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| Titel |
Assessing the impact of climate variability on catchment water balance and vegetation cover |
| VerfasserIn |
X. Xu, D. Yang, M. Sivapalan  |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 16, no. 1 ; Nr. 16, no. 1 (2012-01-06), S.43-58 |
| Datensatznummer |
250013111
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| Publikation (Nr.) |
 copernicus.org/hess-16-43-2012.pdf |
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| Zusammenfassung |
| Understanding the interactions among climate, vegetation cover and the water
cycle lies at the heart of the study of watershed ecohydrology. Recently,
considerable attention is being paid to the effect of climate variability on
catchment water balance and also associated vegetation cover. In this paper,
we investigate the general pattern of long-term water balance and vegetation
cover (as reflected by fPAR) among 193 study catchments in Australia through
statistical analysis. We then employ the elasticity analysis approach for
quantifying the effects of climate variability on hydrologic partitioning
(including total, surface and subsurface runoff) and on vegetation cover
(including total, woody and non-woody vegetation cover). Based on the
results of statistical analysis, we conclude that annual runoff (R),
evapotranspiration (E) and runoff coefficient (R/P) increase
with vegetation cover for catchments in which woody vegetation is
dominant and annual precipitation is relatively high. Control of water
available on annual evapotranspiration in non-woody dominated catchments is
relatively stronger compared to woody dominated ones. The ratio of
subsurface runoff to total runoff (Rg/R) also increases with woody
vegetation cover. Through the elasticity analysis of catchment runoff, it is
shown that precipitation (P) in current year is the most important factor affecting the change in
annual total runoff (R), surface runoff (Rs) and subsurface runoff (Rg). The significance
of other controlling factors is in the order of annual precipitation in
previous years (P−1 and P−2), which represents the net effect of
soil moisture and annual mean temperature (T) in current year. Change of
P by +1% causes a +3.35% change of R, a +3.47% change of Rs and
a +2.89% change of Rg, on average. Results of elasticity analysis on
the maximum monthly vegetation cover indicate that incoming shortwave radiation during the growing
season (Rsd,grow) is the most important
factor affecting the change in vegetation cover. Change of Rsd,grow by
+1% produces a −1.08% change of total vegetation cover (Ft) on
average. The significance of other causative factors is in the order of
precipitation during growing season, mean temperature during growing season
and precipitation during non-growing season. Growing season precipitation is
more significant than non-growing season precipitation to non-woody
vegetation cover, but both have equivalent effects to woody vegetation
cover. |
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