Ecological Protection Benefits Of Plant Fiber Blankets On Trench Slopes In Loess Hilly-Gully Region

In order to explore the applicability of the plant fiber blanket slope protection measures in the loess hilly and gully region,and the soil and water conservation benefits of the plant fiber blanket slope protection measures,this article uses Duanlanyao drainage slope,Qingshuihe County,Hohhot,Inner Mongoliaas a research area,field community monitoring and field artificial simulated rainfall test as the research,monitoring the plant growth status,species diversity and surface soil physical and chemical properties of the slope after laying plant fiber blanket,and measuring the runoff time of the plant fiber blanket covering slope under different rainfall intensity and different plant growth period,Runoff and sediment yield,comprehensively analyze and evaluate the ecological slope protection benefits of plant fiber blanket slope protection measures in the loess hilly and gully area,with a view to providing scientific basis and theoretical reference for the study of soil erosion laws and control of soil and water loss in the loess hilly and gully area.Thee conclusions are as follow.(1)The plant fiber blanket slope protection measures have a certain promotion effect on plant growth.Compared with the direct seeding grass slope protection measures,the plant fiber blanket slope protection measures can further increase the coverage and height of the slope vegetation,and the coverage and height can be increased compared to the direct seeding grass slope protection measures 3.33%and 4.72cm,and the species diversity of plant fiber blanket slope protection measures is also the highest,of which Shannon-Wiener diversity index reaches 2.65,Margalef richness index reaches 2.44,and Pielou evenness index reaches 1.23.(2)The slope protection measures of plant fiber blankets can improve the slope soil.After covering the plant fiber blankets,the soil moisture content,total porosity,total nitrogen content,and organic matter content of the surface soil of the slope are significantly higher than those of the bare slopes,and they are increased compared to the bare slopes 46.81%,29.07%,50.11%and 56.77%.(3)Under different rainfall intensities,the plant fiber blanket slope protection measures have good flow reduction and sediment reduction benefits,with an average flow reduction benefit of 63.73%and an average sediment reduction benefit of 76.59%;both the flow reduction and sediment reduction benefits are at the rainfall intensity.It is the highest at 30mm/h,but with increasing rainfall intensity,the benefits of flow reduction and sediment reduction are reduced to varying degrees.(4)Under different plant growing seasons,the plant fiber blanket slope protection measures also have good flow reduction and sediment reduction benefits,with an average flow reduction benefit of 68.46%and an average sediment reduction benefit of 81.64%.The plant growth period was the highest at 132 days.As the plant growth period increased,the benefits of flow reduction and sand reduction increased to varying degrees.(5)The vegetation height and coverage of the slope are the main factors affecting the runoff and sand production of plant fiber blanket slope protection measures in vegetation growth conditions.Runoff,sediment production and the height and coverage have a multivariate linear function relationship,satisfying y=a-bx1-cx2(y is the runoff(mL)or sediment yield(g),x1 is the height(cm),and x2 is the coverage(%)).(6)From the analysis of grey correlation,in the loess hilly and gully area,the protection effect of the plant fiber blanket slope protection measures on slopes is better than the direct-seeded herbal slope protection measures.