基于GIS的岷江流域降雨侵蚀力时空特征研究  

Spatial and Temporal Characteristics of Rainfall Erosivity in Minjiang River Basin

作　　者：史展[1,2] 陶和平[1] 刘斌涛[1] 郭兵[1,2] 宋春风[1,2] 

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,四川成都610041 [2]中国科学院大学,北京100049

出　　处：《水土保持通报》2013年第2期97-101,共5页Bulletin of Soil and Water Conservation

基　　金：中国科学院西部行动计划项目"西藏高原生态安全屏障监测评估方法与技术研究"(KZCX2-XB3-08);第一次全国水利普查水土保持情况普查项目"冻融侵蚀强度计算分析与制图"

摘　　要：利用岷江及周边流域124个气象水文站1981—2010年的日降雨资料计算了该区域的降雨侵蚀力。通过克吕格插值法生成降雨侵蚀力的空间分布图,采用泰森多边形和K—Means聚类法将其划分为3个等级并得到各等级的空间分布格局。根据离差系数、趋势系数和倾向率指标分析了站点年际变化特征及不同等级的时空变化格局。结果显示:(1)年均降雨侵蚀力表现出东南部高,向西迅速降低的特征,且呈现以雅安—乐山为中心向东北、西南递减缓慢,向西北递减迅速的环状空间分布格局;(2)岷江流域降雨侵蚀力聚类为侵蚀低、中、高值区,其聚类中心分别为1 054.73,4 594.50和7 153.75MJ.mm/(hm2.h.a),其中侵蚀低值区主要分布在岷江流域上游和大渡河支流流域,中值区主要分布在岷江中下游流域,高值区集中分布在岷江中游的雅安、乐山、眉山和都江堰地区;(3)降雨侵蚀力年际变化呈南北分异特征,以都江堰—汶川—小金—丹巴为界,北部变化大于南部,变化趋势呈东西分异特征,以茂县—理县—汶川—宝兴—天全—汉源—峨边—沐川—宜宾一线以东呈下降趋势,以西呈上升趋势。不同地区的降雨侵蚀力变化趋势的显著程度也不同。In order to analyze the spatial distribution and temporal change of rainfall erosivity in Minjiang River Basin, rainfall erosivity was calculated using daily data from 124 stations during 1981-2010. Its spatial distribution map was created by Kriging interpolation. Based on Thiessen polygons theory and K-Means cluster method, we divided the rainfall erosivity into three classes and analyzed the deviation coefficient, tendency coefficient and trend rate of each class. The results showed that annual rainfall erosivity was high in southeast and lowered rapidly towards west. The rainfall erosivity was divided into three classes with cluster center of 1 054.73, 4 594.50 and 7 153.75 MJ · mm/（hm^2 · h · a） respectively. The area of low values was mainly located in the upstream of the basin and its branch Dadu River basin, the area of intermediate values was mainly located in middle and lower reaches, and the high value area was found mainly in the regions of Ya＇an, Leshan, Meishan and Dujiang weirs. The inter-annual variability differed spatially~ more variations were found in northern area than in southern area, as divided by the transect of Dujiangyan Wenchuan-- Xiaojin--Danba. Increasing inter-annual variability was found in the western part, whereas decreasing varia- bility in the eastern part. The significance levels of changing trends differed spatially.

关 键 词：降雨侵蚀力 岷江流域 空间分布 变化趋势 

分 类 号：P954[天文地球—自然地理学]