Searching for the Holy Grail of scientific hydrology: Qt=(S, R, Δt)A as closure
Other literature type
English
OPEN
Beven, K.
(2006)
Representative Elementary Watershed concepts provide a useful
scale-independent framework for the representation of hydrological processes.
The balance equations that underlie the concepts, however, require the
definition of boundary flux closures that should be expected to be scale
dependent. The relationship between internal state variables of an REW
element and the boundary fluxes will be nonlinear, hysteretic and
scale-dependent and may depend on the extremes of the heterogeneities within
the REW. Because of the nonlinearities involved, simple averaging of local
scale flux relationships are unlikely to produce an adequate decription of
the closure problem at the REW scale. Hysteresis in the dynamic response is
demonstrated for some small experimental catchments and it is suggested that
at least some of this hysteresis can be represented by the use of simple
transfer functions. The search for appropriate closure schemes is the second
most important problem in hydrology of the 21st Century (the most important
is providing the techniques to measure integrated fluxes and storages at
useful scales). The closure problem is a scientific Holy Grail: worth
searching for even if a general solution might ultimate prove impossible to
find.