Evaluation of Lower Errakalava Watershed, West Godavari District, A. P. - An Integrated Approach Using Remote Sensing And GIS Techniques

ABSTRACT The river Yerrakalava, one of the major hydrological systems experiences perennial flooding in the lower part of Lower Yerrakalava watershed, damaging vast extents of Kharif crop and submerging several villages in the upland area of West Godavari district, Andhra Pradesh during monsoon season. The flooding menace has continued despite the regulation of heavy flows in the river and its tributary systems by construction of medium irrigation projects such as Jalleru and Yerrakalava in the Upper Yerrakalava watershed. Moreover, man-made interventions to the flow patterns, the flooding is mainly attributed to the physiographical set-up, geological and geomorphological processes and various other terrain elements that have direct bearing on the geometry of the watershed particularly in the lower part. A geo-scientific attempt which includes geo-spatial technologies has been made in the present study to evaluate various natural resource parameters in the Lower Yerrakalava watershed and ascertain the scientific reasoning of flooding. The study also provided suitable and lasting solutions to avert the perennial flooding in this area. Keywords: Watershed, Geomorphology, Structure, Flood menace, water resources