January 27, 2020 by
Soil Hydraulic Functions in Matlab
Water Retention Functions
The van Genuchten (1980) model is the most widely used water retention curve function:
\[\Theta = \left( 1 +(\alpha \psi)^n\right)^{-m}\]where the effective saturation is defined as:
\[\Theta = \frac{(\theta - \theta_{r})}{ (\theta_{s} - \theta_{r})}\]The hydraulic conductivity function is defined using Mualem Model.
The hydraulic capacity function.
The following function takes a scalr or vector of u as input:
test
function [q,k,c] = Mualem_vanGenuchten(x,u,qr,por,a,n,ks)
mu = 0.5;
m = 1-1/n;
UZ = u<0;
Q = (1-UZ)*1 + UZ .* ((1+(-a.*u).^n).^(-m));
q = qr+(por-qr)*Q;
k = ks*(Q.^mu).*(1-(1-Q.^(1/m)).^m).^2 ;
c = (1-UZ)*0+ UZ.*(((por-qr)*n*m*a.*(-a.*u).^(n-1))./((1+(-a.*u).^n).^(m+1)));
end