Abstract. Water fluxes at the soil–atmosphere interface are a key piece of
information for studying the terrestrial water cycle. However, measuring and
modeling water fluxes in the vadose zone poses great challenges. While
direct measurements require costly lysimeters, common soil hydrologic models
rely on a correct parametrization, a correct representation of the involved
processes, and the selection of correct initial and boundary conditions.
In contrast to lysimeter measurements, soil moisture measurements are
relatively cheap and easy to perform. Using such measurements, data-driven
approaches offer the possibility to derive water fluxes directly. Here we
present FluSM (fluxes from soil
moisture measurements), which is a simple, parsimonious and robust
data-driven water balancing framework. FluSM requires only a single input
parameter (the infiltration rate) and is especially valuable for cases where
the application of Richards-based models is critical. Since permeable
pavements (PPs) present such a case, we apply FluSM on a recently published
soil moisture data set to obtain the water balance of 15 different PPs over a
period of 2 years. Consistent with findings from previous studies, our
results show that vertical drainage dominates the water balance of PPs,
while surface runoff plays only a minor role. An additional uncertainty
analysis demonstrates the ability of the FluSM-approach for water balance
studies, since input and parameter uncertainties only have a small effect on
the characteristics of the derived water balances. Due to the lack of data
on the hydrologic behavior of PPs under field conditions, our results are of
special interest for urban hydrology.
Fluxes from soil moisture measurements (FluSM v1.0): a data-driven water balance framework for permeable pavements
