摘要
采用经验正交函数(EOF)分析法,提取长江流域基于186个雨量站1960—2015年日降雨量计算的降雨侵蚀力时空变化特征向量,探究特征向量的时间分布和空间变化特征。分析结果表明:(1)长江流域降雨侵蚀力变化范围为114.423～16 233.136 MJ·mm/(hm^2·h),总体上从西北向东南递增,与经度和年均降水量呈正相关关系,与纬度和海拔呈负相关关系;(2)长江流域大部分地区降雨侵蚀力变化趋势具有高度一致性,下游地区降雨侵蚀力波动程度比上中游地区大;(3)长江流域降雨侵蚀力在1960—2015年间总体上以每年290.246 MJ·mm/(hm^2·h)的速率增加,在1990—2010年呈现2～5 a的周期性波动,与区域干湿交替变化相关。
Based on daily precipitation data of 186 rainfall stations of Yangtze River during the period of 1960-2015,the paper extracted the feature vector of spatial and temporal variations of calculated rainfall erosivity by using the method of empirical orthogonal function analysis( EOF) and studied its characteristics of temporal distribution and spatial variation. The outcomes show that a) the variation range of rainfall erosivity in the Yangtze River basin is from 114.423 to 16 233.136 MJ·mm/( hm^2·h),progressively increasing from the northwest to the southeast and showing positive correlations with the longitude and the mean annual precipitation and negative correlation with the latitude and the altitude; b) The variation trend of rainfall erosivity in most areas of the Yangtze River basin is highly consistent and the variability of the rainfall erosivity in the lower reaches is greater than that of the middle and upper reaches and; c) The rainfall erosivity in the Yangtze River basin increases at the rate of 290.246 MJ·mm/( hm^2·h) per year and shows 2-5 years periodic fluctuations during 1990-2010,which is associated with the regional rainfall variations.
出处
《中国水土保持》
2018年第10期37-41,共5页
Soil and Water Conservation in China
基金
国家重点研发计划项目(2017YFC1502502
2017YFC1502506)资助
长江科学院中央级公益性科研院所基本科研业务费项目(CKSF2015044/TB)
关键词
降雨侵蚀力
时空变化
EOF法
长江流域
rainfall erosivity
spatial-temporal variation
EOF
Yangtze River basin
