Predicting the minimum scale of urban ecological space based on socio-ecological systems analysis.

Determining the minimum scale of ecological space that is sufficient for sustainable urban development is one of the difficult tasks in quantitative urban ecological research. In this study, we first expounded on the basic concept of the minimum scale of urban ecological space and reviewed the research status. Supported by the theory of "aggregation and dispersion" in landscape ecology, we converted the task of scale prediction into spatial accounting-oriented scenario simulation. We then proposed a method to predict the scale, based on an analysis of socio-ecological systems, and constructed a research framework of "construction constraint analysis - ecological importance evaluation scale prediction." The rules to discriminate the optimal scenario and the characteristics indices of the network were also proposed. Second, we selected Shenzhen City as a representative study object and constructed 87 ecological networks under different scenarios, based on the construction constraints and spatial distribution of ecosystem services, identified from the multi-source data in the study area. By calculating and comparing the network efficiency and clustering coefficient, we concluded that the network under the m39 scenario has the optimal connection efficiency and structural stability. We finally obtained a threshold of 48.85 % as the minimum proportion of ecological land in Shenzhen. We expect that this result can help improve the rationality of decision-making in urban spatial planning and governance.

An integrated cognitive framework for understanding modern cities.

Modern urban development urgently requires a new management concept and operational mechanism to encourage the exploration of frameworks for cognizing and studying urban characteristics. In the present study, modern cities are first understood from the perspective of their basic theoretical evolution. Each modern city is seen as a complex system of organic life forms. Urban information science propels modern urban research in the direction of rationality. This paper also presents the new characteristics of modern cities (and how they have changed) in relation to external structure and internal functions. It examines the generation of urban problems and governance adaptability. On this basis, this paper proposes a cognitive model for studying modern cities, integrating basic theoretical, methodological support, and governance systems. It discusses the basic rationale and core idea for constructing each of these three systems. The research aims to guide and implement modern urban construction and sustainable development in a more effective way.

A diagrammatic method for the identification and resolution of urban spatial conflicts.

Spatial conflicts are formed in the process of urbanization and become the primary drivers of urban ecological and environmental problems. The defining trait of a spatial conflict is the occupation of ecological or agricultural spaces by construction spaces. This work presents a classification scheme for spatial conflicts in China, including source-area conflicts, corridor conflicts, safety conflicts, and farmland conflicts. Also, it constructs a model for the determination of spatial conflicts and conflict intensity using diagrammatic method. Based on a case study performed using our methods on Shenzhen, we proposed a timeline and policy roadmap for the resolution of spatial conflicts in Shenzhen according to the severity and characteristics of spatial conflicts in the city. The results show that the total spatially conflicted area of Shenzhen is 10.57 km2, and the percentage of construction land-use in these areas is 1.37%. The spatial conflicts are mainly source-area or corridor conflicts, and minor conflicts account for approximately 60% of the total conflicted area. Most of the spatial conflicts are either "easy to resolve" or "moderately easy to resolve". Overall, in terms of the severity of spatial conflict, Shenzhen remains at the "stable and under control" level. Considering the primary aim of spatial conflict resolution is to revert built-up lands into urban green spaces, we proposed a timeline for the resolution of spatial conflicts in Shenzhen over the next 15 years, as well as a system of supporting policies. The results of this study shall serve as a guide for the optimization of urban spatial structures and the promotion of sustainable urban development.

Ecological control line: A decade of exploration and an innovative path of ecological land management for megacities in China.

Ecological control line is a system innovation in the field of ecological environment protection in China and it has become as an important strategy of national ecological protection. Ten years have passed since the first ecological control line in Shenzhen was delimited in 2005. This study examines the connotations of ecological control line and the current study status in China and abroad, and then takes a brief description about the delimitation background and existing problems of the ecological control line in Shenzhen. The problem-solving strategy is gradually transforming from extensive management to refined management. This study proposes a differential ecological space management model that merges the space system, management system, and support system. The implementation paths include the following five aspects: delimiting ecological bottom lines to protect core ecological resources; formulating access systems for new construction projects to strictly control new construction; implementing construction land inventory reclamation assisted by market means; regulating boundary adjusting procedures and processes; and constructing ecological equity products by using multiple means to implement rights relief. Finally, this study illustrates the progress of the implementation and discusses the rigorousness and flexibility problems of ecological control line and calls for the promotion of the legislation. The management model and implementation paths proposed in this study have referential significance for developing countries and megacities to achieve ecological protection and sustainable development.

Toward a sustainable utilization of land resources in China: problems, policies, and practices.

China's economy is growing explosively with double-digit rates of growth. However, behind the scenes of this economic miracle, a dark underbelly exists. The potential impact of the unsustainable use of land resources is increasing. Each parcel of land has a stationary geographic location, while its utilization is optional. The re-adjustment and optimization of land use patterns ought to be encouraged. Spatial reconstruction refers to the combination of various land elements, which can promote the rational and efficient allocation of land resources through a four-layer action framework: the development of unused land, urban renewal, ecological reconstruction, and spatial displacement. The feasibility and validity of these methods are illustrated by practical cases in different provinces in China. We thus propose that pursuing sustainable development and building an ecological civilization will be necessary for China in future decades.