黄土丘陵区坡面植被盖度及其配置格局的水蚀效应模拟  

Simulation of the effect of slope vegetation cover and allocation pattern on water erosion in the loess hilly region

作　　者：任柯蒙 卫伟[1] 赵西宁[3,4] 冯天骄 陈蝶 于洋[1,6] REN Kemeng;WEI Wei;ZHAO Xining;FENG Tianjiao;CHEN Die;YU Yang(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences ,Beijing100085,China;Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling 712100,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,China;Institute of Soil and Water Conservation,Chinese Academy ofScienees &Ministry of Water Resources,Yangling 712100,China;School of Resources and Environment,University of Chinese Academy of Sciences,Beijing 100049,China;Department of Sediment Research,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国科学院生态环境研究中心城市与区域生态国家重点实验室,北京100085 [2]西北农林科技大学旱区农业水土工程教育部重点实验室,杨凌712100 [3]西北农林科技大学水土保持研究所,杨凌712100 [4]中国科学院水利部水土保持研究所,杨凌712100 [5]中国科学院大学资源与环境学院,北京100049 [6]中国水利水电科学研究院泥沙研究所,北京100048

出　　处：《生态学报》2018年第22期8031-8039,共9页Acta Ecologica Sinica

基　　金：国家重点研发计划(2016YFC0501701);国家自然科学基金项目(41390462;41371123);中国科学院青年创新促进会项目;中国林科院面上项目(CAFYBB2017MB039)

摘　　要：黄土高原因土壤侵蚀严重被视为生态脆弱地带,探讨植被盖度及其所处坡位对土壤侵蚀的响应,对坡面侵蚀产沙的预测和调控具有重要意义。基于WEPP模型情景模拟,分析了分布广泛、耐旱性强的长芒草和典型恢复灌木植被柠条在不同雨强(0.5、1.0、1.5 mm/min)、不同植被盖度(20%、40%、60%、80%)和不同坡位(坡上、坡中、坡下)条件下的土壤侵蚀变化情况,运用双因素方差分析和相关贡献指数阐明坡面侵蚀产沙特征对坡位和植被盖度交互作用的响应,并提出植被配置的优化模式。结果表明:(1)提高植被有效覆盖度是减小土壤侵蚀的重要举措,且当植被分布在下坡位时坡面土壤侵蚀最少;(2)植被盖度可以有效减少产沙量。小雨强时,柠条和长芒草随盖度增加对泥沙的拦截率分别从38%增加到90%,64%增加到96%;中、大雨强时,植被盖度小于20%或者大于80%时,长芒草坡面产沙量大于柠条坡面。盖度为40%—60%时,长芒草坡面产沙量小于柠条坡面;(3)双因素方差分析表明:坡位和植被盖度对坡面侵蚀产沙量有极显著的影响(P<0.001);当植被是长芒草时,坡位和植被盖度交互作用对坡面侵蚀产沙有显著影响(P<0.01),植被是柠条时,坡位和植被盖度交互作用对坡面侵蚀产沙作用不显著;(4)通过模拟柠条和长芒草不同配置情景得出:长芒草分布在坡面下部产沙量较小,且当柠条和长芒草配比为1∶2时产沙量最小。Owing to severe erosion,ecosystems in the Loess Plateau in China are regarded as the most fragile habitats globally. Therefore,it is fundamental to explore the response of water erosion dynamics to vegetation cover and slope allocation,aiming at the accurate prediction and control of sediment yield. In the present study,the WEPP( Water Erosion Prediction Project) model was used to simulate the rainfall-erosion process at a hillslope scale,and the changing processes of soil erosion under different rainfall intensities( 0.5,1.0,1.5 mm/min),vegetation canopy cover( 20%,40%,60%,80%),and slope position( upper,middle,lower) were analyzed. The responses of sediment yield to the interaction effects of vegetation canopy cover and slope positions were revealed by a double factor variance analysis and relative contribution index. The results showed that an increase of vegetation canopy cover reduced soil loss and sediment yield significantly,and the least soil loss occurred when the vegetation was distributed in the lower slope conditions. At a low( 0. 5 mm/min)rainfall intensity,with increased vegetation canopy cover,the interception rate of sediment of Caragana and Stipa bungeana increased from 38% to 90% and 64% to 96%,respectively. At medium( 1.0 mm/min) and high rainfall( 1.5 mm/min)intensities,when the vegetation canopy cover was < 20% or > 80%,the sediment yield of the S. bungeana slope was greater than that of the Caragana slope. However,when the vegetation canopy cover was between 40% to 60%,the sediment yield of the S. bungeana slope was less than that of the Caragana slope. Meanwhile,a double factor variance analysis showed that slope position and vegetation cover exhibited a significant effect on sediment yield on slopes( P <0.001). Specifically,the interaction between the slope position and S. bungeana vegetation cover showed a significant effect on sediment yield( P < 0.01),but when the vegetation changed to Caragana,the interaction between slope position and vegetation cover became insignificant on sediment y

关 键 词：植被盖度 坡位 产沙量 植被配置 

分 类 号：S157.1[农业科学—土壤学]