1961—2010年怒江流域降雨侵蚀力的时空变化特征

Spatio-temporal variation characteristics of rainfall erosivity during 1961-2010 in Nu river basin

为研究怒江流域降雨侵蚀力的时空分布特征,利用怒江流域内6个气象站点1961—2010年的日降雨量资料,根据日降雨侵蚀力模型,采用Mann-Kendall非参数检验法和反距离权重插值法分析流域降雨量和降雨侵蚀力的时空分布规律。结果表明:怒江流域多年平均降雨量为774.93 mm,多年平均降雨侵蚀力为1 842.45(MJ·mm)/(hm^2·h);其中,降雨量在1978年发生突变,降雨侵蚀力在1966、1973和1976年产生突变,流域降雨量和降雨侵蚀力均呈现东南高,西北低的变化趋势,降雨侵蚀力年内分布主要集中在夏季,占比达48.71%,冬季最小,占比只有5.9%。怒江流域降雨量和降雨侵蚀力空间分布相似,侵蚀性雨量对降雨侵蚀力的影响更大。研究结果可为怒江流域水土保持,生态修复等工作提供一定的技术参考。

Background]One of the main factors of soil erosion is rainfall.Rainfall erosivity is an important indicator for studying soil erosion due to rainfall,and it is one of the important parameters of many soil erosion models.Correct calculation of rainfall erosivity has important practical significance for soil erosion and soil and water conservation in the study area.In order to study the temporal and spatial distribution characteristics of rainfall erosivity in the Nu river basin.Using the daily rainfall data of 6weather stations in the Nu river basin from 1961 to 2010.[Methods]The methods used in this paper mainly include calculating the rainfall erosivity of the basin by using the daily rainfall erosivity model,Mann-Kendall nonparametric statistical method for the mutation calculation,and interpolating the rainfall and rainfall erosivity of the basin using the inverse distance weight interpolation method in Arcgis 10.2software.The temporal and spatial distribution of force.In order to provide a certain reference for soil and water conservation work in Nu river basin.[Results]The results show that,the average annual rainfall of Nu river basin was 774.93 mm,and the average annual rainfall erosion force was 1 842.45[（MJ·mm）/（hm^2·h）].Among them,the rainfall changed suddenly in 1978,and the rainfall erosion force was 1966.In 1973 and 1976,the rainfall occurred,and the rainfall and rainfall erosion force in the basin showed a trend of high in the southeast and low in the northwest.The annual distribution of rainfall erosion force was mainly concentrated in summer,accounting for 48.71%,and the smallest in winter,accounting for only 5.9%.[Conclusions]The spatial distribution of rainfall and rainfall erosion force in the Nu river basin is similar,and the impact of erosive rainfall on rainfall erosion force is greater.The research results can provide a certain technical reference for soil and water conservation and ecological restoration in the Nu river basin.