2007—2020年白沙河流域土壤水力侵蚀时空变化  

Spatial and Temporal Changes in Soil Water Erosion in Baisha River Basin from 2007 to 2020

作　　者：谢航宇 江怡 陈麒 鲍玉海[1] 胡云华 贺秀斌[1] Xie Hangyu;Jiang Yi;Chen Qi;BaoYuhai;HuYunhua;He Xiubin(Institute of Mountain Haxards and Environment,Chinese Academy of Sciences and Ministry of Water Resources,Chengdu,Sichuan 610041,China;University of Chinese Academy of Sciences Beijing 100049,China;Chengdu Technology Center of Water AfairsChengdu,Sichuan 610041,China;Sixth Topographic Suruey Team of theMinistry of Natural Resoures,Chengdu,Sichuan 610500 China)

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 [3]成都市水务技术中心,四川成都610041 [4]自然资源部第六地形测量队,四川成都610500

出　　处：《水土保持通报》2022年第4期74-81,89,共9页Bulletin of Soil and Water Conservation

基　　金：四川省区域创新合作研究项目“川渝地区陡坡耕地禁垦坡度诊断方法与坡耕地综合治理技术研究”(2020YFQ0002);成都市水土保持监测分站政采项目“成都市中心城区水源地白沙河流域水土流失综合防治体系研究”(5101012019001908)。

摘　　要：[目的]研究四川省都江堰市白沙河流域地震前后土壤水力侵蚀时空变化规律,为地震灾区水源地保护和土壤侵蚀防治工作提供科学参考。[方法]利用中国土壤流失方程CSLE(chinese soil loss equation)定量分析了2007—2020年白沙河流域土壤水力侵蚀面积、强度、空间分布特征。[结果](1)地震后流域水力侵蚀强度等级整体呈现先升高再降低的趋势,2007,2008,2013,2018,2020年土壤侵蚀模数分别为817.51,3000.11,5828.89,1549.76,1558.37 t/(km^(2)·a),2020年土壤侵蚀强度下降到以轻度侵蚀为主,平均土壤侵蚀模数相比2008年降低了48.1%。(2)坡度35°以上和海拔2000 m以上区域贡献的土壤侵蚀量分别占2020年总量的85.44%,68.20%,平均土壤侵蚀模数超过5000 t/(km^(2)·a)的强烈及以上强度侵蚀主要发生在海拔4000 m以上的地区。(3)震后10 a来,虽然白沙河流域平均植被覆盖度在60%~74%之间,但中度及以上强度侵蚀面积相较于地震前仍呈现较高比例,2020年中度及以上强度侵蚀面积比例是地震前2007年的4.13倍。[结论]随着自然恢复年限的增加,2013—2020年白沙河流域土壤水力侵蚀状况得到有效改善,但流域中上游局部地区仍存在强烈及以上强度侵蚀,地形条件和降雨侵蚀力对其变化影响作用明显。[Objective] The spatial-temporal variations of soil water erosion before and after the Wenchuan earthquake in the Baisha River basin of Dujiangyan City, Sichuan Province were assessed to support water source protection efforts and comprehensive control of soil erosion in the earthquake-stricken area. [Methods] The characteristics of soil water erosion(i. e., area, intensity, and spatial distribution) in the Baisha River basin from 2007 to 2020 were quantitatively analyzed by using the Chinese Soil Loss Equation(CSLE). [Results](1) The intensity of soil water erosion after the Wenchuan earthquake in the Baisha River basin initially increased and then decreased. The average soil erosion modulus values for the Baisha River asin were 817.51, 3 000.11, 5 828.89, 1 549.76, and 1 558.37 t/(km^(2)·a) in 2007, 2008, 2013, 2018, and 2020, respectively. The intensity of soil erosion in 2020 was mainly classified as light erosion, and the average soil erosion modulus was 48.1% lower than in 2008.(2) The average soil erosion modulus gradually increased with increasing slope gradient or altitude. Soil erosion amount contributed by regions with slope greater than 35° and elevation above 2 000 m accounted for 85.44% and 68.20%, respectively, of the total erosion amount in 2020. In addition, the extremely severe erosion area with an average soil erosion modulus of more than 5 000 t/(km^(2)·a) mainly occurred in areas with elevation above 4 000 m.(3) Although the average vegetation coverage in the Baisha River basin in the past 10 years was between 60% and 74%, the proportion of the area classified as having moderate and more severe erosion was still greater than before the earthquake. In 2020, the proportion of moderate and more severe erosion area was 4.13 times greater than in 2007. [Conclusion] Even though the soil water erosion situation has effectively improved between 2013 and 2020, areas of intense and more severe erosion remain in the middle and upper reaches of the study area, and the topographic conditions and rainfa

关 键 词：土壤侵蚀 CSLE 白沙河流域 时空变化 汶川地震 四川省都江堰市 

分 类 号：S157.1[农业科学—土壤学]