Root Distribution

Use this command to specify the spatial distribution of root water uptake.

Users must first select that part of the transport domain to which they want to assign a particular value of the selected variable. It is possible to select the entire transport domain, part of it, or only individual nodes or elements. A particular part of the transport domain can be selected as follows: first move the mouse to a selected position. The beginning and end of the operation is framed by clicking the left mouse button. The selected area is the rectangle defined by the two mouse positions when the left mouse button was clicked. When the selection is completed, users must click the Set values button and specify the value of a particular variable. The given value will then be assigned to the selected area.

Potential root water uptake may be distributed non-uniformly over a root zone of arbitrary shape. The maximum root water uptake distribution is time independent (scaled to a potential ET rate of unity and assuming no water or salinity stress). However, the root water uptake rate itself may be time dependent. The maximum root water uptake distribution reflects the distribution in the root zone of roots that are actively involved in water uptake.

The root water uptake distribution is specified in two steps. First, the spatial region occupied by the root zone is selected using the mouse; next, the relative intensity of root water uptake, b’, is specified in the pop-up window (called by clicking Set Values from the Edit Bar). The absolute value of the root uptake intensity is not important since the water uptake distribution is normalized at the beginning of the calculations.

See also the "How to Edit Domain Properties" topic.

Additional information about other Domain Properties.