Groundwater Flow Direction and Long Term Trend of Water Level of Nadia District, West Bengal: A Statistical Analysis

摘要

Groundwater utilization of Nadia district, West Bengal has been emerging rapidly in the wake of increasing urbanization and production of agricultural commodities and it is, therefore, necessary to evaluate the existing trend and availability of groundwater in time and space for proper planning in near future. Historical groundwater level records, in this respect, provide an important data base for reckoning long term changes in groundwater regime which may be an useful tool for judicious future planning of groundwater utilization. In this perspective, present paper strives to analyze the long term (1984-1998) trend of pre- and post-monsoon water table through the 53 Permanent Hydrograph Stations, maintained by State Water Investigation Directorate, Govt. of West Bengal, distributed all through Nadia district. Statistical analysis shows that, although, most part of the district experiences a declining trend in water table or depletion of groundwater resources in pre-monsoon period to cope up with ongoing demand, the post-monsoon water table shows generally a rising trend of water table i.e. more input of water in the underground aquifer. As the influx of water primarily depends on the replensihment of the aquifer from the prime source of rain water, a correlation of yearly rainfall trend and pre- and post-monsoon water table trend has been made for the specified period and a positive correlation is observed for the district.