SPECIFIC YIELD AND ITS RELATION WITH GRAIN SIZE DISTRIBUTION IN QUATERNARY ALLUVIUM OF A PART OF UPPER GANGA BASIN

Abstract

In recent years there has been an increase in ground water utilization activities in the Upper Ganga Basin, namely, the present study area. The shallow aquifers occuring extensively in this area are the most affected. Systematic studies have been initiated and are being continued by the E.P. Ground Water Directorate for estimating available ground water resources for further exploitation. During the course of these studies specific yield values of shallow aquifer material was estimated for a number of samples; and in the present study undertaken an attempt was made with the view of studying various parameters controlling the specific yield of these aquifers. The effect of grainsize distribution on the specific yield besides the effect of time on drainage was also studied. Sieve analysis data of 95 samples were available with U• P. Ground Water Survey Divisions Roorkee which were subjected to graphic statistical analysis for estimating the statistical parameters. Graphic interpretation of specific yield and median phi grain sizes indicated that the specific yield decreases as the median phi particle size increases with increase in inclusive standard deviation; the exact interaction finer particle and its dispersion aspect was further studied by multiple regression, Principal Component Analysis and R--Mode Factor Analysis.