Flow through unconfined vertically stratified aquifer

Fig. 9.2 Phreatic aquifer with two vertical strata

Consider the vertically stratified aquifer as shown in Fig. 9.2 above. The left strata has the hydraulic conductivity of K₁ and the right strata has the hydraulic conductivity of K₂. If we consider the first strata

(9.7)

Integrating from x = 0, h(x) = h₁ and x = L₁, h(x) = h₃, we can obtain,

(9.8) (9.9)

Similarly for the second strata, we can obtain

(9.10)

Equating equations (9.9) and (9.10), we have

(9.11) (9.12) (9.13)

Equation (2.13) can be used for calculating discharge through the vertically stratified unconfined aquifer.

In case of n numbers of strata, the equation can be expressed as

(9.14)

Equation (9.14) can be used to calculate the discharge through the vertically stratified unconfined aquifer.