Spatio-temporal Variation and Trend Analysis of Groundwater Level in Bina and Khurai Blocks of Sagar District, Madhya Pradesh

Groundwater is the primary source of fresh water in the world, including areas with high rainfall and large amount of surface water. Groundwater is the primary source of water supply and an important component of the water cycle as it maintains the flow of rivers during periods of low rainfall. Groundwater levels have fallen sharply due to the increased reliance on groundwater in recent years. Therefore, in order to understand the level of groundwater use and analyse the groundwater scenario such as recharge, discharge etc. in the study area, analysis of groundwater trends is essential. In this study the Mann–Kendall t-test was used to analyze the data collected from the eight hydrological stations located in Bina and Khurai blocks in Sagar district. The monthly GWL data of fifteen observation wells in which twelve wells are dug well and three wells are Piezometric wells of Bina and Khurai blocks for the period 2000–2016 have been used for the study. The minimum and maximum GWL was found to be 0.10 m (bgl) which is 420.6 m above mean sea level (msl) and 27.60 m bgl (429.50 m amsl) respectively. Contour map shows that average GWL vary between 4.07 m and 18.75 m bgl (i.e., 401.18 m to 438.35 m (amsl)) during pre-monsoon and 0.51 m to 16.18 m bgl (i.e., 404.71 m to 440.92 m above msl) during post-monsoon. This analysis investigated the pattern and trends of the daily groundwater level data using Mann–Kendall t-test as means of non-parametric test and parametric Sen’s Slope test on seasonal basis. Pre-monsoon and Post monsoon variations in groundwater trend of Bina and Khurai blocks of Sagar district for 16 years (2000–2016) were analysed using statistical non-parametric tests-the Mann–Kendall (MK) test and Sen’s slope estimator. The Mann–Kendall test indicated falling trends at most wells and rising trends at some wells and at few wells there were no significant trends. Mann–Kendall test showed falling trend was observed in most wells during pre-monsoon and post-monsoon in both blocks signifying overexploitation of groundwater whereas no trend was observed in few wells. Sen’s Slope test was used to identify the significance of the slope and it was seen that declining trend was observed at 95% confidence interval. An average temporal variation of groundwater shows declining trend in Bina and Khurai blocks.