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| Paper Code |
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| Title |
Spatio-temporal variation of the wet-dry conditions from 1961 to 2015 in China |
| Authors |
Yuan QuanZhi; Wu ShaoHong; Dai ErFu; Zhao DongSheng etc. |
| Corresponding Author |
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| Year |
2017 |
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| Volume |
SCIENCE CHINA-EARTH SCIENCES |
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| Abstract |
As an important part of the regional environment, the wet-dry climate condition is determined by precipitation and potential evapotranspiration (expressed as ET (o)). Based on weather station data, this study first calculated ET (o) by using the FAO56 Penman-Monteith model. Then, the dryness index K (ratio of ET (o) to precipitation) was used to study the spatio-temporal variation of the wet-dry condition in China from 1961 to 2015; moreover, dominant climatic factors of the wet-dry condition change were discussed. The annual precipitation and ET (o) of the Qinling-Huaihe line were close to a balance (K approximate to 1.0). The annual precipitation in most areas exceeded the ET (o) in the south of this line and the east of Hengduan Mountains (K<1.0), where the climate is wet. Furthermore, the precipitation in the northwest inland areas of China, where the climate is dry, was markedly lower than ET (o) (K >= 4.0). The overall annual K of China fluctuated around the 55-year mean and its linear trend was not significant. However, a relatively wet period of about 10 yr (1987-1996) was recorded. The overall annual K of China showed strong cyclicality on the time scale of 3, 7-8, 11 and 26-28 yr, and regional differences of the annual K trends and cyclicality were large. The degrees of wetness in the Northwest China and western Qinghai-Tibet Plateau were substantially increased, whereas the degrees of dryness in the Yunnan-Guizhou Plateau, Sichuan Basin, and Loess Plateau were markedly increased. The linear trend of the annual K in most regions of China was not significant, and the annual K of most areas in China showed strong cyclicality on the 8-14 yr time scale. Precipitation was the dominant factor of wet-dry condition change in most areas, especially in North China, where the annual K change was highly correlated with precipitation. |
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| Classification: |
SCI |
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| Title of Journal: |
SCIENCE CHINA-EARTH SCIENCES |
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