An interception model that Links the temporal variability of rainfall with
the storm-based description of the interception process is derived. Analyti
cal formulae for long-term interception loss are obtained for precipitation
with statistical characteristics derived from observations.
The analysis of the results indicates that the point interception loss is c
ontrolled primarily by three time scales: the mean inter-storm arrival time
tau(a), the mean storm duration tau(n), and the time to evaporate a satura
ted canopy tau(r), which depends on canopy water holding capacity W-e and t
he wet canopy potential evaporation rate E-10,. and less importantly, on st
orm intensity. Additional assumption of rainfall stationarity lends to a re
lation between long-term interception loss and gross rainfall that requires
a very small amount of input data.
The interception loss predicted by the analytical model agrees well with th
at of a Rutter model driven by a synthetic rainfall time series with the sa
me statistics. Using the parameter values estimated from the observed rainf
all data in the Amazon and southwestern France, the analytical results pred
ict a long-term interception loss close to that observed. (C) 2000 Elsevier
Science B.V. All rights reserved.