Quantitative estimation of natural recharge due to monsoon rainfall using the principle of information theory in the area of Ghorawal block of Sonebhadra district, U.P., India

The ground water recharge rate due to monsoon rainfall is estimated for the area of Ghorawal block in Sonebhadra district of Uttar Pradesh (U.P.), India, using the entropy method from the principle of information theory. Average water level measured in ten (10) different locations in Ghorawal block and the monsoon rainfall recorded in the district from year 2007 -2010 was used for the analysis. The contribution due to the monsoon rainfall during this period was obtained by calculating the marginal and mutual entropies of the monsoon rainfall and the depth to water level. A ratio of mutual entropy to marginal entropy of rainfall was used as a measure of the fractional amount of rainfall that recharges the ground water resources in the study area. An estimated rate of 12.1% of the rainfall measured during the study period was calculated.