Watershed prioritization based on morphometric analysis coupled with multi criteria decision making

Kuttiyadi river basin in the South Indian state of Kerala has been analyzed for planning watershed management activities. Geohydrological behavior of the watershed was analyzed by calculating the morphometric parameters. Linear, relief, and areal parameters were determined using standard equations. Kuttiyadi is a sixth order basin, characterized by maximum relief and gradients in the eastern part, exhibiting highest runoff and susceptibility to flooding and inundation. Relative drainage density data suggest that subwatersheds II and III are mature basins in steady state equilibrium with components like climate, lithology, tectonism, and landscape components. Multi criteria decision making approach was followed for watershed prioritization. Given the interrelationship that exists among the different morphometric parameters as well as the complexity due to the integrated effect of these parameters on soil erosion, analytic network process was employed. Length of overland flow was found to be the most influential morphological parameter in watershed prioritization. High priority subwatershed identified in this study must be taken up for immediate action with respect to soil conservation activities. Suitable locations for construction of check-dams as water conservation structures were identified. This study has shown that morphometric analysis along with multi criteria decision making would serve as a powerful tool in watershed planning where complex interrelationship exists among different morphological parameters.