TY - JOUR
T1 - Remotely sensed evapotranspiration to calibrate a lumped conceptual model
T2 - Pitfalls and opportunities
AU - Willem Vervoort, R.
AU - Miechels, Susannah F.
AU - van Ogtrop, Floris F.
AU - Guillaume, Joseph H.A.
N1 - Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/27
Y1 - 2014/11/27
N2 - Physically representative hydrological models are essential for water resource management. New satellite evapotranspiration (ETobs) data might offer opportunities to improve model structure and parameter identifiability, if used as an independent calibration set. This study used a modelling experiment on 4 catchments in New South Wales, Australia, to investigate whether MODIS (16A3) ETobs can be used to improve parameter calibration for low parameter conceptual models. The catchment moisture deficit and exponential routing form of the model IHACRES was used to test calibration against streamflow, MODIS ETobs or a combination setoff the two. Results were compared against a regionalized parameter model and a model using MODIS ETobs directly as input. Firstly, the results indicated that the observed water balance of the catchments has, currently unexplained, large positive differences which impact the calibrated parameters. More generally, using MODIS ETobs as a calibration set, results in a reduction of the model performance as all residuals of the local water balance and timing differences between the water balance and the outflow need to be resolved by the routing component of the model. This is further complicated by variations in land cover affecting the MODIS ETobs. Finally this study confirms that the calibration of models using multiple environmental timeseries (such as MODIS ETobs and Q) can be used to identify structural model issues.
AB - Physically representative hydrological models are essential for water resource management. New satellite evapotranspiration (ETobs) data might offer opportunities to improve model structure and parameter identifiability, if used as an independent calibration set. This study used a modelling experiment on 4 catchments in New South Wales, Australia, to investigate whether MODIS (16A3) ETobs can be used to improve parameter calibration for low parameter conceptual models. The catchment moisture deficit and exponential routing form of the model IHACRES was used to test calibration against streamflow, MODIS ETobs or a combination setoff the two. Results were compared against a regionalized parameter model and a model using MODIS ETobs directly as input. Firstly, the results indicated that the observed water balance of the catchments has, currently unexplained, large positive differences which impact the calibrated parameters. More generally, using MODIS ETobs as a calibration set, results in a reduction of the model performance as all residuals of the local water balance and timing differences between the water balance and the outflow need to be resolved by the routing component of the model. This is further complicated by variations in land cover affecting the MODIS ETobs. Finally this study confirms that the calibration of models using multiple environmental timeseries (such as MODIS ETobs and Q) can be used to identify structural model issues.
KW - Calibration
KW - MODIS 16A3 ET
KW - Model uncertainty
KW - Rainfall runoff
UR - http://www.scopus.com/inward/record.url?scp=84919935208&partnerID=8YFLogxK
U2 - 10.1016/j.jhydrol.2014.10.034
DO - 10.1016/j.jhydrol.2014.10.034
M3 - Article
SN - 0022-1694
VL - 519
SP - 3223
EP - 3236
JO - Journal of Hydrology
JF - Journal of Hydrology
IS - PD
ER -