Shuai Tong

With the acceleration of climate change and the increase of extreme rainfall, the risk of flooding has intensified in the Huang-Huai region, which is often hit by floods. Urban water accumulation is a complicated process, and the hydrological simulation analysis is highly accurate, but it is time-consuming and laborious. Machine learning is becoming an important new method because of its ability to analyze large areas with high precision. In this paper, a simulation analysis method based on machine learning is constructed by selecting 13 disaster factors, and the waterlogging point in Xuzhou city is predicted successfully. The following conclusions are found: (1) Among the five machine learning models, CatBoost has the highest accuracy rate, reaching 81.67%. (2) Temperature, elevation, and rainfall are relatively important influencing factors of waterlogging. (3) Machine learning can discover water accumulation areas that are easily overlooked except for the built-up areas. (4) The results of the coupling analysis show that the exposure risk of the population exposed to rainwater in the old urban area, the southern area, and the northwestern area is relatively high. This research is of great significance for reducing the risk of exposure to rain and flooding and promoting the safety and sustainable development of cities.

Between 2019 and 2022, passenger volume on China’s urban rail transit system sharply declined due to strict COVID-19 control measures. On 8 January 2023, China implemented the “Class B infectious disease Class B management” policy, marking a significant shift towards a more relaxed approach to epidemic control. The main objective of this study is to evaluate the immediate and lasting effects of this policy on urban rail transit passenger volume. We used interrupted time series (ITS), combined with quasi-Poisson regression models and counterfactual analysis, to analyze monthly urban rail transit operation data covering the period from January 2021 to June 2024 for 42 cities. Our analysis shows that, relative to the expected trend without any intervention, monthly average passenger volume increased by approximately 101.34% after the policy’s implementation, with significant immediate effects observed in 41 cities and significant lasting effects observed in 33 cities. The study concludes that the “Class B infectious disease Class B management” policy has generally promoted the nationwide recovery of urban rail transit passenger volume, although with significant heterogeneity across cities. This result indicates that the reduction in travel restrictions and the restoration of public safety, resulting from the relaxation of COVID-19 prevention and control measures, contributed to the overall recovery of urban rail transit. This study not only provides innovative methodological insights but also offers valuable guidance on developing more effective urban planning strategies and urban rail transit operational measures in the post-pandemic era.

As an important measure for maintaining the ecological environment, green infrastructure also plays a significant role in industrial development and economic growth. The current traditional green infrastructure construction method is based on a combination of vertical and horizontal ecological processes, but it does not take into account the complexity of the ecosystem or the motivating effect of green infrastructure on industry. This study investigated how green infrastructure can play the leading role in industry while considering the complexity of the ecosystem. Hanwang Town is the most representative village and town in China with the leading agricultural tour-industry, and it is located in the northern part of Jiangsu Province. However, the ecological security patterns of villages and towns have been severely damaged in recent years, and the green infrastructure has not played a role in industry. Therefore, taking Hanwang Town as the research area, the data of the third national survey were combined with relevant statistical data. Then, from the perspective of the agriculture and tourism industries, ecosystem services were used as a bridge to improve the recent green infrastructure construction methods, and finally better strategies are proposed according to the optimization results. The research results revealed three important aspects of this system. (1) The optimization method can comprehensively consider the impact of environmental factors, objectively reflect the value of ecological services in the form of currency, reflect the importance of environmental protection with intuitive values，and enhance people's awareness of ecological protection. (2) The selection of ecological factors takes into account the local characteristic industries of Hanwang villages and towns, and adding the appropriate industry-related ecological factors makes the identification of ecological sources based on ecosystem services more scientific, and can also bring benefits to the local residents. (3) The newly constructed green infrastructure fully takes into account the landscape, ecology, tourism and other roles played by tourist attractions on the ecological corridor. There are six tourist attractions in the selected ecological nodes, forming an ecological network space with an agglomeration economic function, and this allows the ecological service function to better integrated. The findings of this research can effectively solve the shortcomings of the traditional green infrastructure construction methods, and reveal optimization strategies for the problems existing in the current green infrastructure construction in Hanwang Town. At the same time, they can also provide a reference for the green infrastructure construction of agricultural and eco-tourism villages and towns in other regions.

Resource-exhausted cities usually face problems of environmental degradation, landscape fragmentation, and impeded ecological mobility. By clarifying the spatial heterogeneity of ecological restoration needs, efficient and coordinated ecological protection and restoration can be carried out. This study selected Jiawang District, a typical resource-exhausted city, and constructed an ecological security evaluation framework to determine the ecological source area from the three aspects of ecosystem service importance, ecological sensitivity, and landscape stability. The resistance surface was corrected with ecological sensitivity evaluation data, and ecological corridors and ecological nodes were identified using circuit theory. Finally, it explored the spatial and temporal evolution of the key areas of territorial ecological restoration in Jiawang District. This study indicates that: (1) In 2000, 2010, and 2020, the ecological source areas were 123.59 km², 116.18 km², and 125.25 km², and the corresponding numbers of ecological corridors were 53, 51, and 49. The total lengths of the ecological corridors were 129.25 km, 118.57 km, and 112.25 km, mainly distributed in the northern and central areas of the study area. (2) The study area contained 17, 13, and 19 ecological pinch points in 2000, 2010, and 2020, respectively, 16, 20, and 15 ecological obstacle points, and 8, 24, and 33 ecological fracture points, respectively. Targeted rehabilitation of these key areas can significantly improve ecological connectivity. (3) The key area of territorial ecological restoration in 2020 was composed of 125.25 km² ecological source area, 8.77 km² of ecological pinch point, 12.70 km² of ecological obstacle point, and 33 ecological fracture points. According to the present situation of land use, protection strategies are put forward.

The protection and utilization of ecological environment are very important for urban and rural development. At present, a large number of relevant theoretical and practical explorations have been carried out, which confirms the important conclusion that lucid waters and lush mountains are invaluable assets. The sustainable development of ecological environments is based on coordination with human production and life. In this paper, by constructing an accounting system for the gross ecosystem product (GEP) applicable to Hanwang town, using the market value method, the alternative cost method, the travel cost method, the willingness to pay method and other technical methods, the GEP of Hanwang town is calculated from three aspects: product supply, regulation service and cultural tourism. Finally, the spatial distribution characteristics of value are used to guide the development and layout of ecological industry in Hanwang town. The results showed that the total ecosystem product value of Hanwang town in Xuzhou was relatively high, reaching 1.165 billion CNY, with per capita reaching 30 million CNY, which was 49.16% of the town’s GDP in 2020. The value of cultural tourism is 820 million CNY, the value of regulatory services is 239 million CNY, and the value of product provision is 106 million CNY. The ecological value of Hanwang town varies greatly in spatial distribution. On the whole, the price is low in the southwest, but high in the northeast. The high-value areas are mainly concentrated in three areas: Yudai River Riverside, Xuzhou Paradise in the north, Hanwang Scenic Spot in the middle and the Panaxi Valley tourist spot in the south. Based on the principle of ecological value transformation, combining with the spatial distribution characteristics of ecological value in Hanwang town, four modes of promoting ecological value transformation were proposed: ecological industrialization management, ecological governance and value promotion, ecological resource index trading and ecotourism. This paper preliminarily explores a method to calculate and transform the value of ecological space, which provides feasible concrete strategies for the protection of ecological space and the development of ecological industry in towns.

The over-exploitation and utilization of natural resources in mining cities has caused sharp contradictions between urban development and ecological protection. In addition, dynamic changes in resources and environmental carrying capacity (RECC) will be changed by the different ways and degrees of the specific utilization of natural resources. In order to better study the dynamic trends and reasons of the RECC in mining cities, so as to provide methods and suggestions for the mining cities to save resources, improve the ecology, and adjust the industrial structure, this article will construct an evaluation index for the RECC of mining cities. Taking Huaihai Economic Zone as the research object, we used the entropy method to determine the index weight. Then, the TOPSIS model was used to analyze the spatial and temporal characteristics of the development of the RECC of mining cities in coal-concentrated areas during 2012–2018. After the analysis, the study found five results. (1) Except Zaozhuang, the RECC of the six mining cities in the Huaihai Economic Zone showed a steady upward trend during 2012–2018; (2) among the three subsystems, natural resources have the greatest impact on the RECC; (3) in terms of space, the carrying capacity in this region gradually has a polarization phenomenon centered on Xuzhou and Jining, and will continue to increase in the future; (4) the types of mining cities will have an impact on the change characteristics of the RECC; and (5) most cities improve the level of ecological carrying capacity (ECC) and social economic carrying capacity (SECC) at the cost of the decline of resources carrying capacity (RCC). Based on the results, the research can provide optimized reference strategies for the transformation and development of mining cities to ecological cities in Huaihai Economic Zone.

The transfer space realizes the connectivity of subway intersections. Passengers generally express that they have a poor experience in the use of this space, so improving the environmental suitability of transfer spaces at subway stations is a top priority. Based on a literature review and field research, this study established an environmental suitability evaluation system for transfer spaces and used the fuzzy comprehensive evaluation method to evaluate the environmental suitability of eight samples in Shanghai. The results showed that the evaluation results of the eight samples were ranked as follows: Hanzhong Road Station > People’s Square Station > East Nanjing Road Station > Century Avenue Station > Xujiahui Station > Laoximen Station > Jiangsu Road Station > Shanghai Railway Station. Through the analysis of the relationship between the indicators, it was found that the environmental suitability of a transfer space is greatly affected by safety and convenience, while practicality, comfort, and aesthetics were found to have a weak influence on the suitability of transfer spaces. These evaluation methods and results provide a reference for the improvement of the environmental quality of subway transfer spaces in other cities.

The construction of green infrastructure (GI) plays an important role in improving the rural ecological functions and building a green livable environment. In this paper, the methods of morpho spatial pattern analysis (MSPA) and space syntax analysis are used to study the GI network construction in Suining County, Jiangsu Province. The results show that: (1) In 2018, the area of ecological patches increased by 110% compared with 1998, and the utilization rate of the GI network was significantly improved. (2) A total of 66 ecological corridors were analyzed in the county, and the main corridors were distributed in the central and western regions. The correlation analysis of core ecological patches in 1998, 2008, and 2018 proved that location factors had the greatest impact on the results of function and connectivity. (3) According to the optimization results, ecological benefits can be improved through engineering measures to realize the revitalization and development of regional rural areas.