ESTIMATION OF RAINFALL RUNOFF USING SCS-CN AND GIS APPROACH IN PUZHAL WATERSHED

Rainfall runoff is one of the important hydrological variables in determining land and water resources application. Curve Number method is widely used and efficient method to estimate the infiltration characteristic of the watershed in accordance with the land use/land cover property and soil property. In this study to estimate the rainfall runoff modeling in this study area with an area of 152.81 sq km using Soil Conservation Service Curve Number (SCS-CN) method and GIS. The estimated amount average annual rainfall 1322.29mm from 1999 to 2013.The runoff varied from 285 mm–4053mm, which is corresponds to 61.6% of annual average rainfall of Thiruvalur district. These details are used for better watershed management and conservation purpose.