Investigations on groundwater levels and consumption in Basanti

Hamdi Abdi Ashur and Mette Nygaard Rasmussen spent July and August 2012 on the island Basanti located in West Bengal, India. During their stay they investigated the variation of the groundwater level in order to determine the validity of a possible decline along with the water consumption and supply. The only source for clean drinking water on the island is groundwater; hence a decreasing trend can indicate unsustainable water consumption.

The manually measured water level and the median values of the water level measured by the Micro Diver indicate that recharge of the aquifer takes place. Furthermore, it was possible to conclude that the aquifers on the island are confined since two impermeable layers overlain the aquifers. The shallow aquifers are saline and only suction hand pumps are used to abstract groundwater from the deep aquifers. Hence, a possible recharge must occur vertically from the mainland. However, it was not possible to determine any general falling or rising trend of the water level, therefore it was neither possible to determine if the water consumption is sustainable. To do so long-term data are necessary.

Previously, a similar project by UBU or IGF in cooperation with JGVK has not been conducted why the project conducted serve as a pilot project for a renewed focus on water resources. The research regarding the water resources on the island will continue along with the data collection from the diver installed.