Rainfall Runoff Modeling Using SCS-CN Method: A GIS Based Case Study of Pawana Watershed

Abstract

In a country over 125 million, we are proudly an agricultural based economy, wherein 51% of population is indulged in any business related to somehow with agriculture. Of course, we still are in a developing stage as far as methodologies or their implementation is concerned. But surely somewhere we have started focusing on modern techniques and strategies to improve pattern, productivity, profit and all. The two vital natural resources required for the agricultural production of any country are soil and water. The net productivity of crops depends on the proper management and utilization of these natural resources. To overcome the water related problems, extensive care should be given to the operation and management of reservoirs and watersheds. Hydrological modelling is a commonly used tool to estimate the basin’s hydrological response to precipitation. It allows to predict the hydrologic response to various watershed management practices and to have a better understanding of the impacts of these practices. This paper highlights a study of lake involving computation of runoff maps and there curve numbers. The selected watershed is been observed for the runoff pattern and the rainfall variations throughout the season. It revealed that, urbanization has led to increase in surface runoff, where as there is decrease in infiltration. This results in increase of surface runoff and contributes more to the natural streams. As a result, the discharge and the surface area of the river increased. These discussed changes seriously lead to water management issues.