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| Titel |
Vegetation control on water and energy balance within the Budyko framework |
| VerfasserIn |
Dan Li, Zhentao Cong, Ming Pan, Lu Zhang |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250077765
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| Zusammenfassung |
| Budyko’s framework has been widely used to study basin-scale water and energy balances
and one of the formulations of the Budyko curve is Fu’s equation. The curve shape parameter
Ï in Fu’s equation controls how much of the available water will be evaporated given the
available energy. Previous studies have found that land surface characteristics significantly
affect variations in the parameter Ï. In this study, we focus on the vegetation impact and
examine the conditions under which vegetation plays a major role in controlling the
variability of Ï. Using data from 26 major global river basins that are larger than
300,000km2, the basin-specific Ï parameter is found to be linearly correlated with the
long-term averaged annual vegetation coverage. A simple parameterization for the Ï
parameter based solely on remotely-sensed vegetation information improves predictions of
annual actual evapotranspiration by reducing the root mean square error (RMSE) from
76 mm to 47 mm as compared to the default Ï value used in the Budyko curve
method. The controlling impact of vegetation on the basin-specific Ï parameter is
diminished in small catchments with areas less than 50,000km2, which suggests a
scale-dependence of the role of vegetation in affecting water and energy balances.
In small catchments, other key ecohydrological processes need to be taken into
account in order to fully capture the variability of the Ï parameter in Fu’s equation. |
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