Thursday, January 31, 2008

Support for SFR2 and other news

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.

Friday, January 18, 2008


We just moved 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.

Thursday, January 17, 2008

Groundwater Vistas 5.10 Builds 4 & 5

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.

Thursday, January 10, 2008

GV 5.10 Builds 2 and 3

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!

Thursday, January 03, 2008

Happy New Year!

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.