Hydrological evaluation of Koraiyar watershed by morphometric analysis

Abstract

Morphometric analysis was conducted in Koraiyar watershed which lies in Walyar sub basin of Parambikulam Aliyar Project (PAP). It is in the over exploited groundwater extraction category. The quantitative morphometric analysis was carried out in 24 micro-watersheds of Koraiyar watershed using GIS technique for determining the linear aspects such as stream order, bifurcation ratio, stream length and aerialaspects such as drainage density, stream frequency, form factor, circulatory ratio, and elongationratio. Prioritization based on different morphometric parameters was done. The morphometric analysis of different micro-watersheds showed their relative characteristics with respect to hydrologic response of the watershed. Results of morphometric analysis show that micro-watersheds 5, 7, 13, 19, 21 and 23 are possibly having high erosion problems. Hence, suitablesoil erosion control measures are required in these micro watersheds to preserve the land from further erosion.