野外模拟降雨条件下高寒草甸区植被退化和人工植被恢复坡面的产流产沙过程  

Field Simulation of Runoff and Sand Production on Degraded and Revegetated Slopes in Alpine Meadows Under Rainfall Conditions

作　　者：甄子雲 赵洋 姜群鸥[1,2] 解晨 赵伟航 刘兰华 周铁军 何财松 周扬 ZHEN Ziyun;ZHAO Yang;JIANG Qun’ou;XIE Chen;ZHAO Weihang;LIU Lanhua;ZHOU Tiejun;HE Caisong;ZHOU Yang(School of Soil and Water,Beijing Forestry University,Beijing 100083,China;Key Laboratory of Soil and Waterand Desertification Conbating,Ministry of Education Beijing Forestry University,Beijing 100083,China;College of Resources and Environment,Xizang Agricultural and Animal Husbandry University,Lhasa 860000,China;Energy Saving and Environmental Protection and Occupational Safety and Health Research Institute,China Academy of Railway Sciences,Beijing 100081,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]北京林业大学水土保持与荒漠化防治教育部重点实验室,北京100083 [3]西藏农牧学院资源与环境学院,拉萨860000 [4]中国铁道科学研究院集团有限公司节能环保劳卫研究所,北京100081

出　　处：《水土保持学报》2024年第4期153-161,共9页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(42371291,51909052);铁路建设项目水土流失智能监测技术及应用效果研究项目(J2022Z001);国家重点研发计划项目(2019YFE0116500,2023YFF1304204)。

摘　　要：[目的]青藏高原是我国重要生态屏障,高寒草甸是其重要组成部分,水土保持功能是高寒草甸重要生态服务功能。开展青藏高原高寒草甸区水土流失过程研究对减少人为扰动水土流失、保障西南地区生态安全具有重要意义。[方法]选取青藏高原高寒草甸未退化、轻度退化、中度退化、裸坡与人工植被恢复5种不同类型坡面,通过野外模拟降雨试验,分析不同雨强条件下,不同植被退化与恢复坡面产流产沙过程,揭示植被退化与人工植被恢复坡面土壤侵蚀机理与水沙关系。[结果](1)高寒草甸未退化坡面与人工植草恢复坡面因其根系较为致密,其水分下渗能力相对较弱,故初始产流时间相对较短;而对于轻度退化坡面,侧流与纵向入渗能力相对较强,初始产流时间相对较长。(2)在常规降雨条件下(30,60 mm/h),轻度退化坡面产流量最小,减流效益最高,达到77.13%;人工恢复坡面产流量与未退化坡面接近,略高于轻度退化坡面;而裸土坡面累计产流量最大,且显著高于其他坡面;极端降雨条件下(90 mm/h)未退化坡面产流量激增,仅低于裸坡并明显高于人工植被恢复坡面。(3)在常规降雨条件下(30,60 mm/h),人工恢复植被坡面减沙效益最高,分别达到81.97%和89.82%,其次是未退化坡面,且随着植被退化程度增大,减沙效益逐渐降低;但在极端降雨条件下,人工恢复植被和未退化坡面减沙效益几乎相同,而中度退化坡面产沙量是未退化坡面的4.59倍;轻度退化坡面虽然具有较好的减流效益,但是减沙效益相对较差。[结论]研究结果可为高寒草甸区植被恢复与生态安全提供重要科学依据。[Objective]The Qinghai-Tibetan Plateau is an important ecological barrier in China,and alpine meadows are an important part of it,and the function of soil and water conservation is an important ecological service function of alpine meadows.Therefore,it is of great significance to carry out the study of soil erosion process in alpine meadows on the Tibetan Plateau to reduce anthropogenic disturbance of soil erosion and to safeguard the ecological security of the southwest region.[Methods]In this study,five different types of slopes,namely,undegraded,mildly degraded,moderately degraded,bare slopes and artificially restored slopes in alpine meadows of the Tibetan Plateau,were selected to analyze the process of flow and sand production on degraded and restored slopes under different rainfall intensities,and to reveal the relationship between the erosion mechanism and water-sand relationship between degraded slopes and restored slopes with artificial vegetation through the simulated rainfall test in the field.[Results](1)The initial flow production time is relatively short on the undegraded slopes of alpine meadows and the restored slopes with artificial vegetation because of their dense root system,and the water infiltration ability is relatively weak;while on the mildly degraded slopes,the lateral flow and vertical infiltration ability are relatively strong,and the initial flow production time is relatively long.(2)Under regular rainfall conditions(30 and 60 mm/h),the flow rate of mildly degraded slopes is the smallest,and the flow reduction benefit is the highest,reaching 77.13%,the flow rate of artificially restored slopes is close to that of undegraded slopes and is slightly higher than that of mildly degraded slopes;the cumulative flow rate of bare soil slopes is the largest,and it is significantly higher than other slopes;the flow rate of undegraded slopes under extreme rainfall conditions(90 mm/h)is surging,only lower than that of bare slopes and significantly higher than other slopes.Under extreme rainfall co

关 键 词：高寒草甸 退化草甸 水土流失 减流减沙效益 

分 类 号：S157.1[农业科学—土壤学]