CS(AR)-34/98-99 : Representative basin studies: changes in landuse/cover and establishment of SCS runoff curve number for Suddagedda basin, A.P.

Abstract

The landuse/cover are the most important surface characteristics of a basin. They are very dynamic features over space and time and it is difficult to get real time information through conventional means. For economic development of a region/basin, planners need to update knowledge of natural resources, which can be obtained quickly, economically and accurately through only remote sensing technique. Further, the landuse map of a basin/region provides hydrologically significant categories, which are essential prerequisite for estimation of reliable runoff from the basin, especially in ungauged basin.

As a part of representative basin studies, the hydrological landuse/cover mapping has been carried out through visual interpretation for the years December 1987, April 1989, December 1992 and November 1996 using IRS 1B-LISS II, LANDSAT 5-TM and IRS 1C- LISS III data. There is no much significant changes in landuse from the year 1987 to 1996. This landuse/cover maps along with soil map of the basin, the SCS runoff curve number has been established for these years and the same has been used for estimating surface runoff from the basin. Furthermore, the estimated surface runoff is compared with synthetic unit hydrograph method (CWC, 1987). The study reveals that the estimated CN of the basin could be used when there is no adequate hydrological data available.