Effect of Monsoon on Groundwater Depth in a Mega City

Abstract

Rainfall infiltration-recharge is one of the most essential component of groundwater recharge. Therefore, better understanding of the physical process of rainfall-recharge through the vadose zone is of fundamental importance for the management of water quantity and quality of groundwater systems. However, quantifying groundwater recharge still remains a challenging task. A GIS-based analysis has been carried out to compare year wise and intermediate changes in seasonal water-level fluctuation in response to pre-monsoon and post-monsoon rainfall obtained from Pilot balloon observatory data as well as NOAA APT data. Furthermore, overall decline rate has been calculated and compared with the previous studies along with the map of zones with declining trend of watertable. The results show monsoon contribution as an important factor but not the only factor. The decline rate is also found to be steepening with time and suggests further deterioration of situation in future.