STUDIES ON WELL SPACING AND SELECTION OF PUMPS FOR WELLS IN FRACTURED ROCKS OF KARNATAKA STATE

Abstract

The present study seeks to evaluate the spacing between wells in the hard rock areas of Karnataka, find out and the productivity ;,-. efficiency of the wells, and also assess the suitability of different types of pumps under different conditions. Two approaches have been adopted in evaluating the spacing between wells. One approach makes use of the aquifer parameters of the area, and by means of a computer programme develops a relationship between the radii of influence of pumped wells and their corresponding discharges. By knowing the radius of influence, the spacing which should exist between well can be obtained from a family of curves which relate the spacing between wells, radius of influence and their inter-ference effect. Since the area is a hard rock area, the aquifer parameters have been evaluated by a method which is applicable to heterogeneous formations viz the double porosity model. The second approach uses the ground water recharge data of the area to develop a relation between the spacing between wells and the density of wells and their corresponding dis-charges. It is expected that the radius of influence approach should be used to decide on the actual spacing between wells, and the rainfall recharge method used to decide on the density of wells in an area.