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As the global climate change and the rapid progress of urbanization, the frequent occurrence of flooding disasters and non-point source pollution seriously threaten the sustainable development of modern cities. To alleviate these problems, China started to pilot construction of the "Sponge City" (SPC). Over a decade, it has attracted public attention, supports, and participations. The paper presents a literature review of sponge city construction (SPCC) process (planning, design and construction) as well as the assessment of SPC, including: operation, maintenance, and effectiveness. Research gap and future works are also proposed. The paper offers some tactics for SPCC, including: 1) in the planning and construction stage of SPC, the goals and systematic plans should be formulated according to local water-environmental conditions. The drainage plan should cover the strategy to dispose runoff volumes at sources and the ultimately goal for flood mitigation. The drainage design involves the combination of various green and grey infrastructures; 2) It is important to identify monitoring methods and hydrological models which can be used to assess the performance of a SPC. With adequate field data, all models and methods should be calibrated for not only runoff quantity and quality control but also the alleviation of urban heat island effects, including the base flows and local groundwater table; 3) Based on the regional field data, it is necessary to standardize regional design parameters, construction material specifics, and maintenance scheme and schedule that would significantly affect the facility's infiltrating and filtering processes, therefore, a regular maintenance program should be initiated to monitor the operations of the as-built facilities according to local climate conditions. The paper evaluated several maintenance methods for ten typical facilities to provide a reference for the operation and maintenance of facilities in SPCC. • The sponge city construction (SPCC) and design methods were introduced in detail. • Scientific and reasonable assessment can better guide the SPCCs. • The sponge city (SPC) facilities can be a better way to control stormwater runoff. • Monitoring and simulation method are equally important for assessing SPC effect. • A maintenance program should be initiated to monitor the operations of SPC facility. [ABSTRACT FROM AUTHOR]

Since the beginning of 2020, the weak domestic power demand caused by the COVID-19 pandemic and the large-scale advancement of coal power construction projects may have further aggravated the coal power overcapacity in China. Given the new situation, this study collected the data on China's installed electricity capacity and electricity demand during the 13th Five-Year Plan period. Moreover, a reasonable capacity evaluation model of coal power was established based on the energy and electric power balance to analyze China's coal power overcapacity in 2019 and determine the reasonable capacity for 2025. The internal reasons of unreasonable energy structure and regional difference of energy structure are systematically discussed. Results show that the overcapacity in 2019 was approximately 170 GW, and the overcapacity situation in North, Northwest, and South China was particularly serious. The reasonable coal power capacity for 2025 under the basic situation is 950 GW, indicating that if all the coal power units under construction and planning are operated, the overcapacity in 2025 will be 300 GW. Sensitivity and comprehensive scenario analyses show that under different scenarios, the upper and lower limits of the reasonable coal power capacity in 2025 are 1083 and 794 GW, respectively. Finally, this paper proposes relevant policy recommendations to cope with China's serious coal power overcapacity problem. [Display omitted] • Capacity evaluation model of coal power is established. • Quantitative analysis is provided for each regional power grid of China. • The coal power overcapacity of China exceeds 170 GW in 2019. • The overcapacity situation may further deteriorate during the 14th FYP period. • A reasonable scale of coal power is 950–1000 GW at 2025. [ABSTRACT FROM AUTHOR]