Abstract Groundwater is considered the purest form of water on Earth, replenished through rainfall and seepage from surface water. Purba Medinipur, a significant district in West Bengal, is crucial for irrigation, tourism, and industry. Therefore, it is essential to assess trends in groundwater, which is vital for all these sectors, along with conducting geomorphological and climatological analyses that influence groundwater levels. In a tropical country like India, the annual rainfall in Purba Medinipur has varied from 1167 mm in 2015 to 2275 mm in 2021, surpassing levels recorded in other parts of West Bengal. Pre-monsoon rainfall is typically higher than post-monsoon rainfall in the coastal region. The frequency of maximum 1-day rainfall shows a mixed trend from 2010 to 2022, displaying an upward trend since 2021. However, before that, it was mostly declining. Due to the variability in rainfall and anthropogenic activities, groundwater levels in the study area have declined by 6.11% during the pre-monsoon and 7.36% during the post-monsoon period annually. It is important to evaluate the trend of rainfall data from the Centre for Hydrometeorology and Remote Sensing, as well as groundwater level data collected from the Central Groundwater Board. Over a long period, the average rainfall in the study area was 889.92 mm. Both pre-monsoon and post-monsoon precipitation decreased from 2010 to 2022, with the frequency of maximum monsoon rainfall observed in September. Various statistical methods, including the Mann–Kendall test, p-value analysis, alpha, and Sen’s slope estimator, have been employed in this study. These methods reveal a negative trend in rainfall magnitude, while groundwater levels have shown a steady trend. To enhance groundwater levels, in addition to natural rainfall recharge, implementing artificial rainwater harvesting measures is recommended in the study area. Research highlights <UnorderedList Mark="Bullet"> <ItemContent> Annual rainfall in the study area varied from 1167-2275 mm during 2010–2022, while groundwater levels (GWLs) declined annually by 6.11% in pre-monsoon and 7.36% in post-monsoon. These emphasize the need to assess the relationship between groundwater dynamics and meteorological factors. </ItemContent> <ItemContent> Rainfall variability was analyzed using GIS-based non-parametric statistical methods, classifying La Nina, Neutral, and El Nino phases and evaluating their effects on GWLs alongside LULC changes. </ItemContent> <ItemContent> Relationships among GWLs, rainfall, and human activities were mostly linear. Future GWLs were projected through regression models, recommending managed aquifer recharge as a sustainable strategy to mitigate GWL decline. </ItemContent> </UnorderedList>

Assessment of interrelationship of rainfall variation with groundwater level shift based on statistical measures in Purba Medinipur, India

期刊论文
发表日期：

2026年5月4日

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Souvik Chakraborty,
Subhasish Das

摘要

Abstract

Groundwater is considered the purest form of water on Earth, replenished through rainfall and seepage from surface water. Purba Medinipur, a significant district in West Bengal, is crucial for irrigation, tourism, and industry. Therefore, it is essential to assess trends in groundwater, which is vital for all these sectors, along with conducting geomorphological and climatological analyses that influence groundwater levels. In a tropical country like India, the annual rainfall in Purba Medinipur has varied from 1167 mm in 2015 to 2275 mm in 2021, surpassing levels recorded in other parts of West Bengal. Pre-monsoon rainfall is typically higher than post-monsoon rainfall in the coastal region. The frequency of maximum 1-day rainfall shows a mixed trend from 2010 to 2022, displaying an upward trend since 2021. However, before that, it was mostly declining. Due to the variability in rainfall and anthropogenic activities, groundwater levels in the study area have declined by 6.11% during the pre-monsoon and 7.36% during the post-monsoon period annually. It is important to evaluate the trend of rainfall data from the Centre for Hydrometeorology and Remote Sensing, as well as groundwater level data collected from the Central Groundwater Board. Over a long period, the average rainfall in the study area was 889.92 mm. Both pre-monsoon and post-monsoon precipitation decreased from 2010 to 2022, with the frequency of maximum monsoon rainfall observed in September. Various statistical methods, including the Mann–Kendall test, p-value analysis, alpha, and Sen’s slope estimator, have been employed in this study. These methods reveal a negative trend in rainfall magnitude, while groundwater levels have shown a steady trend. To enhance groundwater levels, in addition to natural rainfall recharge, implementing artificial rainwater harvesting measures is recommended in the study area.

Research highlights

Annual rainfall in the study area varied from 1167-2275 mm during 2010–2022, while groundwater levels (GWLs) declined annually by 6.11% in pre-monsoon and 7.36% in post-monsoon. These emphasize the need to assess the relationship between groundwater dynamics and meteorological factors.

Rainfall variability was analyzed using GIS-based non-parametric statistical methods, classifying La Nina, Neutral, and El Nino phases and evaluating their effects on GWLs alongside LULC changes.

Relationships among GWLs, rainfall, and human activities were mostly linear. Future GWLs were projected through regression models, recommending managed aquifer recharge as a sustainable strategy to mitigate GWL decline.