Groundwater Hydrology - Irrigation and Drainage Engineering - Agricultural Engineering Previous Year Questions

An unconfined aquifer is pumped at a constant rate of 10 l s\(^{-1}\). Steady state drawdowns measured at radial distances of 30 m and 60 m are 0.80 m and 0.70 m, respectively. Original thickness of aquifer is 30 m. Transmissibility of the aquifer is

A recharge well of 300 mm diameter is constructed in a confined aquifer of 1000 m\(^2\) d\(^{-1}\) transmissibility. From the top of impermeable bed, the water level in the well is 50 m and the height of constant water level is 40 m. The constant water level occurs at a distance of 150 m from the center of the well. The possible maximum recharge rate is

An unconfined aquifer extends over an area of \(1 \text{ km}^2\) and has hydraulic conductivity, total porosity and specific retention of \(20 \text{ m per day}\), 30% and 10%, respectively. After pumping some groundwater from this aquifer, the water table dropped to a depth of \(20 \text{ m}\) from the ground level. If the water table was initially at \(14.5 \text{ m}\) below the ground level, the change in groundwater storage in million cubic meters would be ________

Two parallel canals 50 m apart fully penetrate a homogeneous unconfined aquifer resting on a horizontal impermeable layer. The aquifer has a hydraulic conductivity of \(3 \text{ m day}^{-1}\) and an effective porosity of 0.25. One-dimensional steady groundwater flow occurs from the upper canal to the lower canal with the height of water levels in the canals 10 m and 8.5 m from the aquifer bottom, respectively. If a sediment layer of \(4 \text{ cm}\) thick with hydraulic conductivity of \(1.2 \times 10^{-2} \text{ m day}^{-1}\) is ultimately deposited on the inflow face, the groundwater discharge per 1000 m width between the two canals in \(\text{m}^3 \text{ day}^{-1}\) will be ________

A well fully penetrates a 30 m thick confined aquifer. After a long period of pumping at a constant rate of 0.06 m³·s⁻¹, drawdowns of 3.6 m and 2.0 m are found at distances 60 m and 120 m away from the well, respectively. The hydraulic conductivity of the aquifer is n × 10⁻⁴ m·s⁻¹. The value of n is _____. (Rounded off to two decimal places)