澜沧江中下游流域土壤侵蚀时空演变特征  

Spatiotemporal Change of Soil Erosion in the Middle and Lower Reaches of Lancangjiang River

作　　者：陈晨晨 武谦[3] 张占友[3] 董卫[2] 程瑶[1,2] 王金 CHEN Chenchen;WU Qian;ZHANG Zhanyou;DONG Wei;CHENG Yao;WANG Jin(Hebei Key Laboratory of Intelligent Water Conservancy,Hebei University of Engineering,Handan,Hebei 056038,China;School of Water Conservancy and Hydroelectric Power,Hebei University of Engineering,Handan,Hebei 056038,China;Handan Zhangfu River Irrigation and Water Supply Management Office,Handan,Hebei 056001,China;Beijing Aqua Intelligent Technology Co.,Ltd.,Beijing 100070,China)

机构地区：[1]河北工程大学河北省智慧水利重点实验室,河北邯郸056038 [2]河北工程大学水利水电学院,河北邯郸056038 [3]邯郸市漳滏河灌溉供水管理处,河北邯郸056001 [4]北京湜沅科技有限公司,北京100070

出　　处：《水土保持研究》2022年第2期11-17,30,共8页Research of Soil and Water Conservation

基　　金：国家自然科学基金(U1802241);河北省创新研究群体项目(E2020402074);河北省高等学校科学技术研究项目(ZD2019005);河北省研究生创新基金(CXZZSS2021090,CXZZBS2020152)。

摘　　要：为了探究土壤侵蚀演变机制,以澜沧江中下游流域为研究区域,利用改进的土壤流失方程(RUSLE)模型,开展流域内土壤侵蚀时空演变特征研究,引入随机森林算法探讨了流域内土壤侵蚀因子的相对重要程度。结果表明:澜沧江中下游流域2005—2015年土壤侵蚀量为0~1.89万t/(km^(2)·a),平均土壤侵蚀模数为0.252万t/(km^(2)·a),中下游子流域平均土壤侵蚀模数处于较低风险以上和中风险侵蚀以下级别。自2005年以后,澜沧江中下游流域土壤侵蚀空间分布特征呈现中度侵蚀风险区域扩张,高度和低度侵蚀风险收缩的趋势。随机森林算法结果发现植被覆盖管理因子和地形因子是影响澜沧江中下游流域土壤侵蚀的主要因素,土壤可蚀性因子、降雨侵蚀因子和水土保持措施因子的相对重要程度偏低,均未超过20%。可见,土壤侵蚀的时空异质性主要是由于植被覆盖和地形影响改变了局部气候而导致的。In order to explore the evolution mechanism of soil erosion,the middle and lower reaches of Lancangjiang River was taken as the study area,the temporal and spatial evolution characteristics of soil erosion were studied by the improved RUSLE model,the relative importance of soil erosion factors was discussed by random forest(RF)algorithms.The results show that the soil erosion in the middle and lower reaches of Lancangjiang River from 2005 to 2015 ranged from 0 to 1.89×10^(4) t/(km^(2)·a),the average soil erosion modulus was 2.52×10^(3) t/(km^(2)·a);the average soil erosion moduli in the middle and lower reaches sub-basins were between the low risk and medium risk.Since 2005,the spatial distribution characteristics of soil erosion in the middle and lower reaches of Lancangjiang River showed an expanding trend in moderate erosion risk area,and shrinking trend in high and low erosion risk areas.The results of random forest algorithms indicated that cropping management factor and topography factor were the main factors affecting soil and water losses in the middle and lower reaches of Lancangjiang River,while the relative importance of soil erodibility factor,rainfall erosivity factor and support practice factor were low,all of which were less than 20%.The spatiotemporal heterogeneity of soil erosion is mainly due to the local climate changes caused by vegetation cover and topography.

关 键 词：澜沧江 中下游流域 RUSLE模型 土壤侵蚀 随机森林算法 影响因子 

分 类 号：S157.1[农业科学—土壤学]