Environmental Engineering Reference
Figure 4.16. Soil-water balance at a point expressed in terms of depth-average soil
moisture s in the root zone Z r .
χ = E
Figure 4.17. Schematic representation of the dependence of evapotranspiration and
leakage losses on soil moisture s . Leakage occurs only when soil moisture exceeds
field capacity s fc . Transpiration is not limited by s for s
s ∗ plants are
in a state of water stress and transpiration is a decreasing function of s . Transpiration
is zero when s is smaller than the wilting point s w .For s ranging between the
hygroscopic point s h and the wilting point s w , soil evaporation is the only contributor
to soil-moisture losses.
s ∗ .For s