Morphometric assessment and sub-watershed prioritization of Khari River basin in semi-arid region of Rajasthan, India

Abstract

Watershed management is very crucial for arid and semi-arid regions dealing with limited availability of water resource. Morphometric assessment and prioritization studies provide basic criterion for effective local level watershed planning and natural resource management. The present study is an attempt to analyze morphometric characters of the Khari River basin and prioritize the sub-watersheds on the basis of ground water potentialities indicated by morphometric parameters using GIS approach. Khari River is semi-arid ephemeral; it is a tributary of Banas River, an important river of central Rajasthan (India). The basin has been subdivided in five sub-watersheds namely SW1 to SW5. Linear, areal, and relief parameters are calculated for Khari basin as well as for each sub-watershed. Morphometric parameters that are related to groundwater potentialities are ranked and compound factor values are calculated for each sub-watershed and priority is allotted based on these values. First priority is given to the least value of compound factor that indicate most deficit ground water condition. Overall results illustrate that Khari is a sixth-order stream and covers 6205 km2 area. Dendritic pattern is observed in Khari and in all the five sub-watersheds that indicate homogenous nature of underlain material and less structural control in the topography. Presence of low bifurcation ratio, low drainage density, and low drainage frequency values are favorable parameters of good permeability, infiltration in the basin, further gentle slope, coarse drainage texture, moderate to low relief, and elongated shape—all these parameters indicate good groundwater potentialities in major portions of the basin. Prioritization results show that the sub-watershed SW4 is at first priority with most deficit groundwater potential in comparison to other sub-watersheds and require water conservation measures. Sub-watershed SW4 has high values in linear parameters and low value in shape parameters that specify for poor groundwater potential, less permeability and high runoff, etc. Sub-watershed SW5 on contrary has indicated highest ground water potential in comparison to other sub-watersheds of the basin. The study provide local drainage morphometric information and preliminary prioritization for better water resource management in semi-arid region to achieve water self-sufficiency and sustainability at basin level.