Question $1$

The permeability co$-$efficient $(k)$ for radial flow in a confined aquifer of thickness $H$ is given by

the expression:

$k=\frac{q}{2H(h_2-h_1)}lo{g}_e\frac{r_2}{r_1}$

If a clay layer of thickness $4m$ overlies an aquifer of thickness $8m,$ which in turn overlies

rock. The well is driven to bedrock, $q$ is $1$ million litres$/$day$.r_1$ and $r_2$ are $10m$ and $20m,$ and

water levels were recorded $4\mathrm{.}25m$ and $2\mathrm{.}75m$ below ground level.

a$)$ Draw a sketch representing the above information graphically.

b$)$ Determine k$.$ Comment on the soil type based on calculated coefficient of

permeability.

c$)$ If the initial water level was $2\mathrm{.}0m$ below the ground, calculate the radius of influence

$(r_0)$ of the well at the given pumping rate.