A primary use of WMS is to automatically delineate watershed, stream, and sub-basin boundaries from digital elevation sources such as TINs and DEMs. The Drainage module includes all of the commands necessary to perform the automated delineations in preparation of running one of the hydrologic models.
While delineation can be performed using either DEMs or TINs, it is generally easier to use DEMs. In general the DEM method is simpler and more repeatable because of the uniform nature of a DEM data structure. When inadequate elevation resolution is available (i.e. many urban ares) then the feature object method of delineation should be considered.
Some basic guidelines might be:
- DEMs are better for larger, rural watersheds
- TINs might be more appropriate for smaller, urban areas with adequate resolution
- The feature object method works well if no elevation data exist, or if the resolution of the elevation data is not adequate.
Since a DEM or TIN delineation can be converted to feature objects, consider modifying an initial delineation with an elevation source manually with the feature objects. However, understand that some of the parameters computed from the elevation data will be compromised when manual adjustments are made with the feature objects. Be careful and understand what/why modifications are being made.
The Drainage module is included with all paid editions of WMS.
Drainage Module Interface
Several tools and menus are used by the Drainage module. These components are active when the Drainage module is active.
The Drainage module makes use of many of the same tools as the Map module with some differences. See the Drainage Tools article for more information.
The Drainage module makes use of the standard menus, as well as the TIN and DEM menus. The TIN and DEM menus contain commands unique to the Drainage module. See Drainage Module Menus for more information.
When the Drainage module is active, right-clicking on TIN or DEM contain several commands. In the Project Explorer, the Drainage module has the same menus and commands as the Terrain Data module. See Project Explorer Contents for Terrain Data Module for more information.
- Watershed Delineation with DEMs
- Watershed Delineation with TINs
- Watershed Delienation with Feature Objects
- Drainage Coverage
- Drainage Data to Feature Objects
- Drainage Module Feature Objects
WMS – Watershed Modeling System
|Modules:||Terrain Data • Drainage • Map • Hydrologic Modeling • River • GIS • 2D Grid • 2D Scatter|
|Models:||CE-QUAL-W2 • GSSHA • HEC-1 • HEC-HMS • HEC-RAS • HSPF • MODRAT • NSS • OC Hydrograph • OC Rational • Rational • River Tools • Storm Drain • SMPDBK • SWMM • TR-20 • TR-55|
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