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| Titel |
Integrated validation of modeled plant growth, nitrogen- and water-fluxes in the agricultural used Rur catchment in Western Germany |
| VerfasserIn |
Wolfgang Korres, Christian Klar, Tim Reichenau, Peter Fiener, Karl Schneider |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037599
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| Zusammenfassung |
| Numerous studies have shown that agricultural management is one of the key drivers for
spatio-temporal patterns of soil moisture in agricultural landscapes. The process-based
ecohydrological model components of the integrated decision support system DANUBIA are
used to identify the important processes and feedbacks determining soil-moisture patterns in
agroecosystems. Interactions between plant growth, soil hydrology and soil nitrogen
transformation processes are modeled by using a dynamically coupled modeling approach.
Integrative validation of all three model components serves as a basis for modeling analysis
of spatial soil moisture patterns.
DANUBIA is parameterized and validated for the Rur catchment located in Western
Germany. For integrative validation, an extensive three year dataset (2007 – 2009)
of soil moisture- (TDR, FDR), plant- (LAI, organ specific biomass and N) and
soil- (texture, N, C) measurements was acquired. Plant measurements on an arable
land test site were carried out biweekly. Measurements were conducted for winter
wheat, maize and sugar beet during the growing season. Soil nitrogen and carbon
measurements were taken before, during and after the growing season. Field averages of
plant and soil parameters are derived from three individual measuring locations
within each test field. Soil moisture was measured with three FDR soil moisture
stations in 10 and 30 cm depth. In a grassland test site biomass measurements were
carried out biweekly in 2009. Soil moisture was monitored at different locations in
up to 60 cm soil depth using FDR- and TDR-stations. Meteorological data was
measured with an eddy flux (arable land) and energy flux station (grassland test
site).
First results of point validation are in very good agreement with field measurements.
Model results for winter wheat in 2007/2008 match field measurements well for
both, the overall biomass (R2= 0.97, rel. RMSE = 16.8%, Nash Sutcliff – model
efficiency ME = 0.96) as well as for individual plant organs (e.g., storage organ:
ME = 0.99, living leaf: ME = 0.79). Modeled LAI provide a R2= 0.87 and a ME
value of 0.77. Surface soil moisture in the upper layer showed an R2of 0.73, an
absolute RMSE of 3.8 Vol.-% and a ME value of 0.12. However, the agreement
of model results with soil moisture measurements decreases with increasing soil
depth.
Our ongoing research aims at analyzing spatial patterns of soil moisture and vegetation
parameters for the Rur catchment and particularly upon utilizing soil moisture maps retrieved
by radar remote sensing for this purpose. |
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