The present study aims to trace out the signatures of seawater intrusion into the groundwater and the irrigation hazards in the coastal region of West Bengal, India based on 56 groundwater samples. The result reveals that 48.21 % of the groundwater samples have exhibited the values of seawater mixing index greater than 1 indicating the effect of seawater mixing into the fresh groundwater. The electrical conductivity (EC) in the studied samples ranges from 338 to 4330 $\mathrm{\mu }$S/cm and as per the United States Salinity Laboratory (USSL) classification of EC for irrigation water quality, about 31% of samples come under medium (251–750​ $\mathrm{\mu }$S/cm), 53% under high (751–2250 $\mathrm{\mu }$S/cm), and 16 % under very high (2251–5000 $\mathrm{\mu }$S/cm) salinity hazard classes. Besides, the potential salinity (PS) reveals that about 52 % of samples have high salinity problems while 16 % are moderately suitable (water may be used for medium to coarse-textured soils) and 32 % are suitable which can safely be used for fine and medium, and coarse-textured soils. The problem of salinity intrusion acts as a catalyst to impair agricultural practice. For example, the average yield of rice production is low (1.5–2.0​ t ha⁻¹) for South 24 Parganas compared to the neighbouring districts. The study finds that $\sim$49 % of samples having Na${}^{+}$/Cl${}^{-}$ ratio greater than 1 indicates that silicate weathering is the dominant process controlling groundwater hydro-chemistry and sodium concentration. Moreover, a higher sea-level rise (3.90 ± 0.13 mm a⁻¹) , frequent storm surge (142 events of moderate to severe cyclone during 1582 to 1991) and overexploitation of groundwater and fall of piezometric level (e.g. 10.96 m in 1956–2005 at Gobra, Kolkata) are major driving forces of seawater intrusion.

本研究旨在根据56个地下水样本，追踪海水入侵地下水的特征以及印度西孟加拉邦沿海地区的灌溉危害。结果表明，有48.21％的地下水样品显示出的海水混合指数值大于1，表明海水混合入新鲜地下水中的影响。所研究样品的电导率（EC）为338至4330$\mathrm{\mu }$S / cm和根据美国盐度实验室（USSL）对灌溉水质量EC的分类，大约31％的样品属于中等（251-750 $\mathrm{\mu }$S / cm），高（751–2250）下为53％ $\mathrm{\mu }$S / cm），在很高（2251-5000）时为16％ $\mathrm{\mu }$S / cm）盐度危害等级。此外，潜在的盐度（PS）显示约52％的样品存在高盐度问题，而16％的样品适度适用（水可用于中等至粗糙的土壤），而32％的样品可安全地用于精细盐度测试。中，粗纹理土壤。盐度入侵问题是损害农业实践的催化剂。例如，南部24个帕尔加纳斯的水稻平均产量比邻近地区低（1.5-2.0 t ha ^-1）。研究发现$〜$49％的样品含Na${}^{+}$/氯${}^{-}$比率大于1表示硅酸盐风化是控制地下水水化学和钠浓度的主要过程。此外，更高的海平面上升（3.90±0.13 mm a ^-1），频繁的风暴潮（1582至1991年发生142次中度至严重的气旋事件）以及地下水的过度开采和测压水位下降（例如1956年的10.96 m （2005年在加尔各答的戈布拉市）是海水入侵的主要推动力。