Study On The Vitality Of Small Green Space In Old Urban Area Based On Multi-source Data

The rapid development of cities has led to the reduction of green space.With the increasing attention paid to the concept of health,more and more urban residents participate in green space activities.As the main activity space of urban residents,the vitality of small green space in the old urban area has become the focus of public attention.Taking the vitality of small green space as the research content,this paper selects 17 small green spaces in Qinhuai District of the old urban area of Nanjing as the research object,and carries out the following three aspects:(1)quantitative evaluation of green space vitality;(2)Explore the influence mechanism of environment on vitality;(3)Explore the significant environmental indicators and thresholds that affect the activities of the elderly;(4)Put forward the optimization strategy of green space vitality improvement and aging design.First,summarize the research on vitality and small green space;Second,determine the quantitative evaluation method of small green space vitality;Thirdly,according to the post evaluation system,literature review and interview,the environmental impact factors are selected,and the impact factors are clustered and graded;Fourth,through multi-source data collection means,obtain the basic data of crowd activities and environment of small green space in the old urban area of Nanjing;Fifth,evaluate the vitality degree,and use the linear regression method to explore the environmental indicators that have a significant impact on the vitality degree;Sixth,explore the environmental index threshold suitable for the activities of the elderly,and focus on the aging design strategy of small green space.Combined with the research,the following conclusions are obtained:(1)Significant environmental indicators affecting vitality.The environmental indicators that positively affect the vitality are the number of other green spaces in 500m circle(0.446)>pavilion area(0.421)>the length per unit area of sitting facilities(0.355)>green space shape index(0.231)>open square area(0.164)>number of lights(0.102);The index of negative influence on vitality is PM10 concentration(-0.275)>Pavilion height(-0.204)>Noise(-0.081)>toilet area(-0.077).(2)Environmental indicators affecting the activities of the elderly.The environmental indicators that have a significant impact on the elderly include the length per unit area of sitting facilities(1.330)>toilet area(-0.777)>fitness area(0.618)>green space shape index(0.266)>plant structure layers(-0.317).Compared with other groups,the elderly have more demand for fitness area,and pay more attention to the planting level of plants.(3)The threshold of environmental indicators suitable for the activities of the elderly.In the research scope of small green space of 300-10000 m~2,the length per unit area of sitting facilities arranged in the green space(the length per unit area of sitting facilities is the total length of facilities that meet the human body scale and can provide rest divided by the green space area)should be 0.069m/m~2;Secondly,it is suitable to set up fitness venues with an area of about 115 m~2for the elderly;The small green space with banded or irregular shape can attract the activities of the elderly,but it should not be narrow and long.The shape index is the best between 1.72-1.78;Finally,the elderly like to move in the space with simple plant community level and open line of sight.If considering the beauty needs the combination of trees and shrubs,the coverage ratio of trees and shrubs is 1.01,and the hedgerow of 60 centimeter is the best.Based on the above results,based on multi-source data,this paper quantitatively studies the vitality of small green space,evaluates the current situation of the vitality of small green space in the old urban area of Nanjing,and excavates the environmental factors that significantly affect the vitality and activities of the elderly,which provides an optimization strategy reference for the vitality reconstruction of small green space and the improvement of aging environment.