狗牙根覆盖对三峡库区消落带波浪作用力和侵蚀的影响  

Influence of Cynodon dactylon cover on the wave force and wave erosion of purple soil in the water-level-fluctuating zone of the Three Gorges Reservoir

作　　者：肖海 张文琪[1] 夏振尧 刘子睿[1] 张伦 杨悦舒 崔磊 XIAO Hai;ZHANG Wenqi;XIA Zhenyao;LIU Zirui;ZHANG Lun;YANG Yueshu;CUI Lei(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area(China Three Gorges University),Ministry of Education,443002,Yichang,Hubei,China;College of Civil Engineering&Architecture,China Three Gorges University,443002,Yichang,Hubei,China;China Renewable Energy Engineering Institute,100120,Beijing,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室,湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002 [3]水电水利规划设计总院,北京100120

出　　处：《中国水土保持科学》2024年第4期34-40,共7页Science of Soil and Water Conservation

基　　金：国家自然科学基金区域创新联合基金重点支持项目“鄂西山区大型水库复活型滑坡侵蚀致灾机制与生态防控”(U21A2031);国家自然基金青年科学基金“基于稀土元素示踪的植物篱对三峡库区坡耕地侵蚀-沉积分布的影响机制”(41807068);中国三峡建设管理有限公司科研项目“白鹤滩水电站工程干热河谷区土壤改良、植物优选、边坡生态恢复技术应用研究”(BHT/0869)和土木工程防灾减灾湖北省引智创新示范基地(2021EJD026)。

摘　　要：波浪侵蚀是三峡库区消落带土壤侵蚀的主要类型,已严重威胁到库区经济发展和生态环境构建。植被修复可以实现水土保持和增强消落带稳定性目的,但关于在波浪作用于消落带上坡面时植物覆盖对波压力和孔隙水压力和侵蚀量的影响及关系尚不明确。为此,设置3个波高(4、6和8 cm)、3个坡面条件(裸坡对照、30%狗牙根覆盖和60%狗牙根覆盖),开展模拟波浪试验,分析不同植被盖度对消落带波浪作用力和侵蚀的影响。结果表明:裸坡时,随波高增加,波压力和孔隙水压力分别增加3.80%~48.62%和13.12%~50.44%,侵蚀量增加0.88%~8.08%。存在植被时,对比裸坡,随波高增加,波压力和孔隙水压力分别降低2.98%~220.17%和15.47%~75.64%,侵蚀量则降低29.31%~80.83%。植物可以通过地上部分和地下部分消散波压力和孔隙水压力,从而提高消落带受波浪作用的耐受性,进而有效降低波浪造成的侵蚀量。以上结果加深了在波浪作用于紫色土消落带坡面时狗牙根覆盖与波浪作用力与侵蚀量关系的理解,为库区消落带植被恢复和水土保持提供一定的参考。[Background]Wave erosion is the main type of soil erosion in the water-level-fluctuating zone(WLFZ)of the Three Gorges Reservoir(TGR),the disasters such as soil erosion and landslide caused by wave erosion are becoming more and more serious,which have seriously threatened the local economic development and ecological environment construction around the reservoir area.In addition,vegetation restoration can meet the goals of soil and water conservation and soil erosion and enhancing the slope stability in the WLFZ.However,the effects of plants on the wave pressure,pore water pressure and erosion caused by waves and their relationships remains largely unexplored.[Methods]The typical plant and soil of Cynodon dactylon and purple soil in the WLFZ of the TGR was used as the research object.Three slope conditions with bare as CK,coverage of 30%by C.dactylon and coverage of 60%by C.dactylon were formed for simulated wave test with wave heights of 4,6 and 8 cm.The wave pressure,pore water pressure was monitored by mechanical sensors on the surface of the slope and within the slope during the test.And the wave erosion for each test was also measured by drying method.Then the influence of C.Dactylon cover on the wave pressure,pore water pressure and wave erosion of purple soil in the WLFZ were evaluated by statistical analysis.[Results]The wave pressure,pore water pressure and wave erosion affected by the cover rate of C.dactylon and the wave height.The wave pressure,pore water pressure and wave erosion increased by 3.80%-48.62%,13.12%-50.44%and 0.88%-8.08%with the increase of wave height when the slope condition was bare,respectively.And the wave pressure,pore water pressure and wave erosion decreased by 2.98%-220.17%,15.47%-75.64%and 29.31%-80.83%with the cover of C.Dactylon,respectively,when compared with the bare condition.Correlation analysis showed that the wave erosion was significantly negatively correlated with the C.dactylon coverage(P<0.01),and was significantly positively correlated with sensor 4#and 5#wave pres

关 键 词：狗牙根 波浪 波压力 孔隙水压力 波浪侵蚀 

分 类 号：S157.1[农业科学—土壤学]