Evaluation Of Slope Revegetation Effectiveness And Influencing Factors In Yangtze River Basin

With the development of China’s economy and the rapid expansion of the scale of infrastructure projects,the restoration technology and effect evaluation of various slopes are attracting more and more attention.At present,there are relatively few researches on the effect of slope vegetation restoration,mostly for a specific location or project,and there is a lack of standards and guidelines for the evaluation of slope vegetation restoration effect.Therefore,it is important to establish a more general evaluate index system for the evaluation of slope vegetation restoration effect and explore the key factors affecting slope vegetation restoration for both practice and research of slope vegetation restoration.This paper takes typical slopes in the Yangtze River basin and its surrounding areas as the research object,determines the weights of evaluation indexes by using analytic hierarchy process based on field survey and the construction of slope vegetation restoration effect evaluation index system,and evaluates the restoration effect of selected typical slopes by combining the comprehensive index method from community restoration and slope stability,and analyzes the effect of five common spraying substrates on the early restoration effect of slopes.The effects of five common spraying substrates on the early restoration effect of slopes were also analyzed.The main results of the study are as follows:(1)An index system for evaluating the effectiveness of slope vegetation restoration in the Yangtze River basin with B1 plant community(0.667)and B2 slope stability(0.333)as criterion layers was constructed.The indicators and weights under the criterion layer B1 were C1 vegetation cover(0.144),C2 vertical structure level of vegetation(0.142),C3 species conservation rate(0.117),C4 slope vegetation health(0.088),C5 green period(0.069),C6 native proportion of invasive species(0.055),C7 invasive species(0.034),C8 plant species richness(0.018);the indicators and weights under criterion layer B2 were C9 slope flatness(0.088),C10 substrate integrity(0.076),C11 slope erosion resistance(0.088),C12 drainage system integrity(0.053),and C13 support facilities integrity(0.028).(2)among the investigated slopes,the slopes with "excellent" vegetation recovery account for 8%,the slopes with "good" vegetation recovery account for 54%,the slopes with "medium" vegetation recovery account for 23%,and the slopes with "poor" vegetation recovery account for 15%.The proportion of "poor" slopes is 15%,and all the slopes with "poor" slopes are rock slopes.(3)the main factors that affect the slope restoration effect include slope type,slope,sowing sequence,sowing proportion of native tree species,engineering measures,restoration time and substrate type.The higher the rock content,the worse the vegetation restoration effect.The greater the slope,the worse the effect of vegetation restoration.When herb shrub sowing sequence is adopted,the effect of vegetation restoration is better than that of sowing at the same time.With the increase of the proportion of native tree species at the early stage of sowing,the better the effect of slope vegetation restoration.In the revegetation of medium and high slopes,the use of additional reinforced concrete structures for slope reinforcement is more conducive to slope revegetation.With the increase of restoration years,the better the restoration effect of slope vegetation.The better the effect of slope vegetation restoration,the key period of slope vegetation restoration is 3 to 5 years after slope restoration.BSM is the most beneficial to the growth of early plant,followed by grass fiber,wood fiber and FGM,and pulp is the worst.