Groundwater in the coastal districts of West Bengal, India is highly susceptible to various factors such as over-pumping, variations in rainfall, lower elevation and risk due to sea level rise. In addition to these factors, tropical cyclone induced storm surge and saltwater intrusion also induce potential risks to the quality of the coastal aquifers. There are several knowledge gaps, as many of these factors have not previously been systematically and rigorously analysed; furthermore, up-to-date information is either unavailable or insufficient. Accordingly, the present study analysed the groundwater vulnerability during the pre- and post-monsoon months for the period from 2001 to 2010 at three main coastal districts of West Bengal: East Midnapore, South 24 Parganas and North 24 Parganas (administrative regions). The GALDIT index-based model was employed to assess salt-water intrusion into the groundwater using Geographic Information System (GIS). Spatial distribution maps were also generated to identify highly vulnerable groundwater locations. Map removal and single parameter sensitivity analyses were performed to understand the sensitivity of the parameters. The study reveals that the depth of ground-water levels for the three districts increased and also the rainfall exerts a significant effect on the groundwater depth. The chemical constituents TDS and chloride contents in groundwater during the period 2004 to 2010 were analysed. The average TDS range values for pre- and post-monsoon seasons were observed to vary in the range between 100 and 3874 mg/l and 83–1929 mg/l respectively. Reports indicate that, groundwater in the area is highly saturated with iron containing minerals like Fe(OH)3, goethite, and hematite and is also moderately saturated with the calcite, chalcedony, dolomite and quartz, whereas under-saturated with anhydrite and gypsum. The implications of the research points to the urgent need for remedial action and appropriate responses at policy-level to protect groundwater.

印度西孟加拉邦沿海地区的地下水极易受到各种因素的影响，例如过度抽水，降雨变化，海拔降低以及海平面上升带来的风险。除了这些因素外，热带气旋引起的风暴潮和盐水入侵也对沿海含水层的质量造成潜在的风险。存在许多知识鸿沟，因为以前尚未对这些因素中的许多因素进行过系统和严格的分析。此外，最新信息不可用或不足。因此，本研究分析了2001年至2010年季风前后前后西孟加拉邦三个主要沿海地区的地下水脆弱性：东米德纳坡，南24帕尔加纳斯和北24帕尔加纳斯（行政区）。使用基于GALDIT指数的模型，使用地理信息系统（GIS）评估盐水对地下水的入侵。还绘制了空间分布图以识别高度脆弱的地下水位置。进行了地图去除和单参数敏感性分析，以了解参数的敏感性。研究表明，这三个地区的地下水位深度都增加了，降雨对地下水位也有显着影响。分析了2004年至2010年期间地下水中的化学成分TDS和氯化物含量。季风前后季节的平均TDS范围值分别在100和3874 mg / l和83-1929 mg / l之间变化。报告表明，该地区的地下水被铁（Fe（OH）3），针铁矿和赤铁矿等含铁矿物质高度饱和，方解石，玉髓，白云石和石英也被中度饱和，而硬石膏和石膏则不饱和。研究的意义表明，迫切需要采取补救措施并在政策一级采取适当对策以保护地下水。