Study of the Impact of Land Use Change on Estimation of Runoff Using SCS-CN & GIS for Gangua-Jhumka Water Shed

Abstract

Due to increasing demand for basic human needs and welfare of ever growing population there is seen remarkable changes in land use land cover of particular areas. Land use land cover has become a important component in current strategies for managing natural resource and managing environmental changes in present days. The objectives of this research were to analyse the land use land cover change for two periods 2005-06 and 2011-12 and comparing the changes, to study the impact of LULC change on runoff and to estimate the runoff of a watershed area i.e. Gangua Jhumka watershed. Accurate estimation of runoff is an important work for proper watershed management. Direct runoff of a catchment is depended on soil type, and cover and rainfall. Among all the methods available for estimation of runoff SCS-CN method is the most popular. The curve number depends on soil and land use characteristics. This study was carried out in Gangua Jhumka watershed located Khurdha District of Odisha using remote sensing and GIS. The total area of watershed 685.711 sq. km. Soil map, Land use map, elevation maps are generated from GIS Environment. In this research work as the study area is a fast developing city and the population growth is remarkable so most of the agricultural land and forest lands are converted to built up lands. Land sat satellite image was used to obtain land cover information. The thematic maps like soil map, elevation map, and land cover map were created in Arc GIS 10.3. Curve numbers are assigned for different land cover and soil types. In present study the runoff calculated are 1307.6 mm and 1434.8 mm for the year 2005-06 and 2011-12 respectively. Due to increase urbanization runoff has decreased in the study area.