雅鲁藏布江米林段小流域土壤侵蚀特征  

Soil Erosion Characteristics at Small Watersheds Along Milin Region in the Yarlung Tsangpo River

作　　者：陈豪爽 兰玲 王协康[1] CHEN Haoshuang;LAN Ling;WANG Xiekang(State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学山区河流保护与治理全国重点实验室,四川成都610065

出　　处：《工程科学与技术》2025年第2期115-124,共10页Advanced Engineering Sciences

基　　金：国家自然科学基金重点项目(52239006);国家自然科学基金委员会-中华人民共和国水利部-中国长江三峡集团有限公司长江水科学研究联合基金项目(U2340201);四川省自然科学基金项目(2024NSFSC0005)。

摘　　要：雅鲁藏布江是中国最长的高原河流,水资源丰富,但沿岸土壤侵蚀严重,滑坡、泥石流灾害频发,生态环境脆弱,影响着流域的水电开发,因此,揭示其土壤侵蚀特征对于水资源管理与水电开发具有重要意义。本文采用修正通用土壤流失方程(RUSLE)模型,开展了雅鲁藏布江流域米林段12条典型小流域多年土壤侵蚀演化的定量研究,并分析了地震前后的侵蚀特征。结合地理探测器探究了米林段小流域的土壤侵蚀驱动因子,分析了多因子交互作用对土壤侵蚀的影响,并探讨了研究区土壤侵蚀的风险区域。结果表明:1)研究区主要发生微度和轻度侵蚀,其中:多空普、鲁霞普曲、丹娘沟年平均侵蚀量均超过3×10^(5) t,生态环境脆弱;门着普沟、蹦嘎沟、曲鲁沟、额阿东沟多年平均侵蚀量均不超过105 t。2)地震加剧了流域土壤侵蚀。地震前,气候条件与植被覆盖相互作用,使土壤侵蚀总体呈下降趋势;地震后,降雨侵蚀阈值降低,温度影响加强,流域对气候变化更为敏感。3)植被覆盖是主要的驱动力因子,其与地形、气候的交互作用主导土壤侵蚀;坡度与其他因素交互作用的影响最显著。4)裸地与归一化差异植被指数(NDVI)小于0.41的区域是流域土壤侵蚀的主要风险区。地震后,裸地的土壤侵蚀模数增加56.88 t·km^(-2)·a^(-1),NDVI范围为0.05至0.14区域的土壤侵蚀模数达到103.46 t·km^(-2)·a^(-1)。研究成果可丰富现有对雅鲁藏布江流域土壤侵蚀特征的认识,为水电开发与水土保持政策提供科学依据。Objective The Yarlung Tsangpo River,China’s longest highland river,possesses substantial water resources.Despite its significance,the river faces critical environmental challenges,including severe soil erosion,frequent landslides,and mudslides.These natural disturbances contribute to sediment siltation and riverbed blockages,undermining the river’s ecological integrity and hindering sustainable hydropower development in the basin.This study plays a critical role in analyzing soil erosion dynamics,which are essential for effective water resource management and strategic hydropower planning by emphasizing the urgency of addressing these environmental issues.Methods This research utilized the RUSLE model to quantify soil erosion processes in 12 representative sub-watersheds of the Yarlung Tsangpo River’s Milin section,specifically focusing on the changes in erosion patterns before and after a significant earthquake.It employed a geo-detector approach to identify the primary drivers of soil erosion within these sub-watersheds.Through a comprehensive analysis of multiple interacting factors,the research clarified the complex mechanisms driving soil erosion and determined high-risk areas,guiding targeted interventions to strengthen the ecological resilience of the region against ongoing and future environmental challenges.Results and Discussions The results showed that the LS factor distribution indicates the study area’s high altitude and significant topographic relief C factor values between 0.35 and 0.45 revealed poorer vegetation cover on high-altitude ridges and better cover at lower altitudes.K values ranged from 0 to 0.1025,indicating lower soil erodibility at lower altitudes and higher erodibility at ridges.P values decreased from 2001 to 2016 and then increased after 2016.Rainfall erosivity showed a general downward trend,with fluctuations from 2008 to 2010.It was lower in high-altitude areas and stronger at lower elevations.From 2001 to 2020,the study area experienced an average soil erosion rate of 3

关 键 词：土壤侵蚀 地理探测器 雅鲁藏布江 时空演变 

分 类 号：TV141.3[水利工程—水力学及河流动力学]