Estimation of Curve Number and Runoff in ArcGIS (A Case Study of Meshkin Shahr City)

Flooding is a major natural disaster. This phenomenon becomes more important when it is occurring especially in the city. Therefore, prevention of the communities from the impacts is inevitable. The high level of awareness of potential runoff area for flood management is important. Given this importance, this paper deals with the calculation of runoff with SCS method in Meshkinshahr city and its surrounding area, For this purpose, we used GIS software and the accession of the ARC-HYDRO, especially Arc-CN-RUNOFF software. Finally, the layers of soil hydrologic group, the integration of land use and rainfall averages were compared with the index table, then the resulting map was obtained. Curve number Map (CN), which was proportional to the permeability of the 20 classes. Curve No (32) for areas with high permeability and low runoff and curve number is high (98) for areas with low permeability and high runoff. Dimensional map of the height map is runoff from zero to areas with very high permeability and high runoff starts 99/0, including the use of low permeability to continue. Check the map showed that both CN and RUN-OFF lot to do with the type of the user, so that the use of man-made and synthetic runoff curve number and height are more.