 |
| Titel |
Evapotranspiration and water yield over China's landmass from 2000 to 2010 |
| VerfasserIn |
Y. Liu, Y. Zhou, W. Ju, J. Chen, S. Wang, H. He, H. Wang, D. Guan, F. Zhao, Y. Li, Y. Hao |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1027-5606
|
| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 12 ; Nr. 17, no. 12 (2013-12-10), S.4957-4980 |
| Datensatznummer |
250086025
|
| Publikation (Nr.) |
 copernicus.org/hess-17-4957-2013.pdf |
|
|
|
|
|
| Zusammenfassung |
Terrestrial carbon and water cycles are interactively linked at various
spatial and temporal scales. Evapotranspiration (ET) plays a key role in the
terrestrial water cycle, altering carbon sequestration of terrestrial
ecosystems. The study of ET and its response to climate and vegetation
changes is critical in China because water availability is a limiting factor
for the functioning of terrestrial ecosystems in vast arid and semiarid
regions. To constrain uncertainties in ET estimation, the process-based
Boreal Ecosystem Productivity Simulator (BEPS) model was employed in
conjunction with a newly developed leaf area index (LAI) data set, MODIS
land cover, meteorological, and soil data to simulate daily ET and water
yield at a spatial resolution of 500 m over China for the period from 2000
to 2010. The spatial and temporal variations of ET and water yield were
analyzed. The influences of climatic factors (temperature and precipitation)
and vegetation (land cover types and LAI) on these variations were assessed.
Validations against ET measured at five ChinaFLUX sites showed that the BEPS
model was able to simulate daily and annual ET well at site scales.
Simulated annual ET exhibited a distinguishable southeast to northwest
decreasing gradient, corresponding to climate conditions and vegetation
types. It increased with the increase of LAI in 74% of China's landmass
and was positively correlated with temperature in most areas of southwest,
south, east, and central China. The correlation between annual ET and
precipitation was positive in the arid and semiarid areas of northwest and
north China, but negative in the Tibetan Plateau and humid southeast China.
The national annual ET varied from 345.5 mm in 2001 to 387.8 mm in 2005,
with an average of 369.8 mm during the study period. The overall rate of
increase, 1.7 mm yr−1 (R2 = 0.18, p = 0.19), was mainly driven by
the increase of total ET in forests. During 2006–2009, precipitation and LAI
decreased widely and consequently caused a detectable decrease in national
total ET. Annual ET increased over 62.2% of China's landmass, especially
in the cropland areas of the southern Haihe River basin, most of the Huaihe
River basin, and the southeastern Yangtze River basin. It decreased in parts
of northeast, north, northwest, south China, especially in eastern
Qinghai-Tibetan Plateau, the south of Yunnan Province, and Hainan Province.
Reduction in precipitation and increase in ET caused vast regions in China,
especially the regions south of Yangtze River, to experience significant
decreases in water yield, while some sporadically distributed areas
experienced increases in water yield. This study shows that the terrestrial
water cycles in China's terrestrial ecosystems appear to have been
intensified by recent climatic variability and human induced vegetation changes. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|