The state of Iowa contains diverse landscapes, each with subtle but impactful differences in their physical characteristics. This data set builds on the previously established landform regions of Iowa (Prior, 2000). All boundaries have been refined based on spatial data sets that become available since Prior (2000). Most importantly, this data set introduces subregions that …Continue reading “Physiographic Regions of Iowa (Shapefile)”
A new approach for delineating noncontributing areas of watersheds is presented. Maps of soil properties offer indicators of subtle landscape features and hydrologic functions. Our approach is to identify soil map units that reflect upland ponding and then define the sum of their watersheds as the noncontributing area. The decrease in time required to delineate noncontributing areas with a GIS method makes it practical to perform regional scale analysis of non-contributing areas.