三峡库区降雨特征和林草覆被格局对坡面水沙产出的影响  

Impacts of Rainfall Characteristics and Vegetation Cover Patterns on Slope Runoff and Sediment Yields in the Three Gorges Reservoir Area

作　　者：宋民欣 吕希恒 韩陈 韦杰[1] 唐强 贺秀斌[3] SONG Minxin;L Xiheng;HAN Chen;WEI Jie;TANG Qiang;HE Xiubin(Chongqing Observation and Research Station of Earth Surface Ecological Processes in the Three Gorges Reservoir Area,School of Geography and Tourism,Chongqing Normal University,Chongqing 401331,China;Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station,School of Geographical Sciences,Southwest University,Chongqing 400715,China;Key Laboratory of Mountain Surface Processes and Ecological Regulation,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China)

机构地区：[1]重庆师范大学地理与旅游学院,重庆市三峡库区地表生态过程野外科学观测研究站,重庆401331 [2]西南大学地理科学学院,重庆金佛山喀斯特生态系统国家野外科学观测研究站,重庆400715 [3]中国科学院、水利部成都山地灾害与环境研究所,山地表生过程与生态调控重点实验室,成都610299

出　　处：《水土保持学报》2024年第3期82-90,100,共10页Journal of Soil and Water Conservation

基　　金：重庆市杰出青年科学基金项目(cstc2021jcyj-jqX0026);西南大学先导计划青年团队项目(SWU-XDJH202306);重庆师范大学研究生科研创新项目(YKC23029)。

摘　　要：[目的]为探析三峡库区降雨特征和林草覆被格局对坡面水沙产出的影响,适应人地矛盾突出和乡村特色产业发展对林下土地资源优化利用提出的新需求。[方法]以三峡库区典型退耕林地为研究对象,设置林下全坡草本覆盖格局(QF)、上坡裸地+下坡草本覆盖格局(XF)、等高横坡草本条带覆盖格局(TF)、全坡无草本覆盖格局(WF)4种林草覆被的径流小区,开展24场侵蚀性降雨事件的坡面产流产沙野外观测,辨识降雨特征和林草覆被格局对坡面产水产沙的影响。[结果](1)24场侵蚀性降雨分为A雨型(雨量小、强度较大、历时短)、B雨型(雨量大、强度大、历时短)和C雨型(雨量小、强度小、历时长)3类。A雨型发生频率最高,为45.83%,B雨型累积降雨量最大,占总降雨量的63.44%。(2)4种林草覆被格局的累积径流深和累积侵蚀量总体呈现QF<XF<TF<WF;径流深和侵蚀量峰值均发生于B雨型,其产流量相比于A雨型增加337.74%~410.32%,产沙量增加283.47%~504.58%。(3)WF径流深和侵蚀量占比为75.75%和98.51%,XF、TF分别占12.20%和1.08%,7.28%和0.34%。与WF相比,XF和TF的径流减少84.18%和75.85%,产沙减少96.99%和93.30%。[结论]对比不同林草覆被格局的坡面水沙产出,上坡耕种+下坡草本覆盖、条带耕种+等高植物篱的林下适度利用可兼顾林地调水保土和林下生态种植的功能,为三峡库区生态修复与林下土地资源优化利用提供理论依据。[Objective]This study was aimed to explore the impacts of rainfall characteristics and vegetation cover patterns on slope hillslope runoff and sediment yields in the Three Gorges Reservoir area,and to adapt to the new needs of the prominent contradiction between man and land and the development of rural industries for the optimal utilization of underforest land resources.[Methods]Taking a typical fallow forest in the Three Gorges Reservoir area as the research object,four runoff plots with full-slope herbaceous cover(QF),upper-slope bare ground+lower-slope herbaceous cover(XF),equidistant herbaceous strip cover(TF),and full-slope herbless coverage(WF),were set up to carry out field observation of slope runoff and sand production in 24 erosive rainfall events and to identify the effects of erosive rainfall and vegetation cover patterns on hillslope runoff and sediment yields.[Results](1)The 24 erosive rainfall events were classified into three categories,including A-type(small rainfall,heavy rainfall intensity,and short duration),B-type(large rainfall,heavy rainfall intensity,and short duration),and C-type(small rainfall,light rainfall intensity,and long duration).A-type was the rain type with the highest occurrence frequency at 45.83%.The cumulative rainfall of B-type was the largest,accounting for 63.44%of the total rainfall.(2)The cumulative runoff depth and cumulative erosion volume of the four vegetation cover patterns generally showed QF<XF<TF<WF;The peak value of runoff depth and erosion volume all occurred in B-type rainfall,which led to an increase in runoff depth of 337.74%~410.32%and an increase in erosion volume of 283.47%~504.58%compared to A-type rainfall.(3)The proportion of runoff depth and erosion amount produced by the WF was 75.75%and 98.51%,while XF and TF accounted for only 12.20%and 1.08%,7.28%and 0.34%,respectively.Compared with WF,the runoff interception and reduction of XF and TF were 84.18%and 75.85%,and the sediment interception and reduction were 96.99%and 93.30%,respectively.[Conclusio

关 键 词：水土流失 侵蚀性降雨 林草覆被格局 生态修复 三峡库区 

分 类 号：S157.1[农业科学—土壤学]