Consider a two-dimensional flow through isotropic soil along $x$ direction and $z$ direction. If $h$ is the hydraulic head, the Laplace's equation of continuity is expressed as
(A) $\frac{\partial h}{\partial x}+\frac{\partial h}{\partial z}=0$
(B) $\frac{\partial h}{\partial x}+\frac{\partial h}{\partial x} \frac{\partial h}{\partial z}+\frac{\partial h}{\partial z}=0$
(C) $\frac{\partial^{2} h}{\partial x^{2}}+\frac{\partial^{2} h}{\partial z^{2}}=0$
(D) $\frac{\partial^{2} h}{\partial x^{2}}+\frac{\partial^{2} h}{\partial x \partial z}+\frac{\partial^{2} h}{\partial z^{2}}=0$
Consider a two-dimensional flow through isotropic soil along $x$ direction and $z$ direction. If $h$ is the hydraulic head, the Laplace's equation of continuity is expressed as
(A) $\frac{\partial h}{\partial x}+\frac{\partial h}{\partial z}=0$
(B) $\frac{\partial h}{\partial x}+\frac{\partial h}{\partial x} \frac{\partial h}{\partial z}+\frac{\partial h}{\partial z}=0$
(C) $\frac{\partial^{2} h}{\partial x^{2}}+\frac{\partial^{2} h}{\partial z^{2}}=0$
(D) $\frac{\partial^{2} h}{\partial x^{2}}+\frac{\partial^{2} h}{\partial x \partial z}+\frac{\partial^{2} h}{\partial z^{2}}=0$
$\frac{\partial^{2} h}{\partial x^{2}}+\frac{\partial^{2} h}{\partial z^{2}}=0$