Spatio-temporal analysis of precipitation dynamics and groundwater recharge trends in Jharkhand, india: implications for water resource management

Abstract

Understanding regional hydroclimatic patterns is essential for managing water resources and ensuring agricultural sustainability in rain-fed areas under changing climate conditions. The intensifying effects of climate change on rain-fed agriculture in India necessitate a comprehensive understanding of the precipitation dynamics and groundwater recharge patterns. This study strives to evaluate the relationship in 11 districts of Jharkhand between 2001 and 2020 using rainfall and ground water level data collected from Indian Meteorological Department (IMD) and Central Ground Water Board (CGWB), Ranchi respectively. Rainfall data analysis reveals significantly positive and negative trends in pre-monsoon, monsoon, and post-monsoon across districts. Pre-monsoon rainfall ranged from 25 to 175 mm, monsoon from 650 to 1250 mm, and post-monsoon from 20 to 120 mm, with higher values in Simdega, Lohardaga, and Latehar, and lower values in Garhwa and Palamu. The Mann-Kendall test indicated negative rainfall trends in 7 out of 11 districts, with Sen’s slope values declining up to − 6.8 mm/year, especially in eastern and northern Jharkhand. Pre-monsoon groundwater levels varied between 2 and 18 m, with declining trends in Palamu, East Singhbhum, and Khunti, while positive trends (Sen’s slope up to 0.21 m/year) were observed in Simdega and Ranchi. In the post-monsoon period, six districts such as Simdega, Latehar, Gumla, Ranchi, West Singhbhum, and Saraikela Kharsawan, exhibited positive trends, whereas Garhwa and East Singhbhum showed declines of − 0.12 to − 0.17 m/year. Addressing these hydroclimatic challenges in Jharkhand requires region-specific strategies, such as rainwater harvesting, efficient irrigation methods, and localized groundwater management to mitigate water stress, sustain agriculture, and enhance resilience to climate variability.