Models with GRASS

  I see that there are choices for hydrologic and erosion models
incorporated within GRASS. From the descriptions, I learn that most of the
erosion models (and many of the runoff models) were developed in
agricultural areas for agricultural drainages and situations. We don't work
with agricultural clients, so I'm looking for insight on which models would
be best for us to learn and use.

  The SWAT model looks like a keeper. It handles large areas and long time
periods. I can see a number of applications with large mine permitting,
compliance monitoring and reclamation for this model. It will model both
water and erosion potential.

  But, we also have a need for a runoff model for discrete events (say, a
24-hour, 10-year storm event). Such a storm event is appropriate for the
high desert and Great Basin geographic regions, but not for the temperate
rain forest found west of the Cascade mountains in the upper left corner of
the US. For this area (where a "storm event" can last a week or two) we need
both a discrete-event model (to satisfy regulatory agency requirements) and
a continuous-event model on a fine scale to satisfy mine planning
requirements. We also need a sediment transport model for rivers and streams
to complement the erosion models for the upland portions of the drainage
basin.

  I'd like to hear from those of you with experience on these models and any
others that are not listed on the web site (e.g., groundwater, pollution,
animal population).

TIA,

Rich

Dr. Richard B. Shepard, President

                       Applied Ecosystem Services, Inc. (TM)
              Making environmentally-responsible mining happen. (SM)
                       --------------------------------
            2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
+ 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard@appl-ecosys.com

Hi Rich,

Yep, SWAT is the hands-down best hydrologic model out there.
(not that I'm biased or anything). As you said, it handles watersheds
from field size up thousands of square miles. It is our favorite here
because of its versatility. We've used it for single events as well as
very long term simulations. SWAT handles erosion and sediment transport,
nutrient transport as well as pesticide fate and crop growth. so it should
fit the bill for you.

While the model is ARS, we work closely with them and maintain
a comprehensive information/download site. The address is:
http://www.baylor.edu/~cagsr/swat

When I was working on the HUMUS project, SWAT was used
to simulate the entire US in single model runs because it can handle
multiple basins along with the routing. I think we validated the model
with an r^2 or .95. So it's very reliable. The GRASS GIS interface
makes model input development very easy.

Feel free to shoot me any questions you may have.

Bruce

--
Bruce Byars
GRASS Dev. Team
CAGSR - Baylor Univ.

Rich Shepard wrote:

  I see that there are choices for hydrologic and erosion models
incorporated within GRASS. From the descriptions, I learn that most of the
erosion models (and many of the runoff models) were developed in
agricultural areas for agricultural drainages and situations. We don't work
with agricultural clients, so I'm looking for insight on which models would
be best for us to learn and use.

  The SWAT model looks like a keeper. It handles large areas and long time
periods. I can see a number of applications with large mine permitting,
compliance monitoring and reclamation for this model. It will model both
water and erosion potential.

  But, we also have a need for a runoff model for discrete events (say, a
24-hour, 10-year storm event). Such a storm event is appropriate for the
high desert and Great Basin geographic regions, but not for the temperate
rain forest found west of the Cascade mountains in the upper left corner of
the US. For this area (where a "storm event" can last a week or two) we need
both a discrete-event model (to satisfy regulatory agency requirements) and
a continuous-event model on a fine scale to satisfy mine planning
requirements. We also need a sediment transport model for rivers and streams
to complement the erosion models for the upland portions of the drainage
basin.

  I'd like to hear from those of you with experience on these models and any
others that are not listed on the web site (e.g., groundwater, pollution,
animal population).

TIA,

Rich

Dr. Richard B. Shepard, President

                       Applied Ecosystem Services, Inc. (TM)
              Making environmentally-responsible mining happen. (SM)
                       --------------------------------
            2404 SW 22nd Street | Troutdale, OR 97060-1247 | U.S.A.
+ 1 503-667-4517 (voice) | + 1 503-667-8863 (fax) | rshepard@appl-ecosys.com