HR: 0830h
AN: H31B-0456    [PDF]
TI: Identifying Monitoring Sites for Catchment-scale Soil Moisture Based on Hydrological Modeling
AU: * Janssens, V E
EM: valerie.janssens@ugent.be
AF: Laboratory of Hydrology and Water Management, Coupure links 653, Gent, B-9000 Belgium
AU: Verhoest, N E
EM: niko.verhoest@ugent.be
AF: Laboratory of Hydrology and Water Management, Coupure links 653, Gent, B-9000 Belgium
AU: De Troch, F P
EM: francois.detroch@ugent.be
AF: Laboratory of Hydrology and Water Management, Coupure links 653, Gent, B-9000 Belgium
AB: Soil moisture plays an important role in partitioning rainfall into runoff and infiltration, and the incoming radiation into latent, sensible and ground heat fluxes, and is therefore an important variable in distributed hydrological models. Monitoring soil moisture at the catchment scale requires intensive field campaigns which are, from a logistic point of view, difficult to perform at a regular time interval. Remote sensing could provide an answer, however, its results should be validated against ground truth. Recently, Grayson and Western (1998) demonstrated the existence of Catchment-Average-Soil-Moisture-Monitoring (CASMM) sites which may provide relevant information with respect to the catchment average soil moisture behavior and allow to retrieve reliable estimates of areal soil moisture from a limited number of sample locations. However these sites do not provide information on the spatial variability in soil moisture and additional sites should be identified which allow to capture the spatial soil moisture pattern. In order to bypass intensive field campaigns necessary to identify these monitoring sites, a modeling approach is adopted which investigates soil moisture behavior. CASMM sites as well as other sites are identified and checked for their stability in time. The study is performed on a 2.26~km$^2$ subcatchment of the Zwalm basin (Belgium) where intensive field campaigns are currently conducted. Preliminary results are checked against modeling results to verify whether hydrological models can be used to localize relevant soil moisture monitoring sites. Grayson, R.B., Western, A.W., Towards areal estimation of soil water content from point measurements: time and space stability of mean response, Journal of Hydrology, 207(1-2), 68-82, 1998.
DE: 1800 HYDROLOGY
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2003 Fall Meeting