Abstract
 A New Curve Number Calculation Method Using GIS Technology Track: Water Resources Author(s): Allen Xu Runoff Curve Number is a key factor in determining runoff in the hydrologic modeling based on the SCS (Soil Conservation Service) runoff Curve Number (CN) method. The traditional method to calculate the weighted CN is very tedious, which takes up a major portion of hydrologic modeling time. CN is a function of soil type and land use. With the GIS, formatted soil and land-use data are becoming increasingly available from the public domain. This paper introduces data retrieving and processing using ArcGIS 9.1. After overlaying the soil survey data polygon, drainage subbasin polygon and land-use polygon, a new intersection shapefile can be created as a base file for the CN calculation. The technique to convert SSURGO soil data into hydrologic group and the method to calculate the weighted CN based on the polygon's land-use category are also described. The CN calculation using this method can be dramatically simplified. Allen Xu Parsons Brickerhoff 2777 Stemmons Frwy Suite 1333 Dallas , TX 75207 US Phone: 214-8195973 E-mail: xual@pbworld.com |
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