An Empirical Study On Near-natural Slope Regulation Model In Qinba Mountain Area

Soil and water loss on slope have been the biggest problem in ecological environment restoration in Qinling-Daba mountain area.In traditional slope remediation,there are widespread problems such as high project cost,high maintenance cost and material environmental pollution.With the rise of "ecological engineering","near-natural" ecological theory and technology has become an important development direction for soil and water remediation.However,in terms of the intensity,frequency and cost of treatment,the traditional soil and water conservation measures for slopes in China have deviated from the idea of "near-natural" ecological treatment.In addition,theoretical research and technical discussions on "nearnatural" soil and water remediation are almost absent in the field of soil and water conservation.How to integrate the "near-natural" ecological theory and technology into the slope soil and water remediation measures in practice is a key research and discussion issue for soil and water conservation in the new era.(1)The paper summarises the concept of "near-natural" from its inception to its evolution and application,and proposes the concept of "near-natural slope remediation" and identifies it with the concepts related to soil and water conservation.Near-natural slope remediation refers to a mode of slope erosion management that follows the laws of natural development,selects environmentally friendly,natural and suitable remediation materials,and maintains the maximum natural landscape and ecological management on the basis of erosion control and nutrient conservation.(2)According to the principle of nearness to nature,the evaluation system of optimal nearness to nature slope remediation mode allocation scheme in Qinling-Ba mountain area was constructed.The economic benefit of nearness to nature slope remediation,plant characteristics of nearness to nature slope remediation,ecological benefit of nearness to nature slope remediation,engineering benefit of nearness to nature slope plant and nearness degree of materials were five evaluation criteria.The best configuration scheme of the near-natural slope regulation mode in Qinba mountain area was determined as follows: hexagonal lattice revetment,planting plum at the top of the slope,paeonia alba at the bottom,planting tea tree at the ridge,planting ryegrass on the ridge slope.(3)based on soil physical and chemical properties,soil corrosion resistant properties,soil shearing properties research shows that after nearly natural slope regulation mode of slope in the physical and chemical properties,corrosion resistance,shearing resistance are much better than not governance slope,soil and water retention has been greatly improved and close to the natural slope stability index is greater than the control group(1.13 > 0.21);The main factors affecting the stability of slope are soil erosion resistance index,soil physical and chemical properties index and shear resistance index have a relatively small impact.After treatment,there is no soil erosion and soil collapse phenomenon on the slope,and it plays a role in greening the environment,so the near-nature mode of slope is better.The slope stability of near-natural mode regulation decreases with the increase of soil layer,so the stability of soil layer at 20-40 cm depth should be paid more attention to.