Pressure Head Reduction - S-Shape

The Root Water Uptake Parameters for the S-shaped water stress response function as suggested by van Genuchten [1987] are as follows:

P50         The coefficient, h50, in the root water uptake response function associated with water stress [L]. Root water uptake at this pressure head is reduced by 50%.

P3         The exponent, p3, in the root water uptake response function associated with water stress [-]; its recommended value is 3.

We have additionally included parameter PW, i.e., pressure head at wilting point [L], below which transpiration stops.

Other Topics:

Root Water Uptake Models

Pressure Head Reduction - the Feddes Model

Osmotic Reduction of Root Water Uptake

Root Distribution Parameters

Root Growth Parameters