 |
| Titel |
Towards reduced uncertainty in catchment nitrogen modelling: quantifying the effect of field observation uncertainty on model calibration |
| VerfasserIn |
K. J. Raat, J. A. Vrugt, W. Bouten, A. Tietema |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 8, no. 4 ; Nr. 8, no. 4, S.751-763 |
| Datensatznummer |
250005731
|
| Publikation (Nr.) |
 copernicus.org/hess-8-751-2004.pdf |
|
|
|
|
|
| Zusammenfassung |
| The value of nitrogen (N) field measurements for the calibration of parameters of the INCA nitrogen in catchment model is
explored and quantified. A virtual catchment was designed by running INCA with a known set of parameters, and field "measurements" were selected
from the model run output. Then, using these measurements and the Shuffled Complex Evolution Metropolis algorithm (SCEM-UA), four of the INCA
model parameters describing N transformations in the soil were optimised, while the measurement uncertainty was increased in subsequent steps.
Considering measurement uncertainty typical for N field studies, none of the synthesised datasets contained sufficient information to identify
the model parameters with a reasonable degree of confidence. Parameter equifinality occurred, leading to considerable uncertainty in model
parameter values and in modelled N concentrations and fluxes. Fortunately, combining the datasets in a multi-objective calibration was found to
be effective in dealing with these equifinality problems. With the right choice of calibration measurements, multi-objective calibrations
resulted in lower parameter uncertainty. The methodology applied in this study, using a virtual catchment free of model errors, is proposed as
a useful tool foregoing the application of a N model or the design of a N monitoring program. For an already gauged catchment, a virtual study
can provide a point of reference for the minimum uncertainty associated with a model application. When setting up a monitoring program, it can
help to decide what and when to measure. Numerical experiments indicate that for a forested, N-saturated catchment, a fortnightly sampling of
NO3 and NH4 concentrations in stream water may be the most cost-effective monitoring strategy.
Keywords: INCA, nitrogen model, parameter uncertainty, multi-objective calibration, virtual catchment, experimental design |
| |
|
| Teil von |
|
|
|
|
|
|
|
|