Research On Green View Index Analysis And Promotion Design Of Tai’an Historic Urban Area

In the context of green and low-carbon urban development and humanized transformation of street space,how to realize scientific and efficient afforestation in the limited street space and create an ecological green street environment has become a hot topic in the field of landscape architecture and related research.Based on people’s psychological perception of the environment,Green View Index visually presents the three-dimensional green quantity of street space through indicators.At the same time,the rapid development of new technologies such as network street view and image recognition has widened the application scope of Green View Index.From the perspective of “people-oriented”,this study conducted quantitative analysis and systematic research on Green View Index,satisfaction and influencing factors of Green View Index in urban street space.Meanwhile,combining with the actual function and development potential of street space of Tai’an historic urban area.,the improvement target and design strategy are put forward and typical street space are selected to enhance the design.The main conclusions are as follows:（1）Through the analysis of the characteristics of the population and the satisfaction scores of Green View Index,it is found that there is a significant positive correlation between the value of street space Green View Index and the satisfaction scores of citizens,which means the street space with higher Green View Index in the historical urban area is more likely to be liked by citizens.The degree of satisfaction of GVI in Tai’an historic urban area is divided into five grade: ≤8%,8%-15%,15%-30%,30%-40%,>40%,which corresponding to citizens’ satisfaction with green vision rate as very poor,poor,average,good,excellent.（2）The average Green View Index of street space in Tai’an historic urban area is 24.31%,which overall score is "average".Overall greening shows the distribution characteristics of "high in the north and low in the south,high outside and low inside".There is a single variety of plants in the street,the gap between the construction level of each street greening is large and the trend of polarization is obvious.The mean value of Green View Index of the four types of street space is landscape street > traffic street > historical street > life leisure street.（3）Through the correlation and general regularity analysis of the influence factors of Green View Index,it can be concluded that in terms of street environmental factors,there is a high positive correlation between Green View Index and street space openness and moderate positive correlation between Green View Index and street walkability;in terms of plant impact factors,taking sycamore and other broad-leaved trees as the shade tree has the greatest influence on the improvement of green visibility in street space.As for the streets,fine configuration of trees,shrubs and herbs can significantly improve the Green View Index.Although there is a significant positive correlation between Green View Index and plant configuration,street tree DBH,crown width,number,however,a single change of a factor can not strongly affect the change of street space Green View Index,which means multiple factors should be allocated synthetically.（4）Through the potential analysis of low Green View Index and low satisfaction street space,Green View Index improvement goals,principles and targeted improvement strategies are proposed:（1）Policy guidance,scientific greening;（2）Checking leaks,filling the vacancy,dismantling the fence to expose plants;（3）Three-dimensional greening to enrich perspective;（4）Adjusting measures to local conditions and adding characteristic greening;（5）Careful maintenance and standardized management;（6）Multiple participation,building and sharing together.Finally,four typical street spaces are selected according to current situation of different streets to carry out Green View Index enhancement design practice.