Analyzing time series variations in groundwater levels within the Baitarani River Basin, India

Groundwater has been the largest accessible freshwater source globally. The overall dimensions of every basin's water budgeting are closely linked to the quantity quality of available surface and subsurface water. In this paper, the groundwater levels trend in six districts within the Baitarani River Basin, Odisha State, India has been analyzed. Data on the depth to groundwater level for pre and post-monsoon season from 32 wells spread over six different regions from 1997 to 2020 were analyzed. Sen's slope techniques and creative trend analysis were used to investigate the behavior of groundwater level changes in pre- and post-monsoon periods to identify both monotonic and non-monotonic behaviors. The findings showed that, throughout the pre-monsoon and post-monsoon periods, the depth to groundwater level for four Tubewell, five Borewell, and seven Dugwell locations increased. However, only three tubewell stations Champua, Bhadrak, and Karanjia exhibited declining trends in the pre- and post-monsoon periods. In the case of borewell, only one station (Anadapur) has a negative trend in post-monsoon. For Dugwell, during pre-monsoon Banspal represents the –ve trend, and Bhandaripokhari, Banspal, Anandapur, and Joda show negative trends in post-monsoon seasons. A significant decline in groundwater level was observed in three stations for tubewell, one station for borewell, and four stations for dugwell observed in the current study. Accordingly, spatial maps of increasing and decreasing trends of groundwater levels were prepared, which can be used by water resource managers to identify the causes of declining groundwater levels for managing the resources effectively.