An Urban Open Space Extraction Method: Combining Spectral and Geometric Characteristics

This paper introduces an advanced method based on remote sensing and Geographic Information System for urban open space extraction combining spectral and geometric characteristics. From both semantic and remote sensing perspectives, a hybrid hierarchy structure and class organization of open space are issues and mapped from one to another. Based on per-pixel and segmentation mechanism separately, two classification approaches are performed. Owing to prior of spatial aggregation and spectral contribution, the segmentation-based classification exhibits its superiority over a pixel-based classification. Finally a GIS-based post procedure is hired to eliminate some unsuitable open space components in both spatial and numerical constraints on the one hand, and separate open space some fabrics from fused remote sensing classes by defining their Shape Index on the other hand. The case study of Beer Sheva based on ASTER data proves this method is a feasible way for open space extraction.

Evaluation and Promotion of the Service Capacity of Urban Public Open Spaces Based on Improving Accessibility:A Case Study of Shenyang City,China

The service capacity of urban public open spaces is an important indicator of the justness and soundness of the allocation of public space resources,such as parks and green spaces,in the process of urban development.Improving the service capacity of urban public open spaces is conductive to healthy,sustainable urban development.In this study,taking Shengyang City,China as a case study,a Gaussian-based two-step floating catchment area method(2 SFCA)is used to calculate an accessibility index and identify residential areas with a poor accessibility to urban public open spaces.Then,a particle swarm algorithm(PSA)is used to optimize the locations of new open space developments.Finally,the optimization results are verified using the analytic network process(ANP).The results show that the service capacity of public open spaces in the center of Shenyang City(covering six districts)is relatively low and exhibits an uneven spatial distribution.In the service scope of the existing urban public open spaces,the accessibility for 48.6%of the residential estates is moderately poor or poor.The layout is optimized when the number of optimization points is set to 8.These points are mainly located in old town areas such as the Tiexi,Huanggu,and Dadong districts.The optimization increases the green space area accessible by motor vehicles(60 min),bicycles(60 min),and walking(30 min)by 4.67%,5.38%,and 8.03%of the study area,respectively.Finally,green space planning recommendations are offered from two perspectives:spatial layout and transport system optimization.

Human Behavior in Downtown Public Spaces during Cooling Periods in Winter Cities

There is an urban design problem that outdoor public spaces are not used for long periods of time within a year due to coldness and snow cover in cities with severe winter climates （winter cities）. Therefore, an urban design that promotes activities in these spaces is required for winter cities. The purpose of this paper is to clarify the relationship between outdoor environmental conditions and the behaviors of people in outdoor public spaces. This six-month study conducted a field survey in six kinds of public spaces in downtown Sapporo and analyzed the changes of microclimates and sitting behaviors in these spaces. The analysis revealed that sitting behaviors decreased with temperature drops during the cooling period （20 ~C-8 ~C）, that sunlight could suppress the reduction in the number of sitting behaviors, and that wind speed could suppress the reduction in the duration of sitting behaviors.

The Importance of Legibility and Its Relationship with the West End Regeneration Programme

Legibility is a significant quality of urban spaces. It affects people's knowledge of space and options available to them. This paper focused on the importance of the legibility of urban spaces and its relationship with urban design projects, and took the regeneration of Oxford's West End for example to il ustrate how to make urban open green spaces clearly legible.

Governance of Urban Green Open Space for Responding to Climate Change

In the global actions to address climate change, urban open green space is one of the main spatial objects that can be used to effectively mitigate greenhouse gases and to promote the implementation of climate adaptive policies. From a global perspective, this paper firstly analyzes the governance strategies and cooperation mechanisms of urban open green space as responding to climate change in European countries. Then, taking the Central City of Beijing as a case, the paper explores its urban thermal environment, distribution of urban open green space, and climate governance operation based on the specific conditions in China. Further, with the digital technologies of GIS and RS, it analyzes the nature and related governance demands of urban open green space and then divides the Central City of Beijing into four governance zones, following which this paper discusses the climate policy strategies and implementation approaches of each governance zone.