Spatiotemporal assessment of pre-monsoon groundwater levels in the Bundelkhand region, India, using statistical techniques

Abstract

The Bundelkhand region of central India represents one of the most critical regions for freshwater availability to meet the water demand of domestic, irrigation and industrial sectors, etc., due to hard rock terrain, erratic rainfall distribution and poor groundwater-bearing formations. The study region has high groundwater level fluctuations, and thus, it is necessary to understand the spatiotemporal variability employing advanced statistical techniques to formulate management strategies for groundwater sustainability. Therefore, the specific objective of the present study was to analyse the district-wise spatial variability and temporal trends of groundwater levels across the Bundelkhand region using long-term groundwater monitoring records and statistical techniques for the Bundelkhand region, India. The study methodology involved autocorrelation analysis, the Mann–Kendall (MK) test, the Hamed–Rao-modified MK test, Sen's slope estimator, anomaly analysis and decadal analysis for analysing groundwater level data of 1996–2023 for the study region. The region comprises 13 districts, out of which 7 districts, viz., Lalitpur, Jhansi, Mahoba, Hamirpur, Jalaun, Banda and Chirakoot, and 6 districts, viz., Datia, Tikamgarh, Chhatarpur, Panna, Sagar, and Damoh, are located in Uttar Pradesh and Madhya Pradesh, respectively. Results showed that the groundwater level fluctuated spatially and Datia recorded the deepest mean groundwater level (MGL) (13.10 m), followed by Chitrakoot (11.52 m) and Jalaun (10.73 m), while Lalitpur (5.52 m), Mahoba (5.77 m) and Jhansi (6.65 m) during the pre-monsoon season. After accounting for serial correlation, significant increases in groundwater depth were identified in Chitrakoot (Sen's slope = 0.158 m year−1), Jalaun (0.102 m year−1) and Datia (0.056 m year−1), indicating groundwater-table decline. Conversely, Jhansi (−0.059 m year−1) and Lalitpur (−0.110 m year−1) exhibited significant decreases in groundwater depth, indicating groundwater-table rise. The anomaly and decadal groundwater level boxplots also revealed the temporal changes in the groundwater level across the Bundelkhand region districts. The results support Sustainable Development Goal-6 (targets 6.4 and 6.5) by providing spatiotemporal evidence of groundwater fluctuation patterns, which may aid in developing strategies for planning sustainable groundwater withdrawal and its management to achieve long-term water security in the Bundelkhand region.