西南高山峡谷区水力侵蚀时空变化及其驱动力  

Spatial-temporal Variation and Driving Mechanism of Water Erosion in Southwest Alpine-Canyon Area of China

作　　者：廖瑞恩 齐实[1,2] 赖金林 唐颖 李鹏 Liao Ruien;Qi Shi;Lai Jinlin;Tang Ying;Li Peng(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of Soil and Water Conservation,State Forestry Bureau,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]水土保持国家林业局重点实验室,北京100083

出　　处：《水土保持研究》2024年第5期139-147,共9页Research of Soil and Water Conservation

基　　金：国家重点研发计划“西南高山峡谷区水土流失综合防治技术与示范”(2022YFF1302903)。

摘　　要：[目的]确定西南高山峡谷区水力侵蚀的空间分布及其时空变化特征,探究区域水力侵蚀的驱动机制,并为区域水土流失治理提供对策。[方法]基于GIS和RUSLE模型,利用Sen趋势分析和Mann-Kendall显著性检验法、随机森林回归对西南高山峡谷区水力侵蚀的时空演变特征以及驱动力进行分析。[结果](1)西南高山峡谷区水力侵蚀微度和轻度侵蚀占比78.05%以上。(2)整体上,2000—2020年水力侵蚀量变化范围为4.606 3×10^(8)~1.487 4×10^(9) t,多年均值为7.966 4×10^(8) t。降雨侵蚀力因子变化范围为125.11~249.93 MJ·mm/(hm^(2)·h·a),多年均值为186.71 MJ·mm/(hm^(2)·h·a)。植被覆盖与管理因子变化范围为0.37~0.70,多年均值为0.48。(3)整体上坡度坡长因子对西南高山峡谷区水力侵蚀空间分异的解释程度最高,达到41%,其次是植被覆盖与管理因子,达到24%,其余是降雨侵蚀力因子>土壤可蚀性因子>水土保持措施因子,分别达到16%,12%,8%,且各因子对水力侵蚀空间分异的解释程度随着水土保持分区的不同而出现差异。[结论]西南高山峡谷区侵蚀严重的区域主要分布于藏东—川西高山峡谷生态维护水源涵养区南部,藏东南高寒高山峡谷生态维护区西北部、东部。坡度坡长因子及植被覆盖管理因子是西南高山峡谷区水力侵蚀空间分布的主要驱动因素。藏东—川西高山峡谷生态维护水源涵养区、藏东南高寒高山峡谷生态维护区和滇西北高山峡谷生态维护区,建议改善此区域植被覆盖,提高土壤抵抗侵蚀能力;滇北—川西南高山峡谷蓄水保土区建议在改善植被覆盖的基础上,在生态脆弱的区域布置适当水土保持措施。[Objective] The aims of this study are to determine the spatial distribution of water erosion and its spatial-temporal variation in southwest alpine-canyon area,to explore driving mechanism of water erosion in study area,and to provide countermeasures for regional soil erosion and water loss control.[Methods] Based on GIS and RUSLE model,the spatial and temporal variation and driving mechanism of water erosion in southwest alpine-canyon area were analyzed by using the method of the Theil-Sen trend analysis,Mann-Kendall significance test and random forest model.[Results](1) The ratio of light erosion and mild erosion was over 78.05%.(2) Generally,during the period of 2000 to 2020,the range of water erosion amount varied between 4.606 3×10^(8) t and 1.487 4×10^(9) t and the annual value was 7.966 4×10^(8) t.The range of rainfall erosion factor amount varied between 125.11 MJ·mm/(hm^(2)·h·a) and 249.93 MJ·mm/(hm^(2)·h·a) and the annual value was 186.71 MJ·mm/(hm^(2)·h·a).The range of vegetation coverage and management factor varied between 0.37 and 0.70 and the average value for years was 0.48.(3) Topographic factors was with the highest contribution to explain spatial variation of water erosion,accounting for 41%,followed by vegetation coverage and management factors,rainfall erosion factor,soil erodibility factor,soil and water conservation measure factor,accounting for 24%,16%,12%,and 8%,respectively.Moreover,spatial variation contribution of each factor varied with the soil and water conservation zone.[Conclusion] The severe erosion areas mainly distributed in the southern part of Eastern Xizang & West Sichuan Ecological Maintenance & Water Conservation Region,Eastern and northwest part of Southeast Xizang arctic-alpine Ecological Maintenance Region.Topographic factors and vegetation coverage and management factors was the main driving factors.In the Ecological Maintenance and Water Conservation Zone of Eastern Xizang & Western Sichuan,the Southeast Xizang Ecological Maintenance Arctic-alpine Zone an

关 键 词：土壤侵蚀 西南高山峡谷区 RUSLE模型 随机森林 时空变化 

分 类 号：S157.1[农业科学—土壤学]