Hydrogeomorphological Mapping Of Somavathinadi Basin Using Remote Sensing And Gis Techniques, Anantapur District, Andhra Pradesh, India

Anantapur District is a hot and semi arid climate zone, falls in rain shadow zone with a very low annual rainfall of 520 mm. The recurrence of drought increased considerably and unless collective measures are initiated on a permanent basis the situation will become grim in future. Somavathinadi Basin in Anantapur District is selected to demonstrate the capability of high resolution satellite data in Hydrogeomorphology mapping. This Basin is located in Survey of India toposheet Nos. 57F/16, 57J/4, 57G/13 and 57K/01. This Basin with an area of about 452 sq km is underlined by hornblendebiotite gneiss, Granodiorite, closepet granite and by dolerite dykes. Hydrogeomorphological mapping was carried out on 1:10,000 scale using IRS-P6 LISS- IV satellite data. The satellite data facilitates to update the extent of built-up area, road and drainage network. In the basin are digitized, mosaiced and superimposed on hydrogeomorphology map. This helps to give site specific recommendation on ground water prospects In addition; the impact analysis of check dams constructed in the watershed is also discussed. Studies showed that after construction of check dams the water levels in wells increased, abandoned wells got rejuvenated, new bore wells came up resulting increased irrigated area.