Abstract
 Identifying Wetland Depressions in Bare-Ground LIDAR for Hydrologic Modeling Track: Water Resources Author(s): Janet Gritzner Processing DEMs for hydrologic modeling generally requires filling of depressions (sinks), features that inhibit surface flow. Majority of sinks are spurious artifacts of DEM creation. Yet some sinks represent real features (i.e., lakes, depressional wetlands, and karst landforms) and should not be filled. To maintain sinks, a threshold grid that identifies real depressions is first generated and, from it, a locate (or seed) mask. Creating a realistic threshold grid requires DEMs that properly resolve topographic depressions, a methodology for sink selection, and data for validation. This paper evaluates bare-ground LIDAR for its ability to resolve surface features in Devils Lake Basin, North Dakota, a region characterized by thousands of shallow, water-filled depressions with sizes ranging from a fraction of an acre to several square miles. It uses National Wetland Inventory (NWI) and Landsat data to aid and validate wetland identification and raster operations to calculate sink depth and area. Janet Gritzner South Dakota State University Geography Box 504 Department of Geography Brookings , SD 57007 US Phone: 605-692-4643 E-mail: janet.gritzner@sdstate.edu |
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