Hydrological reduction and control effect evaluation of sponge city construction based on one-way coupling model of SWMM-FVCOM: A case in university campus.

The exacerbation of global warming, the frequent incidence of extreme weather events, and the rapid urbanization have collectively contributed to the heightened prevalence of flooding in urban areas. As a result of this challenge, sponge city (SPC) has been adopted in China as an efficient means of preventing and controlling urban floods. To evaluate the hydrological reduction and control effect of sponge city construction (SPCC) within a university campus, a one-way coupled model integrating one-dimensional sewer hydrodynamic model (SWMM) and two-dimensional surface flow model (FVCOM), namely SWMM-FVCOM model, was established. The Nash-Sutcliffe efficiency (NSE) of the SWMM were greater than 0.75 under there rainfalls with different intensity, indicating the good reliability and stability of this model could be used in the subsequent simulation. An analysis of drainage capacity and the risk of urban flooding was conducted using this model before and after the implementation of SPCC, considering six rainfall scenarios. Implementing SPCC demonstrated an effective performance in mitigating surface runoff, regulating inspection well overflow, and reducing overflow volume in the study region. However, the efficacy of runoff control diminished proportionally with the escalation of rainfall return period. Simultaneously, the implementation of low impact development (LID) measures can significantly decrease the extent and magnitude of surface inundations. The reduction rate of SPCC on the area of waterlogging ranged from 55.84% to 72.50%. But the control rate decreased with increasing rainfall return periods, demonstrating that adopting SPCC can effectively mitigate the severity of urban flooding resulting from low rainfall return period events (Tr < 20 years). This study can provide scientific foundation for environment managers to evaluate the impact of urban flooding prevention and control on runoff pollution mitigation when adopting the implementation of SPCC.

Tan Y ，Cheng Q ，Lyu F ，Liu F ，Liu L ，Su Y ，Yuan S ，Xiao W ，Liu Z ，Chen Y ... -  《-》

The simulation, regulation capacity assessment and coping strategy of rainstorm runoff waterlogging in Zhu pai-chong Basin of Nanning, China.

Currently, China is experiencing a phase of rapid urbanization. With the frequent occurrence of extreme rainfall events within the context of climate change, the problem of heavy rainfall and waterlogging in many cities is very prominent. In November 2020, China issued a proposal for the construction of sponge cities across the entire region to significantly enhance the rainfall flood prevention and drainage capacity of cities and effectively improve the resilience of sponge city systems for flooding management. Therefore, this paper selected the Zhu pai-chong watershed in Nanning with frequent waterlogging disasters as an example. Based on underlying surface information, We used a coupled SWMM-LISFOOD model to simulate runoff and waterlogging processes and analyze the spatial and temporal evolution characteristics of the basin under 10 designed rainstorm return periods (0.25a-50a). The results confirm the substantial spatial and temporal variabilities of the runoff coefficient in the study area; impermeability was the main factor contributing to high runoff coefficient values. The spatial distribution characteristics of inundation area was general dispersion and local linear aggregation. Furthermore, this study assessed the effect of the control rate of blue‒green‒gray facilities on the actual storms, and the value ranged from only 48.6% (0.25a)-24.05% (50a). This study quantified the two-dimensional distribution of rainfall storage volume thresholds with or without considering the discharged from the pipe network. Quantitative mapping between the elements of "rainfall-storage volume of blue‒green‒gray facilities-runoff-drainage capacity of the pipe network-waterlogging level" was conducted within the study area as an example. Finally, an overall technical process scheme for rainfall and waterlogging management was proposed. The scheme covered the hydrological‒hydraulic mechanism, storage function of sponge facilities, engineering control response, nonengineering measures and intelligent management of rainfall and waterlogging during sponge city construction, which could provide critical scientific support for effective promotion of the construction of sponge cities in China.

Li Q ，Yang Y ，Liao H ，Liu M ，Liao L ，Huang S ，Sun G ，Mo C ，Li X ... -  《-》

Study on the response analysis of LID hydrological process to rainfall pattern based on framework for dynamic simulation of urban floods.

Liu C ，Xie T ，Yu Q ，Niu C ，Sun Y ，Xu Y ，Luo Q ，Hu C ... -  《-》

Effects of Low-Impact Development Facilities (Water Systems of the Park) on Stormwater Runoff in Shallow Mountainous Areas Based on Dual-Model (SWMM and MIKE21) Simulations.

Lai Y ，Lu Y ，Ding T ，Sun H ，Li X ，Ge X ... -  《-》

BK-SWMM flood simulation framework is being proposed for urban storm flood modeling based on uncertainty parameter crowdsourcing data from a single functional region.

In recent years, urban flood disasters caused by sudden heavy rains have become increasingly severe, posing a serious threat to urban public infrastructure and the life and property safety of residents. Rapid simulation and prediction of urban rain-flood events can provide timely decision-making reference for urban flood control and disaster reduction. The complex and arduous calibration process of urban rain-flood models has been identified as a major obstacle affecting the efficiency and accuracy of simulation and prediction. This study proposes a multi-scale urban rain-flood model rapid construction method framework, BK-SWMM, focusing on urban rain-flood model parameters and based on the basic architecture of Storm Water Management Model (SWMM). The framework comprises two main components: 1) constructing a SWMM uncertainty parameter sample crowdsourcing dataset and coupling Bayesian Information Criterion (BIC) and K-means clustering machine learning algorithm to discover clustering patterns of SWMM model uncertainty parameters in urban functional areas; 2) coupling BIC and K-means with SWMM model to form BK-SWMM flood simulation framework. The applicability of the proposed framework is validated by modeling three different spatial scales in the study regions based on observed rainfall-runoff data. The research findings indicate that the distribution pattern of uncertainty parameters, such as depression storage, surface Manning coefficient, infiltration rate, and attenuation coefficient. The distribution patterns of these seven parameters in urban functional zones indicate that the values are highest in the Industrial and Commercial Areas (ICA), followed by Residential Areas (RA), and lowest in Public Areas (PA). All three spatial scales' REQ, NSEQ, and RD2 indices were superior to the SWMM and less than 10%, greater than 0.80, and greater than 0.85, respectively. However, when the study area's geographical scale expands, the simulation's accuracy will decline. Further research is required on the scale dependency of urban storm flood models.

Liu C ，Li W ，Zhao C ，Xie T ，Jian S ，Wu Q ，Xu Y ，Hu C ... -  《-》