Prediction and Validation of Runoff Through RS and GIS-based Distributed SCS-CN Method Patel Gautam R1,*, Trivedi Mukesh M2,** 1Department of Agricultural Engineering, College of Agriculture, Anand Agricultural University, Vaso, Gujarat 2Polytechnic in Agril. Engineering, Anand Agricultural University, Dahod, Gujarat * email: grpatel@aau.in, gautampatel24@yahoo.co.in
** t.mukesh60@aau.in
Online published on 2 January, 2017. Abstract The runoff curve number (CN), the runoff potential, is a key factor in determining runoff in the SCS (Soil Conservation Service) based hydrologic modelling. The average input based SCS-CN method for calculating the curve number is very tiresome and time consuming in hydrologic modelling. The distributed models require spatial distributed information such as Digital Terrain Model, soil categories, land use, etc. prompting to divide any big catchment into a number of pixels or grids or subgrids and accordingly runoff can be generated over each grid or subgrid. Secondly, the same can be applied to any sub catchment or basin to calculate runoff, even if they are ungauged. The GIS, designed to restore, manipulate, retrieve and display spatial and non-spatial data, is an important tool in analysis of parameters such as landuse/cover, soils, topographical and hydrological conditions. In present study efforts were made to assess the runoff based on lumped CN values to analyze the variation between calculated lumped runoff and runoff calculated by distributed model considering the landuse/cover of the year 2006. It was observed that daily runoff calculated based on lumped data of CN values exhibited more runoff than the runoff calculated based on distributed model at some extent. However, non-significant deviation validatesthe proper assignment of CN valuestorespective grids and hydrologic soil group classes. This paper clearly demonstrated that the integration of GIS with the distributed SCS-CN method provides a powerful tool for estimating runoff volumes in Panam catchment, representing arid to semi-arid catchments of India. Top Keywords Remote Sensing, GIS, distributed SCS-CN method, surface runoff, Panam catchment, arid and semi-arid regions. Top |