Determination of deep tubewell spacing using aquifer characteristics an irrigation requirement

Abstract

Relationship between deep tube well spacing in square grid tube well layout ?nd aquifer characteristics has been studied using unsteady ground water flow equations. Both constant discharge and variable discharge conditions were considered and unsteady ground water flow equations were solved with the help of an IBM 360 digital computer. Comparison was made between spacing of wells subjected to mutual interference and spacing of wells without interference. Discharge coefficient of transmissibility, storage coefficient, time of pumping, static lift and peak monthly irrigation water requirement has been used as variable parameters. The storage coefficient should be the determining factor in selecting deep tube well spacing when aquifer characteristics are considered. Some amount of mutual interference is allowable in selecting deep tube well spacing and non-interference spacing is not always practicable. It is not important to consider the variability of well discharge due to increase in drawdown at the well with time. A design chart has been developed for the selection of deep tube well spacing considering aquifer characteristics and irrigation water requirement, in square 'grid tube well layout.