Long Term Groundwater Level Depletion in Mymensingh Sadar, Bangladesh: Spatio-Temporal Analysis and Sustainability Implications

Abstract

Mymensingh City is the second-most densely populated and rapidly growing modern city of Bangladesh that depends on groundwater (>90%). Due to explosive population growth, rapid urbanization, industrialization and agricultural activities in the last few years, there is a progressive increase in groundwater extraction in the study area. However, to assess the groundwater level fluctuations and depletions rates with seasonal variations through time in the groundwater aquifers, long term groundwater level monitoring data over the past 20 years were taken from the Bangladesh Water Development Board designated three monitoring wells i.e., GT6152017, GT6152020, GT6152021 and interpreted with ArcGIS 10.8 and other relevant software. A purposive survey for public opinion was also conducted where 194 respondents from 34 wards were asked about their inconveniences faced during dry months. Results show that at the three monitoring wells, the water level depletion was found to be 0.24 m/y, 0.196 m/y and 0.139 m/y and the groundwater level had dropped to 14.32 m, 9.76 m and 11.22 m, respectively. The average depth to water level during the dry season ranged from 7 to 16 m, according to the results and during the wet season was between 5 and 12 m. Wet season median groundwater level degradation was 3.23 m, while the dry season mean was 3.33 m. The results of the analysis primarily revealed declining tendencies in the studied area's time series. The present study indicates that the long-term descending pattern will maintain the existing trend patterns in the future, and the government should update the groundwater management plan to ensure that the sustainable water resources in the area are managed.