Analyzing the Influence of Land Use Land Cover Dynamics on Groundwater Reserves in Mymensingh Sadar Region through Remote Sensing and GIS Techniques

Land use land cover (LULC) changes have been occurring at a fast pace in places like Mymensingh Sadar in Bangladesh, where these changes are mainly due to urbanization and agricultural expansion. These changes are a major reason for the depletion of groundwater in such densely populated deltaic regions. The remote sensing (Landsat 8-9 OLI/TIRS) and GIS tools were used in this study to look into the LULC changes of the area (2017-2023) by performing semi-supervised hybrid classification, and to determine the groundwater trends by applying inverse distance weighting interpolation. The methodology was confirmed with NDVI-derived vegetation health indices and accuracy assessments (overall accuracy: 82.35%) that were quite robust. The analysis showed that urban areas grew by 96.6%, which was related to population increase (72%) and water demand increase (66%). At the same time, the expanse of farmland was reduced by 16.65%, which in turn resulted in water use for irrigation being reduced by 24.16%. Groundwater depletion was aggravated such that the water table went down from 5.5 to 12.19 m in 2017 and 10.8 to 15.13 m in 2023, which is a 40-60% decline in aquifer levels. Though weak, there was a negative correlation between NDVI and groundwater depth (R² = 0.28 in 2023), indicating that vegetation was stressed and there was less recharge. This need is urgent because it requires an integrated water management plan to regulate urbanization and agricultural production concerning ecosystem integrity. Adopt the recommendations of enhancing water-saving practices, controlling groundwater extraction, and green infrastructures. Such research can provide the necessary basis on which policymakers can operate to mitigate the depletion of the aquifer in the rapidly developing hydrogeological environment.