At the land surface, the hydrologic cycle is strongly linked to soil water content (SWC). Land
surface models describe the mass and energy fluxes at the land surface and to the atmosphere
with a spatial resolution of a few km2 at the catchment scale. The calibration and evaluation of
land surface models requests observation data, ideally at the same spatial resolution. SWC
characterization by model prediction and observation remains a challenge in land surface
hydrology. Recently, cosmic-ray probes (CRPs) were developed for continuous passive SWC
estimation from neutron flux measurements at a scale relevant for land surface models. One
objective of this work was to set up a network of ten CRPs and to evaluate SWC estimates by
CRPs. For evaluation, the footprint average SWC of the CRPs was compared to the horizontally
and vertically weighted signal of two distributed networks of in-situ SWC sensors. Three
different parameterization methods to estimate SWC from neutron flux were compared.
Numerical complexity and potential applications distinguish the three parameterization
methods. The three parameterization methods resulted in close SWC estimates at the ten study
sites although the neutron flux – SWC relationships were slightly different amongst the
parameterization methods. SWC estimated by the calibrated CRPs was very close to SWC
measured by alternative SWC measurements. Root mean square errors (RMSEs) of the SWC
were 0.031 cm3/cm3 at the distributed in-situ SWC sensor networks. …

• Teile dieses Buch auf:
• twitter
• facebook