Research On Ecological Restoration Strategy Of Highway Slope Landscape In Karst Area

At present,the construction of expressways is helping China's karst landform areas with foreign cooperation and regional coordinated development.However,with the rapid rise of highways,highway construction activities,such as large-scale tunneling and mountain destruction,continue to impact the fragile topography and ecological environment of the Karst landform area.Due to the high-speed operation period that lasted for several decades,the surrounding ecological environment was continuously destroyed,causing the deterioration of the ecological environment on both sides of the highway slope and the reproductive isolation of biological populations,which led to the reversal or reverse succession of vegetation.According to the Guiyang-Huishui Expressway,this paper analyzes the characteristics of the expressway slope in the Karst landform area.Through literature search and field investigation,the evaluation index and weight coefficient of the ecological restoration of the expressway slope in the Karst landform area are determined by Delphi method and analytic hierarchy process.Method and fuzzy comprehensive evaluation method,after comparing the evaluation results of the South Ring of Guiyang Ring Expressway,G321 Laziguan to Changming Highway in Guiding County,and the evaluation results of the three highways from Duyun to Anshun Expressway,the slope of expressway in Karst landform area is obtained.The factors of landscape ecological restoration have important research significance for the sustainable development of landscape ecological restoration of highway slopes in Karst landform areas.The research results show that:(1)By analyzing the types and characteristics of highway slopes in Karst landform areas,two factors are obtained.One is the internal factors: stratum and lithology;geological structure and in-situ stress;rock mass structure;primary structural plane.The second is external factors: the influence of water;weathering;topography;earthquake;human factors.Based on the above results,it can be seen that the main influencing factors of highway slopes in Karst landform areas are closely related to their geological structural conditions.Therefore,we must first analyze the geological conditions in Karst landform areas in depth and provide a solid foundation for the next step of slope landscape ecological restoration.(2)The research objects are three roads in Guizhou Province(the southern ring section of Guiyang Huancheng Expressway,the G321 Laziguan to Changming Highway Expansion Project in Guiding County,and the Duyun to Anshun Expressway),based on the results of previous literature review and field research According to the ecological effects,landscape effects,and socio-economic effects,this paper constructs an evaluation system for the ecological restoration of highway slope landscapes in Karst landform areas.There are 14 factors that affect the ecological restoration of highway slopes in Karst landform areas: species diversity,the ratio of native plants,community integrity,community stability,facade occlusion,coordination with surrounding landscape,plant coverage,landscape hierarchy,seasonal changes,slope stability,sustainability,engineering cost,civilization sign,spirit need.(3)The high-speed slope landscape ecological restoration index system in the Karst landform area is divided into two levels: three first-level indicators: ecological effects(weight: 0.5396),landscape effects(weight: 0.2970),and socio-economic effects(weight: 0.1634).14 secondary indicators: the weights from high to low are community stability 0.2607,compatibility with surrounding landscape 01868,facade obscuration 0.1424,slope stability 0.0869,species diversity 0.0765,plant coverage rate 0.0683,native plant ratio 0.0429,Sustainability 0.0400,Landscape hierarchy0.0288,Project cost 0.0208,Community integrity 0.0172,Seasonal change 0.0131,Civilization sign 0.0102,Spiritual demand 0.0053;The comprehensive evaluation of the slope landscape ecological restoration of the three research objects from high to low is Guiyang South Ring Section of Ring Expressway0.198,Duyun to Anshun Expressway 0.195,G321 Laziguan to Guiding County Changming Highway Expansion Project 0.183;Among them,the effect of ecological restoration of the slope landscape in the south ring section of Guiyang Huancheng Expressway is better,Duyun to Anshun Expressway The effect of highway slope landscape ecological restoration is relatively weak.The effect of slope landscape ecological restoration in the G321 Laziguan to Changming Highway Expansion Project in Guiding County is relatively poor.(4)By studying the concept,principles,content,goals and methods of the ecological restoration of highway slope landscape in Karst landform areas,it is concluded that: analysis and research status,establishment of an evaluation system,and basic restoration theory to restore highway slope landscape ecology in Karst landform areas.Through the above strategies,the ecological landscape of the highway slope in the Karst landform area is more complete,and the slopes of the exposed highways,rocky desertification highways and unstable geological conditions in the Karst landform areas have been repaired and improved.In order to provide a safer environment for the construction of green transportation in the Karst landform area,and promote the economic development of the entire Karst landform area which slope ecological landscape is better integrated into the natural ecological environment,presenting a hierarchical ecological landscape.(5)Taking the empirical case of Guihui Expressway slope as the research object of landscape ecological restoration,through analyzing the research status,establishing an evaluation system,and elaborating basic theories,the ecological landscape can be effectively restored.The final results show that the ecological effect,landscape effect and socio-economic effect of this demonstration road section are higher than those of Guiyang Ring Expressway South Ring,G321 Laziguan to Guiding Changming Highway Reconstruction and Expansion Project,and Duyun-Anshun Expressway,with better performance.Therefore,the research on the ecological restoration strategy of highway slope landscape in Karst landform area is reasonable and effective.This article provides a new strategy for the selection and application of the ecological restoration of expressway slope landscape in Karst landform areas.At the same time,this article provides theoretical support for the ecological restoration of expressway slope landscape in Karst landform areas.