The construction of an ecological security pattern (ESP) is one of the basic methods to protect regional ecological security and enhance people’s well-being. In the case of Anhui province, located in the Yangtze River Delta region of China, regional ecological sources were assessed and recognized in terms of ecosystem services, and regional ESP was then constructed based on circuit theory. Current density was applied to analyze the significance of patches and corridors and recognize sticking points, and thereby strategies were introduced to optimize regional ESP. Results of ecosystem services function assessment showed that there were 47 ecological patches, 107 ecological corridors, 16 pinch points, and six sticking points in the ESP of Anhui province. The watershed of the Yangtze and Huai rivers divides the ESP of the northern and southern Anhui, which has huge landscape spatial heterogeneity. Areas with relatively good ecological resources were basically located between Dabie Mountain area in the west and the low hilly area in the south of Anhui, with mostly woodland and farmland as ecological sources. However, cities in the northern Anhui, also in the north of the watershed of the Yangtze and Huai rivers, face severe situations in terms of environmental protection. This study conducted spatial analyses on ESP with different thresholds and proposed to classify different ESPs according to ecological control. This helps to alleviate the contradiction between economic development and environmental protection, and improve the supply capacity of regional ecosystem services, in order to satisfy the regional demand for ecosystem services. Meanwhile, this study offers more methods to construct regional ESP and introduces targeted measures to improve connectivity, which is of practical guidance for the connectivity and optimization of ecological patterns.

A well-functioning public bicycle system relates not only to its mode of operation, vehicle allocation, rental station layout and vehicle leasing configuration, but also the bicycle network structure and its formation. However, the latter aspects have been widely overlooked in China. Here, we help to further attract more researchers to conduct relevant studies and make suggestions for the development of public bicycle transport in many small and medium-sized cities across the world. We demonstrate how to explore the public bicycle network structure of a county-level Chinese city – Yixing – known for its clay ware and tourism. We show that complex network theory and shortest path analysis technology are useful in characterizing the public bicycle network structure, in aspects such as network topology, the spatial distribution of sub-networks and traffic flows. Finally, the paper proposes relevant urban planning strategies.

Public health emergencies are characterized by significant uncertainty and robust transmission, both of which will be exacerbated by population mobility, threatening urban security. Enhancing regional resilience in view of these risks is critical to the preservation of human lives and the stability of socio-economic development. Network resilience (NR) is widely accepted as a strategy for reducing the risk of vulnerability and maintaining regional sustainability. However, past assessments of it have not sufficiently focused on its spatial effect and have overlooked both its internal evolution characteristics and external threats which may affect its function and effectiveness. Therefore, we used the Yangtze River Delta Region (YRDR) as a case study and conceptualized an integrated framework to evaluate the spatial pattern and mechanisms of NR under the superposition of the COVID-19 pandemiv and major holidays. The results indicated that the topology of a population mobility network has a significant effect on its resilience. Accordingly, the network topology indexes differed from period to period, which resulted in a decrease of 17.7% in NR. For network structure, the Shanghai-Nanjing and Shanghai-Hangzhou development axes were dependent, and the network was redundant. In the scenario where 20% of the cities were disrupted, the NR was the largest. Furthermore, the failure of dominant nodes and the emergence of vulnerable nodes were key factors that undermined the network’s resilience. For network processes, NR has spatial effects when it is evolute and there is mutual inhibition between neighboring cities. The main factors driving changes in resilience were found to be GDP, urbanization rate, labor, and transportation infrastructure. Therefore, we propose a trans-scale collaborative spatial governance system covering “region-metropolitan-city” which can evaluate the uncertain disturbances caused by the network cascade effect and provide insights into the sustainable development of cities and regions.