1.Determine the normal depth in a trapezoidal channel with a bottom width of 50 ft, side slope of 3:1, and a bed slope of 0.0015 ft/ft. The Manning’s n value is 0.020 and the discharge is 4,000 cfs.
2.Assume that water recharging an aquifer in 1964 had a tritium concentration of 1200 TU at that time. If this water is not mixed with other waters, predict its tritium concentration in 1970, 1980, 1990, 2000, and 2100.
3.A ground water sample has a pH of 7.5, hardness (due to primarily Ca2+) of 100 mg/L, and an alkalinity of 250 mg/L as CaCO3(s). Is the calcite precipitating or dissolving in the pore water? (Alkalinity = [HCO3-] + 2[CO32-]+[OH-]-[H+])
4.Groundwater is pumped for domestic use from an unconfined aquifer. the thickness of the clay is 40%. after 10 years of pumping, the porosity is reduced to 30%. determine the subsidence of the clay surface.