Question

Two piezometers have been placed along the direction of flow in a confined aquifer that is 30.0 m thick. The piezometers are 280 m apart. The difference in piezometric head between the two is 1.4 m. The aquifer hydraulic conductivity is 50 m · day−1, and the porosity is 20%. Estimate the travel time for water to flow between the two piezometers.

Answer 1

Answer:

time = 224 days

Explanation:

given data

thick = 30 m

piezometers =  280 m

head between  two = 1.4 m

aquifer hydraulic conductivity = 50 m

porosity =  20%

solution

we get here average pole velocity that is get by using Darcy law that is

Va = $\frac{k}{\eta } \times \frac{\Delta h}{L}$   ................1

here Va is average pole velocity and k is hydraulic conductivity and $\eta$ is porosity  

here v is = $k \times \frac{dh}{dl}$   ...........2

v = 50 × $\frac{1.4}{280}$

v = 0.25 m/day

and here average linear velocity Va will be

Va = $\frac{v}{\eta }$  

Va = $\frac{0.25}{0.2}$  

Va = 1.25 m/day  

travel time for water will be

time = $\frac{280}{1.25}$  

time = 224 days