| Environmental and resource problems have become one of the important fields of quaternary geology.Regional environmental geological problems,geological disaster research and prevention,and ecological environmental geology have become important research contents in applied quaternary geology.Known as "Heaven On Earth" and "Fairy Tale Kingdom",Jiuzhai Vally is a national nature reserve and AAAAA level tourist attraction in China.It is the first nature reserve in China to be built for the purpose of protecting natural scenery.It is also known internationally as a world natural heritage and the world network of biosphere reserves.The problems caused by the 7.0-magnitude Jiuzhai Vally earthquake on August 8,2017 have caused great damage to the landscape and ecology of the scenic area and had a far-reaching impact on the whole settlement,resulting in a great loss to the area's economy.Therefore,it is urgent to carry out post-disaster construction on the basis of ensuring the quality of the landscape.Based on the ecological restoration project after the 5 · 12 Earthquake in Wenchuan and the key project of Sichuan Provincial Education Department,this paper determines the research topic according to the real demand for the restoration of landslide landscape after the earthquake in Jiuzhai Vally.Based on the theory and method of quaternary geology and the information technology of remote sensing space,this study studied the factors affecting geological conditions,genetic mechanism and disaster process of Jiuzhai Vally landslide from the perspective of eco-geology-environment.Furthermore,based on vegetation restoration and landscape reconstruction,this study constructed a classification system for different types of landslides,selected species according to the site conditions of different types of landslides,and tried to establish typical geological disaster prevention and landscape reconstruction modes for different types of landslides in the scenic area.In this study,the analytic hierarchy process(AHP)and expert consultation method(Delphi)were used to comprehensively evaluate the coordination of typical restoration landslide landscape.This study combined landslide disaster prevention and landscape coordination in a scientific way to achieve the organic unity of the two,and finally realized the goal of protecting and improving the landscape.It is also the extension and practical research of applied quaternary geology based on the connotation of ecological environment discipline.Based on this,the main research contents and main conclusions and results obtained in this paper are as follows:(1)By means of remote sensing interpretation and field investigation,different disaster evaluation models are used to study the influencing factors,genetic mechanism and disaster process of landslide disaster in the scenic area.From the perspective of vegetation reconstruction,the characteristics of landslide were analyzed by using quaternary geology,restoration ecology,landscape ecology and other theories.At the same time,in connection with the domestic existing landslide ecological recovery technology,this study fully considered the site elevation,soil(lithology,weathering degree)and the 8 basic characteristics of plant growth and development elements,fully respected the geological rules of landslide,and classified the site damage landslide into six types:(1)Laohuzui landslide,(2)Heyezhai landslide,(3)Wuhuahai Lake right bank landslide,(4)Wuhuahai Lake right middle section landslide,(5)Heijiaozhai village highway landslide,(6)Unstable slope of the top of Wuhuahai lake.(2)Using historical remote sensing image and combining the field quadrat investigation and the surrounding land vegetation investigation,16 kinds of trees,20 kinds of shrubs and 12 kinds of herbs were found after a detailed study of the edificator and dominant species in different altitude regions.Their scattered distribution in Jiuzhai Vally was mastered,which has laid a certain foundation for the following species selection.(3)Based on the analysis of site conditions of six typical types of landslide,a reasonable collocation pattern was selected on the basis of selecting suitable species:Laohuzui landslide: shrub-grass-moss pattern,shrub-moss pattern,grass-moss pattern;Heyezhai landslide suitable for low vegetation: shrub-grass-moss pattern,shrub-moss pattern,grass-moss pattern;Wuhuahai lake right bank type landslide:arbor-shrub-grass-moss pattern,shrub-grass-moss pattern;Heijiaozhai village highway landslide: shady slope arbor-shrub-grass pattern,shrub-grass pattern,sunny slope arbor-grass pattern,etc;For the concave and convex,medium and low rocky soil on the gentle slopes of the highly weathered fractured structures in the middle and high mountains: the arbor-shrub-grass pattern and shady slope shrub-grass pattern,the arbor-shrub-grass pattern and sunny slope shrub-grass pattern;Unstable slopes at the top of Wuhuahai lake: shady slope arbor-grass pattern and herb pattern,sunny slope arbor-shrub-grass pattern and shrub-grass pattern and herb pattern.(4)According to the site conditions and geological characteristics of six different typical types of slopes,the prevention and control measures of landslide on the corresponding slopes are as follows:(1)Laohuzui landslide is suitable for passive protective mesh +pile-plate block wall+ micro-habitat creation(digging)+appropriate amount of soil in the hole + corresponding elevation local pioneer Joe-shrub-grass-vine-bryum pattern;(2)Heyezhai backhill type landslide is suitable for passive protective net + litter-plate block wall+ corresponding altitude local pioneer joe-shrub-grass-vine-bryum pattern+ a certain amount of soil in the hole;(3)Wuhuahai Lake right bank landslide is suitable for clear the rock + certain amount of soil filling + hanging net spraying + active protection net,corresponding altitude native vine,hole planting trees +shrub grass pioneer species pattern;(4)The middle section of the landslide on the right of Wuhuahai Lake is suitable for clear the rock +active protection net + hole planting trees + natural sowing of pioneer species of local irrigation grass at the corresponding altitude pattern;(5)Heyezhai high landslide suitable for: clear the rock + active protection net + hole planting trees + natural sowing of native irrigation grass pioneer species in corresponding elevation pattern;(6)the unstable slope at the upper end of Wuhuahai Lake is suitable for: clear the rock+ hole planting and trees + active protection net +natural seeding of pioneer species of local irrigation and grass at the corresponding altitude pattern.(5)According to the particularity of restoration landscape of post-earthquake damaged landslide vegetation in Jiuzhai Vally scenic spot,a landscape coordination evaluation system for restoration of post-earthquake damaged slope vegetation in Jiuzhai Vally scenic spot was established by combining the existing research methods of predecessors and integrating analytic hierarchy process(AHP)and expert consultation method(Delphi).The system is composed of three parts,namely,the internal coordination of landscape,the external coordination of landscape and the overall aesthetic effect.Secondly,the system gives full play to the function of the comprehensive index method,carries out relatively accurate calculation of the degree of landscape coordination,and determines the rating evaluation standard according to the specific data of the degree of coordination.Finally,six types of the typical landslide restoration pattern were evaluated using the newly built evaluation method,it is concluded that the comprehensive evaluation index(B)4.6,4.6,5.4,6,6.6,7.2,landscape coordination degree score(M)and grade(57.5,? level),respectively(57.5 and ? level),(67.5,? level),(75,? level),(82.5,? level),(90,?level).The research results show that the restoration of the vegetation of the damaged landslide in post-earthquake Jiuzhai Vally has a good coordination with the surrounding landscape. |
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