Question

An irrigation pond is built from an impermeable concrete cylinder installed in a hole with deep(saturated) clay soils lying at the bottom the pond. The clay has a hydraulic conductivity of 1x10-3 m/day. During summer, evaporation leads to a loss of 5 mm/day from the pond.The pond contains 50 cm depth of water at the beginning of summer. Assume that the pressure in the pore water below the pond is zero everywhere, and that it is the flux of water in the soil (regardless of the stored depth of water in the pond) that drives the drainage from the pond. A. Write an expression for the amount of time (At ) it takes for the pond to dry out, in terms of the change in storage (AS) and the vertical fluxes out of the pond control volume (E and 9₂), which you should define as fluxes leaving the control volume (i.e., both fluxes will be positive, meaning E points in the +z direction and q₂ in the -z direction). B. How long does it take for the pond to dryout? C. The fact that water was flowing vertically in(A) and (B) means that we do not have hydrostatic pressure within the soil. Assuming uniformity in the x and y directions and the z-axis oriented upward, in what range must the

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