岷江上游流域土壤侵蚀风险评估

针对岷江上游流域侵蚀现状、特点, 在拟定评价指标的基础上, 运用 GIS 加权叠加分析法探究了岷江上游流域 侵蚀风险, 得出如下结论: ( 1) 陡坡占 611 20% , 年均降雨量差异较大, 土壤土质疏松绵软, 地震影响强度高; ( 2) 中度 以上侵蚀风险比例为 891 31 % , 土壤侵蚀形势严峻; ( 3) 中度侵蚀风险区主要分布在水网附近, 与土地利用类型以及 人类生产生活密切相关; 重度风险区主要分布在岷江上游流域的西部、西南部和南部周边地区, 与/ 5 # 120 汶川特大 地震密切相关; ( 4) 汶川、理县为重度风险侵蚀关键治理区, 黑水、茂县、松潘为中度侵蚀风险治理区。 Acco rding to the curr ent situation and characteristics o f soil erosio n in t he upper reaches of Minjiang River, after deter2 mining the assessment index es, w e used the metho d o f Weig hted Superposit ion Analysis to ex plor e the ero sion risk. T he r esults are as follow s: ( 1) In t he upper r eaches of Minjiang River, steep slo pes make up 611 20% of the area; annual r ainfa ll v aries sig2 nificantly; the so il is loo se and soft; the impact o f earthquake is stro ng . ( 2) The r atio of moderate and above ero sion risk w as 891 31% in the study ar ea, indicating a serious so il ero sion situat ion. ( 3) T he moderate risk areas a re mainly distributed near the water netw or k, and ar e closely related to land use t ypes and human activit ies; the hig h risk areas ar e mainly distributed in the west, so uthw est and so ut h of the upper reaches of Minjiang River, and are clo sely co nnected w ith the Wenchuan Earthquake. ( 4) Wenchuan County and Lixian County ar e key manag ement r egions of hig h erosion risk, and H eishui County , Maox ian Count y, and Songpan Co unty a re manag ement reg ions of moderate er osion risk. 四川省教育厅/ 农村水安全0四川省高等学校工程研究中心项目( 035Z1502)