| The rapid urbanization brought by population growth and industrial agglomeration has led to shortage of land and urban space.A large number of ecological land has been occupied,which has a negative impact on the quality of urban ecological environment.With the agglomeration and accumulation of urban capital,labor force,industry and other factors,the living standard of urban residents has been improved,and simultaneously the contradiction between people’s growing demand for a better life and the ever-compressed green space has emerged.As a linear open space connecting parks,nature reserves,historical and cultural heritage and densely populated areas,urban greenway has become an effective means to improve the urban ecological environment and provide leisure,recreation and exercise space.It has been widely recognized and valued in the fields of ekistics,landscape scicence and environmentology.Since 2010,urban greenways in China have entered a rapid development stage.Many cities have promulgated greenway system construction plans.The scale of greenways has increased rapidly.Urban greenways have gradually become an important part of city life.At the same time,problems such as lack of management and low utilization rate have arisen in the management of urban greenways.The construction of greenways needs to change from purely pursuing quantity growth to a more rational stage of development that takes both quantity and quality into account.The vitality of public space is an important criterion for evaluating the attractiveness of public space and thus reflects the quality of public space.As a type of urban public space,urban greenway should play a role in stimulating the social interaction of urban residents and promoting the vitality of the city.Under the background that the quality of greenway space is gradually valued,greenway planning and design should pay more attention to building the vitality of greenway space.In order to implement the planning strategy of promoting the spatial vitality of greenway,it is necessary to clarify the factors affecting the spatial vitality of greenway,and then incorporate the factors affecting the spatial vitality of greenway into the process of greenway planning,so as to construct the urban greenway network with spatial vitality.Multi-source urban data provides an effective means to measure urban interior space and urban residents’ activities for urban greenway planning research,and promotes the research of urban greenway spatial vitality and urban greenway planning.Therefore,the purpose of this paper is to evaluate the use of greenways from the perspective of spatial vitality of greenways.With the help of multi-source urban data,the spatial and temporal characteristics and influencing factors of urban greenway spatial vitality are analyzed,and then the urban greenway planning method and optimization strategy based on spatial vitality are put forward.Specifically,the research contents of this paper include the following three aspects:(1)Spatial and temporal characteristics of greenway activities based on trajectory data.In order to overcome the shortcomings of the traditional methods,this paper uses the trajectory data to perceive the greenway activity at the city scale in a full period of time,and quantitatively analyses the temporal and spatial characteristics of the greenway spatial activity.Referring to the concept and measurement of public space vitality,the concept,elements and measurement methods of greenway space vitality are defined,which provides a new perspective for the evaluation of greenway space.The results show that:(1)The activities of greenways in Wuhan vary with the daily type and weather conditions.According to the statistical results of greenways,the activities of Donghu Greenway and Moshuihu Lake Greenway increase during holidays.At different times of the day,the greenway activity changes significantly.The activities of different greenways at different times of the day also have their own changing rules.(2)The activity intensity of each Greenway in Wuhan is quite different.The activity intensity of Donghu Greenway and Shahu Greenway is obviously higher than that of other greenways.Within each greenway,the activity intensity of different greenway segments also showed significant spatial differences.There are obvious differences in intensity distribution of greenway activities between working days and rest days.(3)The spatial vitality of greenway is composed of activity intensity and activity duration.The overall characteristics of the active duration of greenways in Wuhan are quite different from the spatial differentiation characteristics of activity intensity.Therefore,the greenway spatial vitality index can measure the spatial quality and utilization of greenway more comprehensively and effectively as it considers the active duration.Most greenways in Wuhan have a long active time,and the active time of Zhiyinhu Greenway is significantly lower than other greenways.On weekdays and rest days,the active duration of greenways in Wuhan has obvious type characteristics.Donghu Greenway and Jinyinhu Greenway are more leisure-type greenways carrying more leisure activities as they are active on rest days than on working days.The active duration of Zhinyinhu Greenway,Moshuihu Greenway and Shahu Greenway is longer in working days than in rest days.They are daily greenways that carry more daily activities of residents.(2)Analysis of environmental factors affecting the spatial vitality of greenway.Based on the environmental impact study of environmental behavior and public space vitality,the assumptions,conceptual framework and influencing factors of environmental impact analysis of greenway space vitality are put forward,and the environmental impact index system of greenway space vitality is established,and the influencing factors are quantified with multi-source urban big data.In each travel mode,the spatial vitality indexes of the whole greenway(activity intensity and active duration),daily greenway working day and leisure greenway rest day are respectively taken as dependent variables,and the factors of the greenway construction environment and greenway characteristics are taken as independent variables.A multi-mode and multi-dimensional regression model of greenway spatial vitality is established to analyze different outcomes.The relationship between the elements of greenway spatial vitality and the characteristics of built environment and greenway itself under different types of greenways and the influencing factors of greenway spatial vitality are summarized.The results show that:(1)There is a significant correlation between the spatial vitality of greenway and the characteristics of built environment and greenway itself.The fitting effect of local regression is better than that of global regression,and the regression coefficients of influencing factors are significantly different in spatial distribution.(2)The number of facilities,residents’ income,population density and number of service points are positively correlated with activity intensity in the three travel modes,and the correlation of residents’ income in the walking mode is the strongest.In the mode of motor vehicle travel,the spatial vitality of greenway is also related to the distance to bus stop,subway station and parking lot.(3)The regression results of GWR model show that there are obvious spatial differences in the impact of each index on the spatial vitality of greenway under different travel modes and different types of greenway.(3)Construction and optimization of greenway network based on spatial vitality.Based on the influencing factors of urban greenway spatial vitality,the greenway network construction model is improved,and the optimal greenway network is constructed by using suitability analysis and least cost model.The greenway planning method and optimization strategy based on greenway spatial vitality are proposed.The greenway network in Wuhan is mainly distributed in the central urban area.The new town group outside the central urban area lacks support and attraction for greenway construction due to the lack of ecological source,low population density and insufficient public service facilities.The distribution of the greenway network in the central urban area is similar to the distribution of population density and facility density.At the same time,the greenway mostly surrounds the water area to protect water body and provide recreational space.Based on the study of the factors affecting spatial vitality and the regional characteristics of the study area,this paper proposes that the following principles should be taken into account in the optimization of the greenway network in Wuhan: the principle of high residential density,the principle of high POI density,the principle of diverse landscape types and the principle of close to mountains and rivers.In this paper,the basic characteristics of greenway activities in Wuhan are analyzed with the help of bicycle movement data in Wuhan,and the application of motion trajectory data in large-scale and refined greenway evaluation is explored.Through the measurement of spatial and temporal characteristics of greenway spatial vitality in Wuhan,it is verified that the greenway spatial vitality index proposed in this study can more comprehensively and scientifically measure the use of greenway,reflect the quality of greenway space,and provide a new perspective for greenway evaluation.Through the analysis of the influencing factors of greenway spatial vitality,it is found that population density,the number of facilities and service points are the main influencing factors of greenway spatial vitality.At the same time,leisure activities and daily activities on greenway are affected by different factors.Through the construction of urban greenway planning model based on spatial vitality,the conclusion of this study and the practicability and universal applicability of GIS technology in greenway planning are proved,which provide scientific and effective methods and basis for improving the quality of urban greenway space. |
