Comparison of Arc Hydro and SWAT models used in watershed analysis
Abstract
This project examined the applicability of two of the most
common models used in hydrological modeling today: ArcHydro (ArcGIS
Hydro Data Model) and SWAT (Soil and Water Assessment Tool) model.
The models are similar in that each advertises itself as a
watershed model with an interface to GlS. The models differ in
their choice of governing equations and the way each deals with
actual data that may be collected in the watershed. The purpose of
the proposed research was to determine which model provided the
best representation of a watershed. Data was collected for the
Blanco and Guadalupe watersheds and imported into each model. Once
the models were run, the results were compared to actual field data
to test the accuracy of the models and ease of use. Both models
permitted us to simultaneously study various parameters acting on
the watersheds. The SWAT model allowed the researchers to
incorporate more physical data than the ArcHydro model, resulting
in a more accurate depiction of the watershed, especially for
smaller watersheds like the Blanco. ArcHydro excels at data
management, making it a better choice when large amounts of data
need to be collected and included in the model (such as with larger
watersheds like the Guadalupe). We found that SWAT better
replicates field information. In addition, it allows the researcher
more control over the physical processes being modeled. SWAT is
easier to use for researchers with little GIS experience. However,
for those researchers with GIS programming capabilities, ArcHydro
is more flexible.