In recent years, groundwater pollution has become increasingly a serious environmental problem throughout the world due to increasing dependency on it for various purposes. The Damodar Fan Delta is one of the agriculture-dominated areas in West Bengal especially for rice cultivation and it has a serious constraint regarding groundwater quantity and quality. The present study aims to evaluate the groundwater quality parameters and spatial variation of groundwater quality index (GWQI) for 2019 using the fuzzy analytic hierarchy process (FAHP) method. The 12 water quality parameters such as pH, TDS, iron (Fe⁻) and fluoride (F⁻), major anions (SO₄²⁻, Cl⁻, NO₃⁻, and HCO₃⁻), and cations (Na⁺, Ca²⁺, Mg²⁺, and K⁺) for the 29 sample wells of the study area were used for constructing the GWQI. This study used the FAHP method to define the weights of the different parameters for the GWQI. The results reveal that the bicarbonate content of 51% of sample wells exceeds the acceptable limit of drinking water, which is maximum in the study area. Furthermore, higher concentrations of TDS, pH, fluoride, chloride, calcium, magnesium, and sodium are found in few locations while nitrate and sulfate contents of all sample wells fall under the acceptable limits. The result shows that 13.79% of the samples are excellent, 68.97% of the samples are very good, 13.79% of the samples are poor, and 3.45% of the samples are very poor for drinking purposes. Moreover, it is observed that very poor quality water samples are located in the eastern part and the poor water wells are located in the northwestern and eastern part while excellent water quality wells are located in the western and central part of the study area. The understanding of the groundwater quality can help the policymakers for the proper management of water resources in the study area.

近年来，由于各种目的对地下水的依赖日益增加，地下水污染已成为世界范围内日益严重的环境问题。达莫达尔扇三角洲是西孟加拉邦以农业为主的地区之一，尤其以水稻种植为主，地下水量和水质受到严重制约。本研究旨在使用模糊层次分析法（FAHP）评估2019年地下水质量指标（GWQI）的地下水质量参数和空间变化。12 个水质参数，如 pH、TDS、铁 (Fe ^- ) 和氟化物 (F ^- )、主要阴离子（SO ₄ ^2-、Cl ^-、NO ₃ ^-和 HCO ₃⁻ ) 和阳离子（Na ⁺、Ca ²⁺、Mg ²⁺和 K ⁺)对研究区的29口样井用于构建GWQI。本研究使用 FAHP 方法来定义 GWQI 不同参数的权重。结果表明，51%的样井碳酸氢盐含量超过了饮用水的可接受限度，在研究区是最高的。此外，在少数位置发现了较高浓度的 TDS、pH、氟化物、氯化物、钙、镁和钠，而所有样品井的硝酸盐和硫酸盐含量均在可接受的范围内。结果显示，13.79%的样本是优秀的，68.97%的样本非常好，13.79%的样本很差，3.45%的样本在饮用方面很差。而且，据观察，极差水质水样位于东部，不良水井位于西北和东部，优良水质井位于研究区西部和中部。对地下水水质的了解有助于决策者对研究区的水资源进行适当的管理。