The study defines the hydrogeological framework of the Quaternary aquifer of south Bengal Basin, India, and the impact of urbanisation on the groundwater resources in and around the twin cities of Kolkata-Howrah. The estimated groundwater overdraft in 2016 was 408 × 10³ m³/day, which lowered the piezometric surface by 34 cm. Due to the long-term decline of water levels at the rate of 13–37 cm/year, at some places the piezometric surface occurs below the base of the upper confining bed, generating unconfined conditions. This increases the chance of land subsidence and groundwater quality deterioration. The situation will worsen if the piezometric surface drops further due to over-pumping. The estimated land subsidence for a 1-m drop in the piezometric surface varies between 2.7 and 6.20 cm within the study area. The pre-monsoon groundwater trough represented by the −10 m isopotential line increased from an area of 19 km² in 1985 to 285 km² in 2016. Alarmingly, in just over three decades the area of the trough has increased by 15 times, at an average rate of 8.60 km²/year. The exponential expansion of the groundwater trough and the increased susceptibility of groundwater to hazards are the result of an increase of built-up area from 143 to 243 km² between 1985 and 2016. The urbanization happened mostly in the western part of the study area, which has resulted in the shift of the −10 m isopotential line towards the west and it will further shift in the future.

该研究确定了印度孟加拉南部盆地第四纪含水层的水文地质框架，以及城市化对加尔各答-豪拉两座城市及其周围地区地下水资源的影响。2016年地下水的估计透支量为408×10 ³  m ³/天，使测压表面降低了34厘米。由于水位以13–37厘米/年的速度长期下降，在某些地方，测压表面出现在上侧约束层底部以下，从而产生了无限制条件。这增加了地面沉降和地下水水质恶化的机会。如果由于过度泵送而使测压表面进一步下降，情况将变得更糟。在研究区域内，测压表面下降1 m的地面沉降估计值在2.7至6.20 cm之间变化。等电位线-10 m代表的季风前地下水槽从1985年的19 km ²扩大到285 km ²在2016年。令人震惊的是，在短短的三十年中，水槽的面积增加了15倍，平均速度为8.60 km ² /年。1985年至2016年之间，建筑面积从143 km ²增加到243 km ²，导致地下水槽的指数膨胀和对灾害的敏感性增加。城市化主要发生在研究区域的西部，这导致-10 m等电势线向西偏移，并且将来还会进一步偏移。