Entropy-based approach for estimation of natural recharge in Kodaganar River basin, Tamil Nadu, India

摘要

An entropy-based approach has been developed for estimation of natural recharge in Kodaganar River basin, Tamil Nadu, southern India. Wells were located in a weathered aquifer which exhibits spatial variability in natural recharge. To determine the fractional amount of rainfall (called natural recharge), marginal entropy and transinformation of rainfall and depth to the water table at selected wells were calculated. Then a ratio of transinformation to marginal entropy of rainfall was used as a measure for assessing natural recharge. The mean natural recharge values at 28 wells distributed over the study area were computed. The average recharge rate was about 62.95 mm/yr or 14.48% of local average seasonal rainfall. The calculated annual input of rainfall to groundwater reserves was about 0.11 x 10(9) m(3)/yr.