Ornamental Evaluation Of Urban Residential Streets Greening Based On Entropy Weight TOPSIS Method

Urban road is the skeleton of a city,and the landscape greening of urban road is the only important part with vital signs in urban road infrastructure.Road greening is one of the key elements to ensure the full realization of various functions of urban road.The quality of the road greening shows the spiritual outlook and cultural level of a city,and gives the most direct external performance.Especially under the development background of "quality improvement by stock and "incremental adjustment",the renewal and reconstruction of urban roads are required to take people’s needs as the core and the matching degree of urban construction quality and residents’ needs as the standard.Therefore,road greening has become an important object of urban renewal at the present stage,and is also the research breakthrough point of landscape architecture industry for the new requirements of stock and quality improvement.On this basis,this paper uses Citespace software to draw visual knowledge maps,and finds out the distribution of road greening research at home and abroad.The research shows that the ornamental evaluation of urban greening at home and abroad mainly focuses on "large area" greening such as parks and campuses,and less attention is paid to urban street greening which involves the most complex environmental variables,especially the green space represented by life-type streets.Most of the evaluation systems constructed in part only consider plant ontology factors,but do not consider architectural color,spatial scale and other environmental factors.AHP,SD,BIB-LCJ and other evaluation methods are mostly used in the research,but the objective scientific nature of the evaluation system established by these methods cannot be verified,resulting in certain subjectivity and uncertainty of the evaluation results,so it is difficult to achieve objective quantitative research.So this study combined with the characteristics of urban roads and landscape greening,based on the theory of landscape aesthetics and visual perception,constructed an ornamental evaluation system of urban street greening,including 4 indicators and 8evaluation factors,from plant ontology factors and street environment factors.The samples of 59 life-service streets(sections)in Haikou city are studied by using entropy weight TOPSIS method and SBE method.This research will provide theoretical basis for further study on urban street greening.This study shows that:(1)The survey recorded a total of 78 species of research location road landscape plants,respectively scribe 42 genera and 23 families.There were 32 species of tree plants,accounting for 41.02% of the total.There were 19 species of shrub,accounting for 24.36%of the total.There were 27 species of flowering hedge,accounting for 34.61% of the total.There were 31 exotic plant species,accounting for 39.74% of the total.There were 47 native plant species,accounting for 60.26% of the total.In addition,these sample streets contain about 9080 trees and 3100 shrubs,and the flowering hedge is about 34,700m~2.(2)The ranking results of the entropy weight TOPSIS method and the SBE method had a high consistency,so it showed that the ornamental evaluation results of urban street greening based on the entropy weight TOPSIS method were basically consistent with the reality representation,and the quantitative evaluation results were objective and scientific.(3)The density of flowering hedge had the greatest impact on the greening of residential streets,and the planting density of trees and shrubs had the least impact.In addition,there were other factors that also had a certain influence on the greening ornamental,including morphology richness,plant species diversity,hue abundance,horizontal and vertical spatial level hierarchy of plants,and green looking ratio.(4)In general,the ornamental value of the landscaping of living streets in Haikou City is considered mediocre.In order to improve the ornamental value of greening,these suggestions are put forward in this study.Flowering hedge should be used more in streets.By planting a variety of seasonal variations of the flowering hedge,streets can create a rich spatial hierarchy.Provide large areas of flowering hedge in the streets to increase the number of green plants.At the same time,try to avoid planting a single tree or shrub.