The study was taken up as a part of the representative basin studies being done by NIH and involved hydrological land use & land cover mapping for the Suddagedda basin of Andhra Pradesh. Mapping was carried out through visual interpretation for the years December 1987, April 1989, December 1992 and November 1996 using IRS IB-LISS II, LANDSAT 5-TM and IRS IC-LISS III data.

Land use and land 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 on them through conventional means. Planners need to update knowledge of natural resources, which can be obtained quickly, economically and accurately through remote sensing techniques. Further, the land use map of a basin or region provides hydrologically significant categories, which are essential for estimation of reliable runoff from ungauged basins.

There are no significant changes in land use from the year 1987 to 1996 in the basin. The SCS runoff curve number has been established for these years using the land use & land cover maps along with soil map of the basin. The same has been used for estimating the surface runoff from the basin. Furthermore, the estimated surface runoff is compared with the synthetic unit hydrograph method. The study reveals that the estimated Curve Number (CN) of the basin can be used when there is a lack of adequate hydrological data.

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