ARCH. ENVIRON. SCI. (2011), 5, 37-45 37 Evaluation of ground water and land resources in relation to landforms in Alwar District (Rajasthan): A remote sensing based approach Dipanwita Haldar 1 *, V.K. Sehgal 2 , Gopal Kumar 3 , K.S. Sundara Sarma 2 1 Space Applications Centre (ISRO), Ahmedabad – 380015, India 2 Indian Agricultural Research Institute, New Delhi – 110012, India 3 Central Soil and Water Conservation Research and Training Institute, Vasad, India *To whom correspondences should be addressed E-mail: dipanwita@sac.isro.gov.in Received March 15, 2011. Revised manuscript received July 29, 2011, Accepted August 10, 2011 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 i.e. 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. Keywords: Drainage Density, Ground Water Resources, Ground Water Potential 1. Introduction Land and climatic variability has profound effects on the performance of management systems in improvements of productivity and use of natural resources. In semi-arid environments, much land use depends on water harvesting from the upper members of soil catena to support crops on the lower members. The entire process of water movement depends largely on the elevation of the area (derived terrain parameters), which goes into the process of characterizing the landforms [1]. The relationship for hydrogeomorphology, soil and groundwater prospects is established by Krishna et al. [2] for ecological-economic zoning in Andhra Pradesh. They reported that ground water occurence is influenced by the climate, physiography, drainage and geology of the area. They deduced the ground water potential zones after integration of hydrogeomorphological and lineament maps. The delta, transitional and flood plain are reported to have very good ground water potential followed by pediplains and Bajada and Pediments. The hills and inselbergs have no prospects of ground water. Singh et al. [3] reported that inspite of the stupendous efforts made to develop India’s water resources; optimum benefit could not be attained. The depth to ground water in the delta was reported to be mostly shallow, of moderate depth in the transitional plains and along filled valley. Webb et al. [4] reported well-drained soils occur on steep sunny slopes, imperfectly drained soils occur as a transition between the above two soils. Poorly drained soils occur as a narrow fringe on plain landforms/footslopes/ valley bottom around the bog where water tables are high. Landform analysis and ground water potential in the Bist Doab area, Punjab, India was carried out by Chopra et al. [5]. Ferdowsian et al. [6] reported that the ground water level reduction under Lucerne depend on the landform and ground water flow systems. Gould et al. [7] studied the simulation of