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Determining the direct upland hydrological contribution area of estuarine wetlands using Arc/GIS tools
Citation:
CLINTON, P. J. AND C. L. WEILHOEFER. Determining the direct upland hydrological contribution area of estuarine wetlands using Arc/GIS tools. Presented at Coastal GeoTools, Myrtle Beach, SC, March 02 - 05, 2009.
Impact/Purpose:
The delineation of a polygon layer representing the direct upland runoff contribution to esturine wetland polygons can be a useful tool in estuarine wetland assessment.
Description:
The delineation of a polygon layer representing the direct upland runoff contribution to esturine wetland polygons can be a useful tool in estuarine wetland assessment. However, the traditional methods of watershed delineation using pour points and digital elevation models (DEMs) break down when the pour point is actually a polygon and is often situated at or near zero elevation. Results usually include the entire watershed of the estuary, wildly improbable portions of the entire watershed, or simply the wetland polygon itself. To solve this problem the upland contribution layer was created using available ArcGIS Spatial Analyst and ArcHydro tools. The solution lies in the conversion of zero DEM values to NODATA and the use of the ‘Batch Delineate Watersheds for Polygons’ ArcHydro tool. The layer created was intersected with several raster and vector layers to obtain spatial information about landscape context and anthropogenic parameters that may directly affect the estuarine wetlands. These include the 2001 Multi-Resolution Land Characteristics (MRLC) land cover and impervious surface layers, the Parameter-elevation Regressions on Independent Slopes Model (PRISM) gridded precipitation of annual precipitation for the climatological period 1971-2000 layer, the 2000 U.S. Census block population layer, a degrees slope layer generated from the 10m DEM, 1:24000 roads DLG layer, 1:24000 water courses DLG layer, and the National Pollutant Discharge Elimination System (NPDES) discharge point layer.