFLOW-SURFACT runs, Vistas was importing the concentrations from the immobile domain instead of the mobile domain

First PEST Conference!

2008-10-06T07:13:00.002-04:00

On behalf of John Doherty, Matt Tonkin, and myself, please consider joining us at the first-ever PEST conference!

This first-ever PEST Conference will be held in The Stained Glass Hall of the Bolger Center, Potomac, Maryland ( http://bolgercenter.dolce.com/<http://bolgercenter.dolce.com/> ) November 2nd through 4th, 2009. The primary goal of the PEST Conference is to bring together modelers from a wide variety of disciplines who either have experience in, or would like to learn more about, the use of inverse modeling techniques - i.e., parameter estimation and uncertainty analysis - with a particular focus on the PEST suite of programs (www.sspa.com/pest ).

The objective of bringing together modelers from a variety of modeling disciplines is to exchange ideas, discuss applications of the PEST suite of programs, share lessons learned, discuss new and planned developments, and seek guidance from modelers on inverse modeling needs to guide future code development. It is also hoped that this forum will provide an opportunity for modelers to meet and discuss novel approaches that they have taken to solving problems that they have encountered.

The PEST Conference will commence with a message from John Doherty, the developer of the PEST programs. John will provide some history of the development of PEST, discuss wide ranging applications of PEST, outline planned future developments, and doubtless wax lyrical on a great many other topics! The conference will follow with morning and afternoon sessions, each
commencing with a key-note address given by a noted environmental modeler, followed by submitted oral presentations. A poster session will also be held one evening. Oral and poster presentations will be summarized in extended abstracts and/or full papers that will be published in electronic proceedings distributed on thumb drives. The conference will wrap up with a
question-and-answer session during which attendees will be able to ask questions of the organizers and of John Doherty, in particular, and provide suggestions for future development directions.

A one-day Introductory PEST course will be held immediately prior to the conference, and a two-day advanced PEST course will be held immediately following the PEST Conference, with instruction from John Doherty, Jim Rumbaugh, and Matt Tonkin.

Further information about the PEST Conference - including the list of keynote speakers and information on registration, accommodations, and travel, will be posted soon at www.sspa.com/ThePESTConference.

We hope to see you in November 2009!

Analytic Elements & Python

2008-09-27T09:04:00.002-04:00

It's not often I get to attend a seminar as a participant but I had that chance last week at a seminar taught by Mark Bakker (http://www.bakkerhydro.org) and sponsored by SS Papadopulos & Associates (http://www.sspa.com). The topic was the analytic element method and programming in Python. Excellent seminar - highly recommended.

I now understand the hype around Python. It really is a powerful tool and easy to learn (especially if you know a little C or C++). Mark has written his TimML (multi-layer analytic element model) in Python, although the focus of the seminar is writing your own simpler analytic element models. Once you do that, though, TimML is easy to use since the concepts follow from the simpler models.

Look for TimML integration into Groundwater Vistas in the near future! It's multi-layer structure really lends itself to a MODFLOW-style environment.

Transient Boundary Conductance

2008-09-27T09:00:00.001-04:00

New in Groundwater Vistas 5.25 Build 2 is the ability to make conductance vary with stress period for rivers, drains, and GHBs. The "K" parameter is now on the transient data spreadsheet for these boundary types. When reading in an older GV file, the default K is placed in the spreadsheet making this backwards compatible with all models. Note that Streams already had a time varying conductance through transient width term.

New Pest SVD Strategy

2008-09-18T12:55:00.002-04:00

John Doherty recently suggested a new strategy for using Singular Value Decomposition (SVD) in Pest. This may be a bit confusing because the acronym SVD is used in two different ways in Pest and in Groundwater Vistas.

Many of you may be familiar with SVD-Assist, which is a way of reducing the number of estimated parameters, especially when calibrating a highly parameterized model (e.g. with pilot points). In Groundwater Vistas Advanced version, this is found on the Model/Pest/SVD Assist menu. To use this procedure, just start at the top and work down one menu item at a time. There are two big advantages of using SVD-Assist. The first is that you can often reduce the run time by a factor of 10. This is done by estimating a linear combination of model parameters called a super parameter. The number of super parameters is often only 5 to 10 percent of the total number of parameters. The utility SVDAPREP does all the work - you just need to tell it how many super parameters you want to use. The number of super parameters can be estimated using the utility SUPCALC (also now accessible in Groundwater Vistas on the SVD Assist menu). The other advantage is that the solution to the inverse problem is often more stable using this approach.

The other SVD used by Pest is a series of options in the Pest Control file. In Groundwater Vistas, this is accessed through Model/Pest/Options at the bottom of the dialog. Simply turn on the option that says "Use Singular Value Decomposition". The other key parameter here is the Eigenvalue threshold below the check-box. When using this type of SVD, the computational effort is the same as a normal Pest run. However, after making the model simulations to assemble the Jacobian Matrix, Pest will not try to estimate parameters that are insensitive (as determined by the Eigenvalue Threshold). This also makes the estimation more stable.

The new strategy suggested by John is to use both together. That is, you use SVD-Assist as you normally would but also turn on the regular SVD within the Pest Control file. In this way, if there are super parameters that are insensitive, Pest will not try to estimate them. The two SVD techniques together make the estimation even more stable. John suggests using an Eigenvalue Threshold of 1e-6 and estimate a few more super parameters than you might ordinarily try to estimate.

GV 5.22 Build 4

2008-09-09T09:14:00.002-04:00

There have been a few changes lately to end the summer, mostly enhancements:

- We added a quick animation feature to Vistas. Use File/Export Animation. GV will automatically import each time step, starting with the first one and refresh the screen, capture what is there, and export to a bitmap file. Then it will mash them together into a video. If your model is big and/or you have lots of time steps, this may take a while so be patient.

- You can display flooded cells (where water table is above top of layer 1), but sometimes it is handy to figure out how flooded they are. There is a new option under plot/what to display where you can plot only those cells that have at least a certain height of water above the top of layer 1.

- When importing existing models, you are often left with transmissivity and storage in the property databases for confined layers. In many cases, though, it would be handy to have these values listed as K and specific storage (Ss). There is a new option under Props/Property Values/Math Functions where you can divide by layer thickness. Note that this works on all layers if you use that option, and does not discriminate between confined and unconfined layers.

- Modified shapefile export for head-dependent BCs (GHB, river, drain, stream) to export the full conductance and all components of the conductance term. In addition, stream exports now include tributary segments, diversion segment, and reach numbers. On import, you can also now import tributary segment numbers and diversion segment number.

- Lake BC cells were not being split in the same manner as other BCs when adding rows or columns. This was corrected.

Summer Updates

2008-08-19T15:17:00.002-04:00

Well, the summer has been bad for blogging - too much travel I guess. There have been a few modifications to Groundwater Vistas over the past month or so. Here are the latest changes:

- If there was a MNW well in the same cell as a regular (BC) well, the mass balance got messed up in Vistas.

- There were some problems identified with run MODFLOW-SURFACT Version 3 with steady-state particle tracking.

- When using the skin factor with FWL5 in Surfact V3, there was a missing carriage return after the skin factor. This caused the run to crash.

- Use of the "addition" option for boundary heads in the Automated Sensitivity analysis did not work correctly when using the "super script" option.

- Increased the hardwired size of the TIMPRS (Mt3d time steps saved to UCN file) array increased from 200 to 1,000

- Introduced /v option in all model DLLs. This allows them to be more easily used in Parallel Pest runs because it changes the path from a fixed path to the current relative path.

- Under model/modflow2000/options - LAK3 tab, the number of stress periods used for memory allocation was not being displayed properly.

Long Time, No Post

2008-06-27T12:43:00.002-04:00

It has been a while since I last posted a message here - busy 6 weeks. Here are the latest changes to Groundwater Vistas up through Version 5.19 Build 5:

- There is now a function to update Telescopic Mesh Refinement (TMR) models. Until recently once you created the TMR model, there was no link back to the regional model. A function was added (Grid/Export/Update TMR). This is a 3-step procedure. First use this function to export a file from the TMR model. Next, go into the regional model and use that same function (changing the option at the top of the dialog) to import the TMR dat and export a file that will update the TMR model. Finally, in the TMR model use the function again to import that information from the parent model. The function will update wells, constant head, GHBs, Kx, Kz, S, Ss, Recharge, and Initial Heads.

- Custom contour levels were not working in the cross-section view.

- Modified the observation well export (File/Export - obs well data file type) so that multi-layer wells export the weighted average values.

- Added a decision (or logical) variable to the Matrix Calculator. So, for example, if you want to compute transmissivity but only in cells with a minimum saturated thickness, there is a flag now that will allow you to do that.

- Modified "Fix Layer Overlap" function to also fix layers where the thickness is less than a minimum value the user selects.

- There were some problems with external ET files when no-flow cells contained a very large negative value (e.g. -9999).

- Added stream BCs to the text file export function

- There were some bugs found in importing an existing UZF Package input file.

Advanced vs. Standard Versions in Vistas

2008-05-14T07:59:00.002-04:00

A common question I get about Groundwater Vistas is "what is the difference between advanced and standard versions"? Here is a quick summary of features found in the advanced and enterprise versions that are not in the standard version:

- Recharge/ET memory compression
- Support for the HUF Package (Hydrogeologic Unit Flow)
- Support for SWIFT
- Monte Carlo modeling for analysis of uncertainty
- Pest's SVD Assist automation
- Pest's Null Space Monte Carlo technique

Recharge and ET memory compression is useful when you are running a large model that has lots of stress periods. Normally GV allocates enough memory to hold all recharge and ET values for all stress periods. As models get larger and more transient, that presents a problem whereby there is just not enough memory to hold it all. In the advanced version, when GV sees this problem, it uses a compression algorithm (like WinZip) to compress the arrays. They are still stored in memory, just in compressed form.

Pest's SVD Assist is a technique that allows for much faster run times when you are trying to estimate a large number of parameters. It also removes the problem of trying to estimate insensitive parameters. Parameters are grouped into "super" parameters that are linear combination of the real parameters. Only super parameters are estimated. This usually results in about a ten-fold decrease in the number of parameters to estimate. In GV, we have made the use of this complex technique relatively simple.

Pest's Null Space Monte Carlo technique builds on the SVD Assist calibration technique. It allows you to create multiple realizations of your model that are all calibrated to a desired level of calibration quality. In the past, calibrating each realization of a monte carlo simulation was not feasible due to long model run times. Special features in the Pest technique, along with the use of SVD Assist, allows you to calibrate many realizations in a relatively short period of time. Like SVD Assist, GV has made the use of this technique straightforward.

The Enterprise version of Vistas is the same as Advanced but also adds Remote Model Launch (RML) and GW3D for 3D visualization of model results.

Note to Self - USGS Documents have Version Numbers

2008-05-05T20:42:00.002-04:00

I noted in a previous post that SFR2 (Streamflow-Routing with unsaturated flow beneath streams) is now supported in Groundwater Vistas. I did not realize at the time that I was working from the original SFR2 manual and it had changed subsequently. Many thanks to Dave Prudic for helping me figure this out. Turns out that USGS publications are not necessarily static - they have version numbering (or at least the capability for version numbering). The current SFR2 manual is called Version 1.10, April 2006.

Anyway, I noticed that something was wrong when trying to import an existing SFR2 input file into Groundwater Vistas and the format did not match the manual I was working from. This problem would also affect files created by Groundwater Vistas for SFR2 (SFR1 would not be affected and this is the default setting in GV). However, the created files would not run so if your model was affected by this problem you would know it.

Version 5.17 Build 5 fixes this problem in SFR2.

MF2K5 V 1.05.00 in GV

2008-05-02T10:12:00.002-04:00

I just uploaded Groundwater Vistas Version 5.17 Build 4. This version supports the new version of MODFLOW2005 Version 1.05.00 released earlier this week. If you are using the UZF Package, you will see one new variable called SURFDEP which is the average undulation depth at land surface and effects recharge. The default value is GV is 0.0. There is also a new option to apply recharge directly to the water table. I do not have support for that option in Vistas yet so if you need it let me know.

There is also a new variable in the PCG2 solver that allows a separate damping factor for transient stress periods when a run contains both steady and transient stress periods. I do not yet have that hooked up either.

Another addition to Vistas is post-processing for Null Space Monte Carlo runs. Testing has gone very well for this new Pest procedure. It is truly amazing what it can do. Kudos to John Doherty for yet another significant contribution to our science.

Null Space Monte Carlo - Done!

2008-05-01T08:38:00.002-04:00

Groundwater Vistas 5.17 Build 3 contains a working Null Space Monte Carlo procedure. This was developed by John Doherty in Pest Version 11.5. It allows you to calibrate any number of realizations based on the same base calibration. The assumption is that there are lots of parameters in the calibration (preferably pilot points) and that you used SVD-Assist for the calibration. I have tested this in GV for a synthetic 3D model using pilot points for Kx and Kz. While it is a simple model, there were over 400 pilot points and so the characteristics are fairly representative of a real model.

The next step is to work on the post-processing of the calibrated realizations and finally to incorporate this into the Monte Carlo simulation and post-processing that has been in GV for years.

USGS Has Been Busy

2008-05-01T08:29:00.002-04:00

The USGS has released numerous versions of MODFLOW recently. The most recent is an update for MODFLOW2005 (version 1.05.00). The updated the model to the same version as in GSFLOW (described later) and fixed some minor bugs. Most important to me is they added back the DDREFERENCE flag in output control that they removed when going from MODFLOW2000 to MODFLOW2005. That undocumented flag is very nice because it allows drawdown to be computed from the results of any particular time step. If you use Groundwater Vistas, you can access this flag through the new custom output control.

SEAWAT Version 4 was released last month. The major new feature is the ability to simulate heat transport.

The Conduit Flow Process (CFP) was released recently. It allows for the simulation of karst features (conduits) in MODFLOW2005.

GSFLOW is a new surface water/groundwater model. The groundwater part is MODFLOW2005 and the surface water is PRMS (Precipitation-Runoff Modeling System).

None of these new versions are in Groundwater Vistas yet. The new MODFLOW2005 and SEAWAT will be added first, followed by CFP, and finally GSFLOW. The latter will take quite a while to implement.

Null Space Monte Carlo - Almost There!

2008-04-29T10:38:00.002-04:00

The latest version of Groundwater Vistas (5.17 Build 2) now has the Null Space Monte Carlo for PEST Version 11.5 hooked up. If you have the advanced version, you will see it light up now on the Pest menu. I must caution you that it has not been fully tested yet. I am working on that today so there will likely be additional updates by tomorrow as I break and fix things. I am preparing a tutorial on it for my upcoming course in late May. Hopefully everything will work.

I also fixed a couple of bugs related to importing existing models. The first was that GV was not importing the GMG package input file. The second involved not properly recording the layer type codes when importing the HUF package. There was also an odd problem with importing arrays from older vesions of GMS.

New Stuff in Version 5.16 Build 10 to Build 16

2008-04-21T16:27:00.002-04:00

It's been a busy 2 weeks but I have a free minute now to update you on the latest changes in Groundwater Vistas. These are all enhancements (no bugs to report):

- On Model/Pest/Parameters we added several new buttons to make it easier to set up parameters. There is an automated parameter setup, a button to clear all parameters so you can start over, and a button to make all parameters use log transform. For models with lots of parameters, these buttons make it much less tedious to enter all data in the spreadsheet.

- Added the SUPCALC utility to the Model/Pest/SVD Assist menu. This program computes the recommended minimum and maximum number of super parameters when using SVDAPREP.

- Added a restart option on the Pest menu. If you stop a Pest run, this command restarts it either from the last full iteration or from the last model run.

- Added a restart and stop option on the SVD Assist menu for this style of Pest run.

- We have had a few problems with people typing in the path to the working directory under Model/Paths to Models. Some users have entered a trailing "\" character which then causes problems in writing files and running some programs. GV will now look for this and delete it if it is found.

- We added an option under BCs/Delete/Reach that asks if you want to delete the reach in all layers. Before it would only delete in the current layer.

- When importing stream boundary conditions from a text file, we did not have the option to read inflow rates and tributary numbers. You can now import inflow rates and up to 3 tributaries.

You will notice a significant number of changes related to Pest in the coming months, particularly on the SVD Assist and the Null Space Monte Carlo menus. The latter is not yet fit for human consumption but should be working by late May. I plan on covering this topic in my next seminar in Tampa. Those two aspects of Pest are extraordinary and set Pest apart from any other inverse model.

MODFLOW & Vertical Leakance Coefficient

2008-04-07T07:36:00.002-04:00

I seem to get a lot of questions about vertical leakance vs. vertical hydraulic conductivity in MODFLOW. In the original versions of MODFLOW (88 and 96), the Block Centered Flow (BCF) Package required you to enter a value for vertical leakance or VCONT. That value was based on the half-thickness of layers and the vertical K of the layers. All preprocessors that support MODFLOW88/96 compute this for the user, although there are slight differences in how they compute VCONT. Like most preprocessors, Groundwater Vistas computes VCONT based on the saturated thickness of the layer. So as the starting heads change during the evolution of a model, the VCONT may change as well for unconfined layers. However, during any particular simulation, VCONT is constant, even if the saturated thickness of the layer changes.

In MODFLOW2000, the BCF Package is still available with the same assumptions. A new package was introduced that can be used in place of BCF. The new package is the Layer Property Flow Package (LPF). Instead of a vertical leakance, LPF takes as input the vertical hydraulic conductivity directly and computes a vertical conductance internally. The main difference is that it updates vertical leakance at each solver iteration for partically saturated convertible layers. This was a big change and caused many models developed in MODFLOW96 to give different results in MODFLOW2000.

MODFLOW2005 is essentially the same as MODFLOW2000 with one exception. A new option was added that makes LPF more BCF-like. You can choose to have the vertical leakance computed once at the beginning of the simulation and then it remains constant as in BCF.

Which is correct? I think that theoretically the LPF approach is the better one. It is hard to say, though, that all of our older MODFLOW96 models are incorrect. Perhaps with all of the other uncertainties in a model it really does not matter.

On-Line MODFLOW Guide

2008-03-28T08:32:00.003-04:00

With all the versions of MODFLOW coming from the USGS these days, it is hard to keep up with incompatibilities & quirks. This is especially true when using Groundwater Vistas because we support almost all flavors of MODFLOW and most of the new packages and processes. The USGS has an on-line guide that is pretty useful. It has all of the users manuals for the various versions and packages and there is also a stand-alone guide you can put on your computer. It even has a chart of package compatibility. For example, the new UZF (Unsaturated Zone Flow) Package only works with MODFLOW2005 and the GMG (Geometric Multigrid Solver) Package does not work in MODFLOW96. It really pays to read the manuals for each package you are using, especially the really new ones like SFR, HUF, ETS, DRT, etc. Here is the link to the MODFLOW Guide:

http://water.usgs.gov/nrp/gwsoftware/modflow2000/MFDOC/index.html

Better Matrix to Zone Conversion

2008-03-25T07:36:00.002-04:00

I had to convert a bunch of models from GMS to Vistas this week. As many of you know, when you import a model into Vistas, the various properties like hydraulic conductivity are set up as matrices. That means you just get a bunch of numbers instead of a zone database. If you just want to run the model and make minor revisions, this is fine. However, if you want to recalibrate the model or use some other tools in Vistas, you may want that matrix of numbers simplified to a zone database. The only way to do that was to use Props/Options and turn off the use of matrices. Then you had to wait, often many hours, for the conversion to happen.

I set out to make this process more efficient and have reduced the conversion time by many orders of magnitude. So if you get the Version 5.16 Build 9 update, converting properties from matrix to zone is very quick. You also get to choose the number of significant digits used to determine whether two real numbers are equal. This can help simplify a complex matrix.

You may also notice that we skipped from build 6 to build 9 in the most recent blog postings. The intervening builds were just testing new system code schemes.

Recent GV Modifications

2008-03-18T08:02:00.002-04:00

Here are some enhancements and bug fixes for GV Version 5.16 Builds 2 through 6:

- We continue to work on the Pest Null Space Monte Carlo procedures. We hope to have this finished by the time our Advanced Seminar takes place in May.

- We added a new customized telescopic mesh refinement procedure for the Southwest Florida Water Management District. It is called Mine TMR and was designed to analyze the impacts from shallow phosphate mines in Florida. You'll see it under the Grid/Export menu. If you work in Florida and want to use it, contact Robert Peterson at SWFWMD.

- If you used the transient copy for recharge and you had the option selected to save recharge concentrations for all components, only component 1 concentration actually got copied.

- When you run PEST, GV creates a batch file called pestgv.bat that actually runs the model and all necessary pre- and post-processors. If you are using MODFLOW-SURFACT Version 3, depending on the date you purchased it, it might not work with the command line GV writes in the pestgv.bat file. This has been fixed.

- When importing SFR input files under BCs/Import/MODFLOW Package, the SFR unit number got set to zero.

- If the CHD head was equal to the layer bottom, GV was not catching the problem and MODFLOW would quit running with a dry constant head error.

- GV now writes a validation.log file to the gwv5 directory. This is for diagnosing problems with security codes. It is analogous to the hardlock.log file that helps diagnose dongle problems.

MODFLOW Conference

2008-03-18T07:58:00.002-04:00

Just a reminder that the MODFLOW conference will be held at Colorado School of Mines in Golden, Colorado on May 18 to 21. If you have not attended before, it is well worth the trip. Good papers, nice people, great scenery, decent beer. Plus we'll be giving out handy little (1 gigabyte) usb flash drives at our booth. This is the only conference I attend so this is your chance to get inside info and twist my arm for new features!

Jim

PEST Seminar in May

2008-02-29T15:10:00.002-05:00

I have scheduled my next Advanced Groundwater Vistas & Pest course. The seminar will be held May 28-30 at the Residence Inn, Tampa (near the airport).

Originally, my Advanced course had three topics of relatively equal weight: (1) model calibration, (2) uncertainty analysis using monte carlo techniques, and (3) optimization of remedial design and well field management. This evolved into about half the course devoted to model calibration, focusing on Pest, and half on the other 2 topics with a bit of MODFLOW-SURFACT thrown in. The next course will be primarily a PEST course, both from a calibration standpoint and for analysis of uncertainty. Topics will include the basics of calibration, use of Pest in zone-based models, Pilot Point calibration with Pest (including regularization and Singular Value Decomposition), and calibration-constrained monte carlo techniques. I will briefly discuss optimization as well, but probably just half a day.

I will take a maximum of 12 to 14 attendees. The seminar will cost $1,250 per person and you will need to bring a laptop computer.

Go to our web site at www.groundwatermodels.com and click on seminars for more info.

The course is about half full now so don't wait too long if you plan on attending.

A Flurry of Activity

2008-02-29T09:33:00.003-05:00

If you've been following this blog, you'll see we jumped from V5.12 Build 1 to V5.16 Build 1. Here is a summary of what has changed since V5.12 Build 1:

- There was a problem encountered when importing an existing MODFLOW Well package using the option to create Analytic Wells instead of BC Wells. If there were more than 9 wells in a single cell, then the ones beyond 9 were omitted.

- We added an error checking function for Fracture Wells to make sure they do not have a bottom layer that is in a no-flow cell. Turns out that MODFLOW-SURFACT cannot deal with this situation, giving bogus results when this occurs.

- We had to modify our DXF import routine for map files to account for some unexpected things in the Civil CAD program.

- When importing a transient calibration target or analytic well from a text file, you can often get trailing commas on the ends of lines when using Excel. In the past, GV would not import this type of file properly. We added some code to ignore these trailing commas so you no longer have to edit these files in a text editor after generating them from Excel.

- GV has long had a version of MODFLOW96 in double precision. We now added a version of MODFLOW2000 that is also in double-precision. Just go to Model/MODFLOW/Packages and check the double precision flag beneath the MODFLOW version selector. You will notice that the DLL is changed from MF2KWIN32.dll to MF2KDPWIN32.dll. The binary output files from these double-precision versions of MODFLOW are in single-precision so that there are no incompatibility issues with MODPATH and MT3DMS.

- When color flooding matrix properties you can now specify that only cells within the bounds of the matrix are color flooded. A matrix property is one that does not have an associated zone database. For example, bottom elevations are by default a matrix property. You turn properties from zone to matrix using Props/Options. By default, GV will assign blue to the lowest value in the matrix and red to the highest and color flood in between. You can manually change the bounds on a matrix to change what value represents blue and red using Props/Property Values/Manually Reset Matrix Bounds. Normally any value less than the lowest bound would still be blue and any value above the maximum value is red. If you select Props/Options and uncheck the option at the bottom of the dialog, however, then GV will not put a color in these cells that lie beyond the bounds you have established.

- Those of you with good powers of observation will see a new submenu under Model/Pest called Null Space Monte Carlo. This is a powerful feature in Pest where you can generate any number of calibrated models, all with different properties. These calibrated models can then be used to evaluate model uncertainty. This is analogous to the Stochastic part of Groundwater Vistas, which generates realizations that are not necessarily calibrated. In the past, you would need to use "Post Conditioning" to throw out realizations that do not meet some calibration criteria. Anyway, we are in the beginning stages of supporting Null Space Monte Carlo. For now, your menu will be grayed out so you cannot access it. We hope that by late April we will have this finished and those of you with the Advanced or Enterprise versions of Vistas will be able to start using it.

GV Version 5.12 Build 1

2008-02-20T09:53:00.002-05:00

There are three new features added to Groundwater Vistas since Version 5.11 Build 3. Two of these features were requested by one of our users. I point this out because many of you may not realize that you have the power to help shape Groundwater Vistas. If you have an idea for a new option or feature (or modifications to existing tools), just email them to us, along with a clear explanation of what you need. If we agree that the new feature makes sense, then we will add it, often very quickly.

So, here are the new features:

- You can now modify analytic well flow rates for groups of wells automatically using AE/Modify/Well/Flow Rates

- You can have GV set the top of layer 1 in the MODFLOW2000/2005 Discretization Package (DIS) to be the starting heads in layer 1. This can be very handy if you have an unstable model where layer 1 is unconfined but is having dry cell problems. Using this option, you can make all layers confined, thereby making the model stable. Because the water table is the top of layer 1, the transmissivity is then approximately correct. Note that this only applies to MODFLOW2000 and MODFLOW2005. Note also that this option does not carry over to the ET surface or other packages which have the top of layer 1 defined in their own input file.

- The final option goes along with the previous one. There is a new option on the Model/MODFLOW/Package Options - Initial Heads tab, which sets the starting head in dry cells to be a specified height above the layer bottom in that cell. This means that the saturated thickness of all layers will be positive.

GV 5.11 Build 3 and other news

2008-02-11T08:54:00.000-05:00

There are two modifications in GV 5.11 Build 3 released over the weekend:

- We added row and column locations to the analytic well text file export
- When importing a point shapefile for streams, the bottom elevation field was not being activated.

I also received an email last week from Arlen Harbaugh that the USGS intends to put the DDREFERENCE flag in the MODFLOW2005 output control file in the next release (1.5.00 in about a month). This is an obscure but useful feature in MODFLOW2000 that allows drawdown to be computed from the results of any particular time step. When the DDREFERENCE keyword is placed in the output control file (word version only), drawdowns from that point forward are computed based on the results of that time step. Unfortunately it was omitted from MODFLOW2005.

To use this feature in Groundwater Vistas, you select Model/MODFLOW/Package Options - Output Control tab and turn on the use of customized output control, also entering the number of time steps where you would like to save information. Then select Model/MODFLOW/Custom Output Control. There is a column in the spreadsheet for the DDREFERENCE flag (enter 1 to turn it on for a particular time step).

While on this topic, note that MODFLOW-SURFACT Version 3 now also has this flag. We requested that it be added to SURFACT and HGL was kind enough to make that change. At our request, they also added the ability to have steadystate and transient stress periods in the same simulation.

Support for SFR2 and other news

2008-01-31T09:48:00.000-05:00

In Version 5.11 Build 2, we added support for the unsaturated zone flow part of the new SFR2 (Surface Flow Routing 2) in MODFLOW2000 and MODFLOW2005. This feature allows water that infiltrates through the stream bed into the aquifer to be lagged by its flow through the unsaturated zone (where the stream has become disconnected from the water table). You will need four new unsaturated flow parameters on the Stream Boundary Condition dialog in Vistas and there are some new options on Model/MODFLOW2000/Options - SFR tab. By default Vistas will generate SFR1 format files. You must use the SFR tab under MODFLOW2000 options to activate the new SFR2 unsaturated flow conditions.

We also added a new option to post the target value (e.g. head) at the target location instead of residual. This new option is found under Plot/Calibration/Options.

A few bugs have been fixed from V5.10 Build 6 through V5.11 Build 2:
- There was an error in counting CHD cells in TMR models where cells go dry over time at the boundary of the domain. You would know it if you had this problem because the run stops at that point.
- Importing an existing FWL4 input file from MODFLOW-SURFACT into Vistas did not work properly if there were multiple wells in the same cell in the same stress period. Duplicate wells were ignored so pumping was underestimated.

New Groundwatermodels.com

2008-01-18T11:55:00.000-05:00

We just moved www.groundwatermodels.com back to the US from the UK. I know over the years this has been a bit confusing. Environmental Simulations International, Ltd. is a UK company and Environmental Simulations, Inc. is a US company. While we work together, we are separate companies. My brother Doug and I own the US company and are the authors of Groundwater Vistas, AquiferWin32, and Winflow.

We are trying to make the site a lot more useful to our software users. I have to admit that I have not spent a lot of effort on ESI's web presence in the past, but I have decided to focus on it now and you will see a lot of improvements in the near future. Right now we have a one-page shell that directs you to updates and clarifies who we are. In the near future, this will expand to on-line ordering of software, on-line manuals, information on seminars, etc. If you have suggestions, please let me know.

Groundwater Vistas 5.10 Builds 4 & 5

2008-01-17T08:45:00.000-05:00

One minor improvement and one bug to report:

- If you have a lot of boundary conditions (I mean a lot! - like over 100,000), then deleting them can take a long time. Turns out that I did not use the most efficient way of removing these BCs from the list. The new approach in Build 4 and higher takes a process that can take hours in the extreme case to a quick flash of your screen.

- I misinterpreted the HUF Package input instructions, thinking that layer wetting and layer type were entered for the number of huf layers instead of MODFLOW layers. This has been fixed.

GV 5.10 Builds 2 and 3

2008-01-10T09:03:00.000-05:00

Here are a few minor fixes and additions to Groundwater Vistas:

- If you select Props/HSU Options and choose the option to use HSU's (hydrostratigraphic units using Hydrostratigraphy zone numbers) for calibration, then when you get target statistics (Plot/Calibration/Stats) instead of using layer numbers, you use HSU numbers. However, a message warning you about this kicked you back the the main menu so that you never got to see the statistics.

- On the View menu is an option called "automatic refresh". Normally this is on but you can turn it off if you are doing a lot of editing and the screen refresh rate is slow. We now tie this to deleting boundary conditions. Normally GV will draw over the BCs you delete so you can see the progress. In order to speed things up a bit, you can turn off auto refresh and the redrawing of BC cells will not happen until after everything is deleted.

- Targpest utility (used with PEST) was not working when you had flux targets for stream flow and you are using the SFR Package.

- Added a new option on the AE\Modify\Target menu to offset transient head targets. The idea is that for transient calibration you should match change in head rather than the absolute elevation of head at the target. However, if your transient head data do not start at or near the beginning of the simulation period, it is difficult to do this. So if your first head value is off during the calibration, automated methods will focus more on trying to get the heads up or down overall rather than looking at how heads are changing with time. The offset command shifts all head data for transient head targets (with more than 2 measurements) up or down so that the first point matches the current computed head. Now some of you may think this is cheating but it is a valid way of trying to match changes rather than elevations. If you don't agree with this function, just don't use it!

Happy New Year!

2008-01-03T09:07:00.000-05:00

The new year starts quietly...

One minor revision to Groundwater Vistas (Version 5.10 Build 1) - On the BCs/Modify/Simplified Editing dialog, the "replace" option was left off the head modification drop-down list.

My New Year's Wish List...

2007-12-21T09:44:00.000-05:00

- USGS merges all of these different versions of MODFLOW (and various package mismatches) into one universal version (not holding breath on this one)

- New version of SEAWAT2000 with heat transport

- New MODFLOW package for conduit flow (karst)

Rumor has it the last 2 might happen soon.

Happy New Year!

Jim Rumbaugh
Environmental Simulations, Inc.

Groundwater Vistas 5.09 Build 18

2007-12-21T09:42:00.000-05:00

One last update before Christmas...

Vistas was not writing a MODFLOW2000 LPF input file correctly if you had all of the following:
- resaturation active
- more than one unconfined layer
- writing Kx values to external files for use with pilot points in Pest

You would know if you hit this one as MODFLOW would not even run.

MODFLOW Versions and Storage Coefficient

2007-12-19T08:51:00.000-05:00

I have had several emails lately regarding storage coefficients (storage, specific storage, and specific yield) in MODFLOW96, MODFLOW2000, and MODFLOW2005. I thought it was enough to be worth a quick blog...

MODFLOW96 and MODFLOW88 determine which storage coefficient to use based on layer type and comparing the head to the Top of the layer. For layer type 0 (confined), it always uses the storage coefficinet (S). For layer type 1 (unconfined in layer 1), it always uses specific yield (Sy). For layer types 2 and 3, if the head in a cell is above the top of the layer, then it uses S. If the head is below the top of the layer, it uses Sy. This is done on a cell-by-cell basis so that parts of the layer can be confined (S) and part unconfined (Sy).

MODFLOW2000 and MODFLOW2005 only have confined and unconfined layers, like type 0 and type 3 in MODFLOW96 but the principal is the same. However, these MODFLOW versions require you to enter specific storage (Ss). The storage coefficient in a confined layer is then computed for each cell by multiplying Ss by the layer thickness.

Groundwater Vistas does not compute Ss for you if you have S in the storage database. You need to enter the proper values based on the version of MODFLOW you are using. GV will, however, convert from Ss to S for MODFLOW96/88. There is a check-box under Model/MODFLOW/Package Options - BCF tab, that says the storage database contains specific storage (Ss). In this case, GV will multiply Ss by layer thickness for MODFLOW96 and MODFLOW88 BCF Package input.

Clear as mud?

Happy Holidays & Vistas 5.09 Builds 16 to 17

2007-12-19T08:42:00.001-05:00

As you can see, not as many changes over the holidays...

- We added a new import for the Lake Package. This is for a delimited text file containing columns of data under Model/MODFLOW2000/Import Lake Transient Data. The file contains transient data for a single lake. The columns in the file must contain a stress period number and at least one of the following: precipitation, evaporation, withdrawal, runoff. You must also have Vistas set up to use the Lake spreadsheets for data entry. See Model/MODFLOW2000/Options - Lake3 tab.

- A bug was found where Vistas was not generating a proper Pest control file when estimating leakance in zones. This was probably broken during changes made for pilot points and since this type of estimation is rare, it was just recently caught.

- A change was made to allow constant concentration cells with zero concentration value for MODFLOW-SURFACT. Before this change, constant concentration cells with concentration specified at zero were ignored.

Groundwater Vistas 5.09 Build 12 to 15

2007-12-06T15:47:00.000-05:00

A lot of the problems we fixed this week are related to importing existing MODFLOW2000/2005 models. Vistas is really good at this if the files were created by another preprocessor. However, when you get models (typically from the USGS) that were created in text editors, GIS, special programs, or some combination, then there can be problems and we had a bunch of them lately.

- When the GMG solver first came out, there was a memory leak. We reported this to the USGS and they fixed it. But they fixed it in a different way than we did and so there were 2 pieces of code releasing the same block of memory. This did not hurt anything until you tried to make two model runs back-to-back.

- Obscure error when importing a MODFLOW2000 well package that has a non-parameter well and a parameter well in the same cell.

- Another obscure error where boundary condition parameters had different cases in parameter names between the definition of the parameter and the usage of the parameter

... by the way ... When I say "obscure", it means that you are very unlikely to run into it, but some unlucky user did run into it!

- MODFLOW2005 also has the new "highest active layer" option for ET. We had it set for MODFLOW2000 but not MODFLOW2005.

- We recently added the FHB Package to Vistas (not to be confused with the HFB Package). Importing an existing FHB Package input file worked with flux boundaries but there was an error for head boundaries

- When importing an existing Lak3 Package input file for a one-stress period model, the lake precipitation and evaporation values were not being saved properly.

- There was a problem creating the file pestgv.bat for PEST runs using MODFLOW-SURFACT when writing Kz to the BCF input file (instead of leakance) and when the option to maintain vertical anisotropy was also on.

- GV was not correctly recognizing well reach numbers for selecting the decision variables in MODFLOW2000-GWM.

GV 5.09 Build 9 through 11

2007-11-28T16:28:00.000-05:00

Sorry, got behind over Thanksgiving...

Here are a few minor changes for Version 5.09 Build 9 through 11:

- When using Pest with the BCF Package and estimating K in zones for confined layers, there was a problem if not all zones were being estimated. T values were written in that case for the non-estimated zones.

- The ETS Package was not being imported if it showed up in a MODFLOW2000 name file.

- When importing a MODFLOW2000 model with the Well Package that used parameters to define wells, there was a problem if the order of parameter names was not the same as the way they were defined in the start of the file.

- Polygon shapefiles were being recognized by ArcGIS as having errors. Other GIS software did not have a problem. Turns out the vertices were being written counter-clockwise instead of clockwise.

GV 5.09 Build 8

2007-11-14T20:18:00.000-05:00

Several minor modifications for today...

- If you write a run log after doing a "Save As" and changing the name of the Vistas file, the previous Vistas file name was written to the log file.

- When using MODFLOW-SURFACT version 3 with transport, Vistas was not writing the *.con file to the name file.

- The DXF export of particle traces never saved the traces in different colors for different layers if that option was used to display particles within Vistas. Added that to this version.

GV 5.09 Build 7

2007-11-12T12:16:00.001-05:00

We found a bug where the CHD Package was not written correctly in the last stress period if you did not define an extra head for the very last time step (NPER+1) and you did not check the option to make CHD heads constant within each stress period. Because CHD linearly interpolates heads from the beginning of a stress period to the end, you need one extra head value. Anyway, we changed it so that if you do not had that extra head value, then the heads in the last stress period will not be linearly interpolated.

Also, GV does error checking on pilot point location for PEST. Pilot points of the same type cannot be at exactly the same location. GV was not distinguishing between pilot point types though (Kx, Kz, Storage) so if you did have Kx and Kz at the same location then there would be an error in the PEST error/warning file. This did not effect the run.

We discovered that MODFLOW2005 does NOT support the DDREFERENCE option in the output control file (word format only) like MODFLOW2000 does. This is a very handy feature that allows drawdowns after this flag to be computed based on the results of the time step where the flag is entered. We have asked the USGS to add that flag to MODFLOW2005.

MODFLOW2005 V1.4

2007-11-09T08:29:00.000-05:00

MODFLOW2005 Version 1.4 was released on November 2nd. Groundwater Vistas Version 5.09 Build 6 has this new version. Not much really changed but here is what changed:

- Adaptive damping added to the GMG solver (Note that this was added to MODFLOW2000 in Version 1.17.00)
- A new package called SUB-WT (aquifer subsidence in water table aquifers) was added. Groundwater Vistas supports the SUB and IBS compaction packages but not this new one yet.
- A couple of minor fixes in the LAK3 Package

There is still a bug in MODFLOW2005 in the UZF (Unsaturated Zone Flow) Package where the ET rates are not properly exported to the cell-by-cell flow file. Dave Prudic told me that this is fixed but it has not been released yet.

Better HUF Support

2007-11-08T19:11:00.000-05:00

GV 5.09 Build 6

HUF (Hydrogeologic Unit Flow) was a new package added to MODFLOW2000 and MODFLOW2005. It allows you to define hydrostratigraphic layers that are independent of actual model layers. MODFLOW then computes a composite transmissivity based on the HUF layers that intersect each model layer. Not a bad idea.

GV5 supports HUF but the trick is how to get the HUF data into the GUI since GV really only tracks actual model layers. Here are the basic steps you need to follow to use HUF in Groundwater Vistas:

(1) Use Model/MODFLOW2000/Packages and enter a non-zero number next to HUF and check the 2nd column to create it. Put a zero next to LPF to turn that one off and uncheck 2nd column.
(2) select Model/MODFLOW2000/Options - HUF tab. Enter the number of HUF layers you want to use.
(3) add property matrices. This is done using Props/Surface Data. Each "surface" is a 2D matrix in row-column order just like MODFLOW reads it. You will need a matrix of top elevation, thickness, Kx and Kz at a minimum for each HUF layer. You add them by first creating a new one and then using either import or one of the edit commands to fill it.
(4) after adding all of the matrices you need, go to Model/MODFLOW2000/Huf data and select the surfaces for each huf property you need for each huf layer.

So that gets a bit tedious defining those surfaces or arrays. In order to make it easier to use HUF, we added a new export/import. The idea is that you create two GV models. One has the definition of all HUF layers (you don't need boundary conditions or other stuff) and the other has the number of model layers you actually want to use when running MODFLOW. Each must have the same number of rows and columns. You define the HUF model first and then use Props/Export/HUF Data Arrays. Then go into the final model and use Model/MODFLOW2000/HUF Data Import.

New Approach to My Blog

2007-11-08T19:04:00.000-05:00

Well, my first attempt at blogging did not go very far. I guess I am too focused on our software and my consulting and was not able to set aside time for blogging. So now I'm going to use this blog to write about Groundwater Vistas and MODFLOW in general. If you want to keep up with what changes in GV and why, here is where you will find it.

MODFLOW Versions

2006-10-26T07:22:00.000-04:00

For those of you that keep an eye on what the USGS is up to with regards to MODFLOW, you have probably seen a proliferation of MODFLOW versions over the past year or so. It used to be that MODFLOW was a very stable model. From the early 1980's through 1999, there was only one major upgrade (MODFLOW88 to MODFLOW96), although many packages were added by various authors. The next major release was MODFLOW2000, which was significantly more buggy than the previous version. Over the last 2 years MODFLOW2000 has stabilized, just in time for a whole new version - MODFLOW2005 (which was actually released in 2006).

Now, there is nothing wrong with new versions. It is nice to see the USGS actively working on new functionality. The only problem is that authors of new packages and processes are not consistent in terms of which version they base their new code on. Each one uses a different version of MODFLOW2000 or MODFLOW2005 and there is no process in place at the USGS to merge them all into a consistent framework. For example, there are several very interesting new codes on the USGS web page, including:

MODFLOW-VSF - variably-saturated flow - based on MODFLOW2000 V1.15.00
MODFLOW2000-FMP - farm process - based on MODFLOW2000 V1.15.03
MODFLOW-GWM - Groundwater Management (optimization) - based on MF2K V1.13.00
UZF1 Package - unsaturated zone flow - in MODFLOW2005 V1.02
SEAWAT2000 - seawater intrusion - based on MODFLOW2000 V1.15.00

Obviously there is no way to mix options from the various package and versions. And Arlen Harbaugh explained to me that it would not be an easy task to merge all of the versions. This, of course, makes it very hard for software developers and modelers to make sense of it all.

Where were you?

2006-09-11T08:50:00.000-04:00

September 11, 2001 is one of those dates where almost everyone remembers where they were and what they were doing on that terrible morning. A lot of groundwater modelers were either in Golden at the MODFLOW conference or on their way there. I was sitting on an airplane at Dulles International Airport waiting for a mechanical delay to be resolved. Fortunately, we never took off and I eventually made it home with F-16s flying overhead and Northern VA in total grid lock. Just something I'll never forget.

New Groundwater Modeling Blog

2006-09-11T08:44:00.000-04:00

It seems like everyone has a blog these days - the most notorious being the political ones. Well, why not a blog for groundwater modeling? So, here it is. Now, granted, it's going to be slanted towards topics that relate to Groundwater Vistas (the MODFLOW GUI that my brother Doug and I have authored). I'll try to also make it interesting for non-Vistas users, too! I will cover the range of topics from unique applications of models, new tools, new MODFLOW packages, books, etc., etc. You get the idea. Hopefully this will be useful to those of you in the small world of groundwater modeling.