Estimation of Runoff Using SCS-CN and GIS method in ungauged watershed: A case study of Kharadya mill watershed, India

H.J.Ningaraju, Ganesh Kumar S B , Surendra H J

Watershed, Runoff, SCS-CN, GIS.

Water is the precious gift of nature becoming scarce needs to be conserved. Estimation of runoff in a watershed is very important in order to manage the scarce water resources efficiently. In India the availability of accurate runoff information is rare where most of the watersheds are ungauged, which poses a serious challenge for hydrologists. In this paper Soil Conservation Services Curve Number (SCS-CN) method and the Geographical Information System (GIS) was used for runoff estimation of ungauged Kharadya milli watershed in Mandya district, Karnataka, with an area of 23.95 sq.km. The average annual rainfall is 749 mm from 2003 to 2013. The runoff was varied between 35.47 mm to 240.16mm. The land use details of study area were obtained by integration of GIS and remote sensing. 58.63% of watershed consists of gravelly clay soil and 39.49% area is cultivable crop land. The study reveals that the integration of GIS with the SCS-CN method is a powerful tool for estimating runoff from the ungauged watersheds for better watershed management and conservation purposes.