Course is Water Resources. Solve with step by step and clear writing please. 3.3
ID: 1713940 • Letter: C
Question
Course is Water Resources. Solve with step by step and clear writing please.
3.3. A drainage basin which covers an area of As-900 km2 is completely made up of limestone with an average thickness of B = 100m. The porosity of limestone is n = 20%. Estimate the total volume of water stored in the aquifer, SG, if it were saturated. Estimate the annual total volume of water that could be pumped from the aquifer without a long term decrease in the GW storage if average annual precipitation (P), evapotranspiration (Er) and surface runoff over the area (Qs) are 55cm, 20 cm, and 11cm, respectively.Explanation / Answer
Solution:-a)
Area= 900 km2
B=100 m
Volume = Area * thickness
Volume= 900 *1000000 m2*100m
Volume= 90 km3
Total volume of water stored = Volume/porosity
Total volume of water stored = 90 km3/0.2
Total volume of water stored = 450 km3
b) Total depth of water = P- ET-QS
Total depth of water= 55-20-11
Total depth of water = 24 cm
Total depth of water 0.24 m
Volume= 900* 1000000 m2 * 0.24 m
Volume = 0.0216 km3
Total annual volume = Volume/ porosity
Total annual volume= 0.0216/0.2
Total annual volume= 0.108 km3.