Comprehensive Understanding the Disaster-Causing Mechanism, Governance Dilemma and Targeted Countermeasures of Urban Pluvial Flooding in China

Historical and comparative overview of sponge campus construction and future challenges

Frequent urban flooding has caused great economic losses and casualties worldwide. Sponge cities have attracted attention as an important means of flood control and disaster reduction. This paper systematically and comprehensively analyzes the development of sponge campuses in China and other countries and compares classic examples of sponge campus construction. We identify the following issues in sponge campus construction: lack of appropriate numerical simulation model, low public engagement and support of sponge campuses, and a lack of standardized guidance for sponge campus construction. Based on the in-depth analysis of successful examples of sponge campus construction in developed countries, and combined with consideration of China's economic development, geographical location, and urbanization level, we suggest the future development direction of sponge campus: the development of local sponge campus models; popularization of sponge theory; improvement to public participation and experience; improve the financial system of sponge campus; and standardization of guidance for sponge campus construction and maintenance. This paper expounds on the necessity of sponge campus construction and further improves the theoretical system of sponge campuses. These results can provide theoretical support and reference for the construction or transformation of sponge campuses in colleges and universities and then promote further development of sponge campuses.

Analysing the Performance of Four Hydrological Models in a Chinese Arid and Semi-Arid Catchment

Frequent flood hazards in the Raoyang River Basin in western Liaoning, China, have posed serious threats to people’s lives and property. In an effort to study the simulation efficiencies of hydrological models in this arid and semi-arid catchment, this study examined the performance of the Xin’anjiang model, the Liaoning unsaturated model, and the DHF model in the Dongbaichengzi station watershed in the upper reaches of the Raoyang River, China. Additionally, this paper proposed an improved DHF model, which considers the impoundment and regulation of small- and medium-sized reservoirs in the upper reaches of the basin. The flood simulation results demonstrated that the Xin’anjiang model was difficult to apply in this area because the average value of its Nash–Sutcliffe efficiency (NSE) was as low as 0.31. Meanwhile, the simulation efficiencies of the Liaoning unsaturated model and the DHF model were higher than that of the Xin’anjiang model, but the relative error of flood peak discharge and runoff depth for most floods were still high and could not meet the actual forecast requirements by the Reservoir Administration Bureau of Liaoning Province. Overall, the improved DHF model showed the best efficiency, and the mean value of the NSE reached 0.79. Therefore, the improved DHF model has good applicability in the Dongbaichengzi station watershed in the upper reaches of the Raoyang River, China.