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1980~2013年滇西北地区降雨侵蚀力变化特征

1. 云南省临沧市气象局, 云南 临沧 677099
• 收稿日期:2014-06-24 修回日期:2014-09-05 出版日期:2015-10-25 发布日期:2015-10-25
• 作者简介:

作者简介：赵平伟（1983-）,男,云南临沧人,工程师,主要研究方向为气象环境。E-mail:7203956@qq.com

• 基金资助:
云南省气象局预报员专项项目（YB201215）、临沧市“短平快”科研项目资助

Spatial and Temporal Variations of Rainfall Eerosivity in Northwest Yunnan Province

Ping-wei ZHAO(), Ping GUO

1. Lincang Meteorological Bureauof Yunnan Province, Linchang, Yunnan 677099, China
• Received:2014-06-24 Revised:2014-09-05 Online:2015-10-25 Published:2015-10-25

Abstract:

Using the daily rainfall data collected in 1980-2013 from 22 meteorological sites located across Northwest Yunnan, rainfall erosion force was calculated. According to Daily rainfall, by using those methods like Mann-Kendall trend test, inverse distance weighted method, sequential Mann-Kendall test, inverse distance weighted method and R/S test, etc. We analyzed the rainfall erosivity, moderate rain, heavy rainfall, erosive rainfall, the corresponding number of days of rainfall erosivity, temporal and spatial variation, mutation time and future trends. The result showed that: in terms of the erosivity for the rainfall at each level in Northwest Yunnan, the spatial distribution of the erosivity of heavy rain was basically consistent with the spatial distribution of the erosivity of the annual rainfall, but it was much different for the spatial distribution of the annual precipitation days, the rainfall erosivity of rainstorm and the rainfall erosivity of moderate rain. For the rainfall at each level, the distributional differences of the erosivity were decreased with the smaller rainfall precipitations; 67% of the annual rainfall erosivity was generated from the rainfall erosivity of heavy rain or at a higher level that accounted for 6% of the annual precipitation days; 28% of erosive precipitation days was generated from the rainfall erosivity of heavy rain that accounted for 45% of the annual rainfall erosivity. The precipitation days for the rainfall at each level were arranged as moderate rain>heavy rain>rainstorm while the rainfall erosivity was arranged as heavy rain>moderate rain>rainstorm. The unimodal type distribution was presented with the center in July. More than 85% of the erosivity for the rainfall at each level was taken place in the rainy season (from May to October). At the same time, the higher level the rainfall was, the greater the concentration was; over the past 34 years, the corresponding rainfall erosivity, precipitation days and rainfall precipitations were increased or decreased in the Northwest Yunnan. The erosive rainfall and the annual rainfall erosivity were increased of which the growing scopes were 6.7 mm/10 a and 26.6 MJ·mm/(hm2·h·a)/10 a, respectively. The variation trends of precipitation days, precipitation and rainfall erosivity were sustainable in the future. In the small parts of the Northwest Yunnan, the rainfall erosivity for the rainfall at each level and erosive rainfall were relatively reduced. However, the variation tendency was largely distinguished for most of the parts; the erosivity for the rainfall at each level and the annual rainfall erosivity were drastically changed in 1983 of which its growth point exceeded 0.05 of the borderline at the significance level. After the period from 2002 to 2006, the growth trend was no longer apparent.

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