Estimating Hydraulic Conductivity, Transmissibility and Specific Yield of Aquifer in Barind Area, Bangladesh Using Pumping Test

Abstract

Reliable hydraulic parameters values are essential and crucial basic data for potential groundwater withdrawal (aquifer yield) and also for sustainable groundwater management. They are also essential for simulation model study for different management scenario analyses. The laboratory test has limitations, while in situ tests produce representative aquifer parameters. The pumping test method is the only method that provides simultaneous information on the hydraulic behavior of the well, the aquifer, and the aquifer boundaries. Pumping tests were performed to determine aquifer hydraulic properties such as hydraulic conductivity (K), transmissibility (T), and specific yield (Sy) at two Upazilas of the Barind area, namely Nachol and Niamatpur. The aquifer formation is composed of layers: upper fine sand, medium sand, a conductive sand layer, and lower fine sand at the bottom, below which the impervious clay layer exists. The K was determined through Dupit’s steady radial flow equation, T through Theis’s and Copper-Jacob approach, and Sy through Copper-Jacob and gravity drainage of aquifer materials. The mean K, T, and Sy were found as 30.3 m3/m2/day, 756.7 m3/m/day, and 4.6%, respectively for the Nachol location; and 52.7 m3/m2/day, 1027.3 m3/m/day and 6.6%, respectively for Niamatpur location. The values obtained are supported by regional values reported earlier, and also by other locations’ values situated elsewhere having similar aquifer materials. To achieve long-term sustainability in the studied locations, withdrawal of groundwater resources should be optimized considering the aquifer hydraulic properties values.