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| Titel |
Urbanization dramatically altered the water balances of a paddy field-dominated basin in southern China |
| VerfasserIn |
L. Hao, G. Sun, Y. Liu, J. Wan, M. Qin, H. Qian, C. Liu, J. Zheng, R. John, P. Fan, J. Chen |
| 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 ; 19, no. 7 ; Nr. 19, no. 7 (2015-07-31), S.3319-3331 |
| Datensatznummer |
250120774
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| Publikation (Nr.) |
 copernicus.org/hess-19-3319-2015.pdf |
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| Zusammenfassung |
| Rice paddy fields provide important ecosystem services (e.g., food
production, water retention, carbon sequestration) to a large
population globally. However, these benefits are diminishing as a
result of rapid environmental and socioeconomic transformations,
characterized by population growth, urbanization, and climate change
in many Asian countries. This case study examined the responses of
stream flow and watershed water balances to the decline of rice
paddy fields due to urbanization in the Qinhuai River basin in
southern China, where massive industrialization has occurred during
the past 3 decades. We found that stream flow increased by 58 %
and evapotranspiration (ET) decreased by 23 % during 1986–2013 as
a result of a three-fold increase in urban areas and a reduction of
rice paddy fields by 27 %. Both high flows and low flows increased
significantly by about 28 % from 2002 to 2013. The increases in
stream flow were consistent with the decreases in ET and leaf area
index monitored by independent remote sensing MODIS (Moderate
Resolution Imaging Spectroradiometer) data. Attribution analysis,
based on two empirical models, indicated that land-use/land-cover
change contributed about 82–108 % of the observed increase in
stream flow from 353 ± 287 mm yr−1 during 1986–2002 to
556 ± 145 during 2003–2013. We concluded that the reduction
in ET was largely attributed to the conversion of cropland to urban
use. The effects of land-use change overwhelmed the effects of
regional climate warming and climate variability. Converting
traditional rice paddy fields to urban use dramatically altered land
surface conditions from an artificial wetland-dominated landscape to
an urban land-use- dominated one, and thus was considered an extreme
type of contemporary hydrologic disturbance. The ongoing large-scale
urbanization of the rice paddy-dominated regions, in humid southern
China and East Asia, will likely elevate storm-flow volume,
aggravate flood risks, and intensify urban heat island effects.
Understanding the connection between land-use/land-cover change and
changes in hydrological processes is essential for better management
of urbanizing watersheds in the rice paddy-dominated landscape. |
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