摘要
[目的]探究生物结皮对坡面流水动力特征的影响,为黄土高原丘陵区生物结皮防蚀机理研究提供理论指导。[方法]设置生物结皮覆盖及破坏处理,进行人工模拟降雨试验。[结果]①生物结皮覆盖及破坏处理下坡面流均属于层流急流。②生物结皮可显著降低坡面流流速,增加水流剪切力,阻力系数和水流功率(p<0.05)。其中,藻结皮处理和苔藓结皮处理较裸地流速分别减少了48.74%和62.24%,水流剪切力、阻力系数、水流功率较裸地分别增加了130.01%和308.07%;703.35%和2532.01%;21.16%和57.43%。③生物结皮破坏后其阻力系数与裸地无显著变化,流速、水流剪切力、水流功率均显著高于裸地(p<0.05)。其中,藻结皮破坏和苔藓结皮破坏处理较裸地流速、水流剪切力、水流功率分别增加了10.84%和16.46%;36.83%和42.44%;60.90%和62.14%。[结论]生物结皮覆盖会增大坡面流阻力系数,降低流速。生物结皮破坏后坡面流阻力系数与裸地无差异,流速增加。此外,生物结皮覆盖及破坏处理均会增大坡面流水流剪切力及水流功率,进而增加径流侵蚀能量。
[Objective]The effects of biological soil crusts(biocrusts)on the hydrodynamic characteristics of slope flow were investigated in order to provide theoretical guidance for the study of biocrusts anti-erosive mechanism in hilly regions of the Loess Plateau.[Methods]The treatments of biocrusts coverage and destruction were set,and the artificial rainfall simulation experiments were conducted in this study.[Results]①The slope flow of biocrusts coverage and destruction treatments was the laminar jet stream.②The biocrusts coverage significantly reduced slope velocity,whereas increased shear stress,resistance coefficient,and stream power(p<0.05).Compared with the bare land,the slope velocity of algal crust and moss crust treatment decreased by 48.74%and 62.24%.The shear force,resistance coefficient,and stream power increased by 130.01%and 308.07%,703.35%and 2532.01%,21.16%and 57.43%,respectively.③Compared with the bare land,the resistance coefficient was no significant difference after the biocrusts were destroyed,whereas the flow velocity,shear stress,and stream power were significantly higher than the bare land(p<0.05).The slope velocity,shear stress,and stream power of the algae crust and moss crust treatments increased by 10.84%and 16.46%,36.8%and 42.44%,60.8 and 62.14%,respectively.[Conclusion]The biocrusts coverage increased slope flow resistance coefficient and decreased flow velocity.After the biocrusts were destroyed,the slope flow resistance coefficient was no different from the bare land,but the flow velocity increased.Furthermore,the biocrusts coverage and destruction treatment increased shear force and stream power of the slope flow,thereby increasing the runoff erosion energy.
作者
张慧妮
王兵
张宝琦
韩剑桥
许欢欢
Zhang Huini;Wang Bing;Zhang Baoqi;Han Jianqiao;Xu Huanhuan(State Key Laboratory of Soil Erosion and Dryland Agriculture on the Loess Plateau,Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;University of Chinese Academy of Science,Beijing 100049,China;Supervision Bureau of Soil and Water Conservation,Xifeng Governance,Qingyang,Gansu 745000,China)
出处
《水土保持通报》
CSCD
北大核心
2022年第2期16-21,共6页
Bulletin of Soil and Water Conservation
基金
中国科学院“西部之光”西部青年学者A类项目“黄土高原退耕草地近地表特征变化及其对土壤侵蚀过程的影响”(XAB2019A04)
国家自然科学基金重点项目“黄土高原刺槐人工林结构与生态功能相互作用机制及调控”(42130717)。
关键词
生物结皮
藻结皮
苔藓结皮
水动力学
结皮破坏
biological soil crusts
algae crust
moss crust
hydrodynamics
biocrusts destruction
