Applied Water Science (Oct 2020)
Distribution of aquifer characteristics in different geomorphologic units in a granitic terrain
Abstract
Abstract Knowledge of aquifer characteristics is essential for groundwater development and management studies. Detailed hydrological studies were carried out in a granitic terrain consisting of different geomorphologic units to resolve the coverage, performance, and characteristics of the aquifer parameters through the application of the pumping test method. An interpretation was performed by different methods, viz., Theis, Jacob, Hantush, and Rushton and Redshaw (numerical finite difference method) to ascertain the aquifer parameters. These parameters are vital for future groundwater development and management studies. Transmissivity (T) values estimated by Theis method range from 3.83 to 436 m2/day; 3.77 to 718 m2/day; and 16 to 160 m2/day, by Jacob method it ranges from 3.90 to 436 m2/day; 3.73 to 769 m2/day; and 17.3 to 152 m2/day, by Hantush method it ranges from 1.63 to 189 m2/day; 0.53 to 755 m2/day; and 19.3 to 118 m2/day, while by numerical method it ranges from 3 to 455 m2/day, 3 to 700 m2/day, and 17 to 148 m2/day in pediplain with moderate weathering (PPM), pediplain with shallow weathering (PPS), and buried pediplain with shallow weathering (BPPS) geomorphologic units, respectively. Similarly, a radius of influences ranges from 9.75 to 1391.0 m; 8.0 to 698.09 m, and 380.78 to 433.76 m in PPS, PPM, and BPPS geomorphologic units, respectively. The aquifer parameters obtained by the pumping tests were correlated with the structural features and different geomorphologic units. It was found that these parameters have wide variations within each geomorphologic feature. The radius of influence of each test well was calculated and compared with the in situ measured discharge of various wells within the area. The high values of transmissivity (T) are attributed to aquifer controlled by fractured zone in the area.
Keywords
