Analysis of groundwater level trend in Jakham River Basin of Southern Rajasthan

Abstract

Groundwater accounts for about half of the water use for irrigation in India. The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells. The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades. This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes, spatially and temporally. Hence, the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique. Rainfall factor was also studied in groundwater level fluctuation during 2009-2019. To analyze the influence of each well during recharge or withdrawal of groundwater, thiessien polygonswere generated from them. In the Jakham River basin, 75 wells have been identified for water level trend study using the Mann-Kendall statistical test. The statistics of trend analysis show that 15% wells are experiencing water level decline in pre-monsoon, while very low percentage of wells have such trend during post-monsoon season. The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon. The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.

Keywords

• groundwater
• trend analysis
• rainfall
• kendal tau
• slope
• p value
• recharge
• pre- and post-monsoon