By Lori Armstrong
The World Water Online (WWO) group in the ArcGIS Resource Center has 12 new web map applications based on the SSURGO soil survey database. These apps show soil characteristics that are useful for hydrologic modeling, such as drainage class, available water storage, water table depth, and ponding frequency. The hydrologic group code, which classifies soils based on infiltration rate, can be used to calculate curve number and model how much rain falling in an area will become runoff.
These web applications show how soil properties vary across the landscape and help us understand the nation’s hydrologic regime. And with the launch of Landscape Analyst, we will be exposing the underlying data directly, so that you can use it in your geoprocessing models through web services.
WWO is a collaborative project from the Consortium of Universities for the Advancement of Hydrologic Science Inc. (CUAHSI), the University of Texas at Austin, Esri, and KISTERS. It provides a framework for the contribution and discovery of scientific data across global, regional, and local scales. The ultimate goal of this project is for you to zoom in from a global map to a river located anywhere on earth, and access the best available data for analysis. Web services are in development to enable on-the-fly watershed delineation, and access to real-time observations of precipitation, stream flow, and water quality. You can already try out WWO beta applications to see the map services’ capabilities.