Evaluation of Ground Water Resources in Mymensingh Sadar Upazilla, Bangladesh

A study was conducted to make an overall assessment of aquifer, groundwater resources, and its optimum utilization as well as the potentiality of groundwater abstraction in Mymensingh sadar upazilla. The subsurface lithology was investigated from the collected data of twelve borelogs in the study area. The subsurface formation of the study area was stratified with clay, sandy clay and fine sand at the upper part while medium sand, coarse sand at the lower part of subsurface lithology. The thickness of clay and silty or sandy clay layers ranging from 6 m to 58 m having an average thickness of 33.8 m existed below the ground surface. The thickness of composite aquifer varied from 13 m to 75 m having average thickness of 27.6 m. Main aquifer or exploitable aquifer thickness varied from 23 m to 61 m having average thickness of 43.8 m. Transmissibility of the aquifer found by applying Jacob’s time-drawdown method was 1037 m2/day to 4430 m2/ day and the average is 3154 m2/day. The static water level started rising from the month of April and continued to rise up to the month of September or October The water level started to deplete from September to October and continued up to April. Average specific draw-down was 114.8 m/cumec and average specific capacity was 4.7x10-4 cumec/m obtained by multi-step pumping test method. The recharge and depletion characteristics were found to be almost in equilibrium condition. The long-term trend of ground water level was found to be in declining position in the recent years.