Interdisciplinary Programme in Climate Studies (IDPCS), Indian Institute of Technology-Bombay, Mumbai, 400076, India.
Rural Data Research and Analysis (RuDRA) Laboratory, Indian Institute of Technology-Bombay, Mumbai, 400076, India.
Environ Sci Pollut Res Int. 2023 Nov;30(52):112548-112563. doi: 10.1007/s11356-023-30158-8. Epub 2023 Oct 14.
Groundwater stored in the aquifers provides water security during natural hazards, e.g. clean water access during floods and droughts. Groundwater drought, a phenomenon closely linked with rainfall (climate) variability, is less researched, especially in India. This study aims to detect precipitation and groundwater droughts and comprehend the groundwater response to long-term precipitation trends (25 years). As a case study, the drought-affected and groundwater-depleted Purulia district in West Bengal, India, which is a part of the Chotanagpur plateau, was selected. Precipitation and groundwater droughts (in aquifer types of shallow, moderate and deep) are detected using the Standard Precipitation Index (SPI) and Groundwater Resilience Index (GRI). During the 25 year study period (1996-2020), Purulia had 13 (52%) rainfall deficiency years, with an annual average rainfall of 1382 mm. SPI detected four severe droughts and the most severe occurring in 2010-2011 (1.50). GRI found that aquifer had a 71% [Formula: see text] conditions and are the most resilient and aquifer experienced maximum extreme drought events and is the most stressed. The cross-correlation coefficients (CCCs) between rainfall and groundwater is moderate in deep, shallow, and medium aquifers, with CCCs - 0.43, - 0.59, and - 0.49, respectively. Positive CCCs are found for seasonal lags of - 3, - 4, and - 7. The study found that during the monsoon, average depth to groundwater level is 1 - 4 m and it drops to 8 - 10 m during the lean period, more than 85% of wells are vulnerable to extreme droughts (SPI > 1.5), aquifer's response to rainfall is aquifer > aquifer > aquifer, and aquifer's may be arranged as aquifer > aquifer > aquifer depending on their drought resistance. This study, with the use of statistical tools and long term data, will aid in the management of groundwater at varying depths by creating basis for understanding the groundwater response to rainfall events.
含水层中储存的地下水在自然灾害期间提供了水安全保障，例如洪水和干旱期间的清洁水供应。地下水干旱是一种与降雨（气候）变化密切相关的现象，特别是在印度，对其研究较少。本研究旨在检测降水和地下水干旱，并了解地下水对长期降水趋势（25 年）的响应。作为一个案例研究，选择了印度西孟加拉邦受干旱影响且地下水资源枯竭的普鲁利亚区，该地区是乔塔那格浦尔高原的一部分。利用标准降水指数（SPI）和地下水弹性指数（GRI）来检测降水和地下水干旱（浅层、中层和深层含水层类型）。在 25 年的研究期间（1996-2020 年），普鲁利亚有 13 年（52%）降雨量不足，年平均降雨量为 1382 毫米。SPI 检测到四次严重干旱，其中最严重的一次发生在 2010-2011 年（1.50）。GRI 发现，含水层有 71%[公式：见正文]条件，具有最强的弹性，且经历了最大的极端干旱事件，因此承受的压力最大。降水和地下水之间的互相关系数（CCCs）在深层、浅层和中层含水层中中等，分别为 0.43、-0.59 和-0.49。在季节性滞后-3、-4 和-7 时发现正 CCCs。研究发现，在季风期间，地下水平均深度为 1-4 米，在淡季期间下降到 8-10 米，超过 85%的水井容易受到极端干旱（SPI>1.5）的影响，含水层对降雨的响应是含水层>含水层>含水层，并且根据其抗旱能力，含水层可能被排列为含水层>含水层>含水层。本研究使用统计工具和长期数据，将有助于管理不同深度的地下水，为了解地下水对降雨事件的响应提供基础。
