The global urbanization process is currently taking diverse territorial forms, leading to increased consumption of rural space through the creation of eco-cities. Within this context of transformation and the shifting nature of urban spaces, concepts and ideological frameworks are emerging to address environmental degradation caused by population concentration. Ecological Civilization (eco-civ) originated in China as a broad framework for managing new territorial processes through the construction of new eco-cities or the development of a comprehensive rural revitalization program that strengthens the urban-rural relationship. The major questions arising from this new process of rural revitalization in Chinese territories—and from the very concept of ecological civilization—can be summarized as follows: a simplification of the countryside, a loss of rural identity, the emergence of a post-agrarian society, the urbanization of rural areas, and an exacerbation of urban dependence on rural areas. Consequently, alternative approaches are proposed, based on multiple place-based approaches and actions that develop and adapt the fundamental principles of environmental and spatial renewal to each specific territory.
In order to reveal the spatio-temporal evolution of extreme rainstorm events in China and the changing characteristics of population exposure in different periods, this study systematically explored the spatio-temporal evolution characteristics of four indicators of extreme rainstorm frequency, duration, peak and cumulative amount, as well as the difference of population exposure to extreme rainstorm events in 2000 and 2020, based on the relevant data of extreme rainstorm and population distribution grid data from 2000 to 2020, using spatial analysis and trend analysis methods. The results show that in space, the frequency, peak value, and cumulative amount of extreme rainstorms are increasing from northwest to southeast, the southeast coast is a high value area, and there is almost no extreme rainstorm in the northwest arid area; The high-value areas of duration are concentrated in the Qinghai Tibet Plateau and Northeast China. In terms of time, from 2000 to 2020, the frequency of extreme rainstorm in Northeast China increased, the southern part of the Qinghai Tibet Plateau and other regions decreased, the peak value of rainstorm in North China Plain and the eastern coast increased, Taiwan Province showed a significant downward trend, and the change rate of rainstorm accumulation was stronger in the south and weaker in the north. In terms of spatial concentration, the high value concentration area of extreme rainstorms generally shifts to South China, while the low value concentration area is stably distributed in the northwest and part of the north. In terms of population exposure, the distribution characteristics of 2000 and 2020 are low in the northwest and high in the southeast, and the exposure of capital cities in southeast coastal provinces to extreme rainstorm frequency and peak in 2020 is significantly higher than that in 2000. Population migration and the evolution of extreme rainstorm events are the main driving factors. This study clarifies the temporal and spatial evolution law of extreme rainstorm events in China and the characteristics of population exposure change, which provides a scientific basis for regional extreme rainstorm disaster risk assessment, disaster prevention and mitigation planning, and optimization of population and urban development layout, and has important practical significance for improving the ability to respond to extreme climate events and ensuring regional population security and sustainable development.
This study aims to promote residential rainwater harvesting everywhere rain falls. It recalls the history of urban rainwater (stormwater) management while insisting on the origin of the perception that rainwater is not a relevant source of potable water. It also argues that where rainwater is polluted, it can be easily treated using frugal technologies such as filtration on metallic iron-based filters. The study notes that stormwater is precipitation that is not harvested. Thus, harvesting rainwater prevents (quantitative) stormwater generation, and transforms stormwater from a threat (e.g., erosion, floods) to a resource (e.g., drinking water, food security) for human and environmental needs. The effective management of stormwater (i) enhances the quality of human life, (ii) sustains local biodiversity, and (iii) protects the whole environment. Thus, the failure to harvest rainwater should be considered irresponsible, if not unethical. This argument alone makes each conscientious citizen a changemaker. A number of local changemakers will organize to determine the best way to integrate overflow from individual residences to enhance the community’s liveability. This study provides a valuable consolidation of information that will facilitate the mainstreaming of rainwater harvesting as the pillar of holistic integrated water resource management.
To address the endurance limitations of traditional electrically driven underwater gliders, which are constrained by onboard battery energy density, harnessing marine renewable energy for propulsion or supplemental power has emerged as a critical approach to overcoming their operational endurance bottleneck. This paper systematically reviews the research progress on underwater gliders powered by environmental energy sources, such as thermal and solar. It provides an in-depth analysis of the utilization mechanisms, core technologies, and current challenges associated with each energy type, with a focused exploration of technical pathways for achieving energy synergy and enhancing system endurance through multi-energy integration and intelligent energy management. Furthermore, this study is the first to establish a comprehensive technical evaluation framework for environmentally powered gliders from three dimensions: energy coupling, system design, and mission adaptability, offering a systematic reference for subsequent research. The paper also explores the application potential of this technology in advanced scenarios, such as long-term ocean observation and dynamic environmental monitoring. Future efforts should prioritize efficient multi-energy hybridization, dynamic energy management, and mission-adaptive control to comprehensively enhance the endurance and operational reliability of gliders in complex marine environments.
