[1]CAO Yan,WANG Jie,HUANG Ying,et al.Variation Characteristics of Dry-Wet Conditions in Central Yunnan in Recent 45 Years Based on Dry Index[J].Research of Soil and Water Conservation,2018,25(01):243-249.
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
25
Number of periods:
2018 01
Page number:
243-249
Column:
Public date:
2018-02-28
- Title:
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Variation Characteristics of Dry-Wet Conditions in Central Yunnan in Recent 45 Years Based on Dry Index
- Author(s):
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CAO Yan, WANG Jie, HUANG Ying, ZHANG Lei, QI Na
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Yunnan Institute of Water Resources and Hydropower Research, Kunming 650228, China
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- Keywords:
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dry index; dry-wet conditions; central Yunnan; spatial and temporal distribution; variation trend
- CLC:
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P468.0
- DOI:
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- Abstract:
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Based on the meteorological date of 9 stations in central Yunnan from 1970 to 2014, the dry index was estimated using the FAO Penman-Monteith formula, and the temporal and spatial variation characteristics of dry-wet conditions in central Yunnan were analyzed by Mann-Kendall test and 5-year moving average method. The result showed that there was a significant positive correlation between the actual evapotranspiration and the potential evapotranspiration in central Yunnan. The results also showed that:(1) the potential evapotranspiration calculated by Penman-Monteith formula was suitable for central Yunnan Province; (2) the annual average value of dry index was 1.55, the overall dry index had increased with an increasing rate of 0.063/decade from 1970 to 2014, the dry index had decreased with a decreasing rate of 0.025/decade in spring, the dry index had increased with an increasing rate of 0.024/decade, 0.111/decadeand 0.476/decade in summer, autumn and winter, repectively, which indicated the significant upward trend in autumn, the abrupt change of dry index happened in 2009 and around 1970s; (3) the dry index was most affected by precipitation in central Yunnan, the main space characteristics of dry index was high in central and low in east and west, the maximum value of dry index appeared in winter, and the value of dry index in spring was higher than that in autumn, the minimum value of dry index occurred in summer; (4) at the annual scale, the dry trend was more and more obvious from the midwest to the east, the wet trend was more and more obvious from the east to the midwest in spring, the dry trend was more and more obvious from the middle to the east and the west in summer, the dry trend was more and more obvious from northwest to southeast in autumn, the wetweed areas mainly distributed in the central region, northeast and southeast, the drying area mainly distributed in the northwest in winter.