Evaluation of ground water and land resources in relation to landforms in Alwar District (Rajasthan): A remote sensing based approach

Abstract

Landform and topography of a place determines the recharge and transmission of ground water of a region. In order to evaluate the ground water resources, the ground water potential for the study area was computed from DEM derived parameters like drainage density, slope, parent material, accumulation parameters viz. Compound Topographic Index (CTI), flow accumulation without divergence and geomorphology (landforms). The land potential map ie combined soil and water potential map was generated and the potential under the various landforms has been investigated. The point data on depth to ground water has been spatially interpolated and compared vis a vis ground water potential map of the area generated from the morphometric terrain parameters. Validation of the DEM based ground water potential map with the interpolated ground recharge map shows high R 2 of 0.92. Also comparison was done considering the fractional area of a ground water depth corresponding to a ground water potential under a particular landform class. 95% of the high recharge zones correspond to the transitional landform classes viz. valley bottom and pits category of plains. Alluvial plain and colluvial plain though had high water reserve in the past are presently being depleted at a faster rate. The Poor potential areas occur in parts hilly landforms and occur rarely in plain or transitional landforms (< 5% area). Thus the transitional landforms prove to be the thrust areas where with proper management practices, the land can be brought under cultivation and has scope for cultivation with minimal management options.