International Journal of Advanced Engineering Research and Science (IJAERS)
Vol-3, Issue-2 , Feb- 2016] ISSN: 2349-6495
Surface Runoff Estimation using Remote Sensing & GIS based Curve Number Method Ishtiyaq Ahmad, Dr. M. K. Verma Department of Civil Engineering, National Institute of Technology, Raipur, India
Abstract—One of the important components of hydrologic cycle is runoff and influenced by various factors including precipitation and watershed characteristics. Numbers of mathematical models are available to quantify runoff. National Resources Conservation Service (NRSC) has developed a Geographic Information System (GIS) based method known as Soil Conservation Services-Curve Number method (SCS-CN) for computing the runoff depth based on the rainfall depth. This method has universal acceptance as it is simple, predictable and stable method for computing runoff depth. This method is based on one parameter i.e. curve number, which is basically a coefficient that reduces the rainfall to runoff. In the present study SCS-CN method has been applied to estimate the runoff depth in Kharun River basin, a subbasin of Sheonath river in Chhattisgarh state. Various layers has been prepared namely base map, soil map, land use map and other map of the study area using GIS and remote sensing data. Based on the rainfall data of 21 raingauge stations in and around the study area, daily runoff depth has been estimated. Keywords—Curve Number, Hydrologic Soil Group, Geographic Information System, Remote Sensing, Runoff I. INTRODUCTION This study aims to compute the runoff depth using Soil Conservation Service-Curve Number (SCS-CN) method using Remote Sensing and Geographic Information System (GIS). The SCS-CN is a quantitative description of land use / land cover / soil complex characteristics of a watershed. This model is a widely used hydrological model for estimating runoff using runoff and curve number (CN). The CN is an index that represents the watershed runoff potential. In the present study GIS based SCS-CN method is used for estimating the runoff depth in
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the Kharun River Sub-Basin of Sheonath river Basin of Chhattisgarh State of India. The present study reveals that the remote sensing and GIS based SCS-CN can be effectively used to estimate the runoff from the river basins of similar geo-hydrological characteristics.
II.
KHARUN RIVER SUB-BASIN
Kharun River sub-basin a major tributary to Sheonath river in Chhattisgarh State was considered for this study. The study area extends between latitudes 20º32'9.6'' N and 21º39'25''N, and longitudes 81º12'54'' E and 81º58'26'' E. As per GIS total area of Kharun river subbasin is about 4178.33 sq.km. It comprises of Balod (area= 500.19 sq.km.), Dhamtari (area= 593.70898 sq.km.), Raipur (area= 1709.9 sq.km.), Bemetara (area= 327.936 sq.km.)and Durg (area= 1046.6 sq.km.) Districts of Chhattisgarh State. There are about 21 rain gauge stations recording the rainfall data in the study area. Some of the data needed for the study were available from various sources and some of them were procured. The Study area map is shown in Figure 1. The following paragraph gives brief information on the data sources. The Indian Remote Sensing satellite with Linear Imaging Self Scanning sensors (IRS – LISS III) satellite data of scale 1:50000 were collected from Bhuvan portal of Indian Space and Research Organization (ISRO), to use land use/ land cover of the study area. Daily rainfall data for all the 21 rain gauge stations from Water Resources Department Chhattisgarh were used. The soil data from National Bureau of Soil Survey & Land Use Planning (NBSS & LUP). III.
SCS-CN METHOD
Curve Number is basically a coefficient which reduces the rainfall amount. Soil Conservation Services (SCS) CN method is based on two concepts.
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