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In response to the COVID-19 pandemic, many U.S. citizens sought information and support from their city governance through the 311 non-emergency service request system. The main purpose of this study was to analyze the temporal trends in the 311 data before and during the first few months of the COVID-19 pandemic (3/1/2019 to 9/1/2020). Like other major U.S. cities such as Dallas and New York City, analysis of Kansas City 311 data showed that the COVID-19 pandemic has led to a considerable decline in the aggregate number of calls. However, five service categories (“Public Safety”, “Public Health”, “Trash/Recycling”, “Parks & Recreation”, and “Property/Buildings/Construction”) experienced a substantial increase in call volume. To explore whether these changes are driven by COVID-related service requests, we used the description text data and identified 2,379 requests related to the pandemic, accounting for 4.3% of all non-emergency requests in Kansas City between March and August 2020. More than half of the COVID-related requests reported mask violations, where people failed to wear masks or did not wear masks properly. Compared to the non-COVID-related requests, citizens were more likely to seek non-emergency services through phone and email and less likely to use the web as means of communication. In addition, most changes in “Public Safety” and “Public Health” request volumes were driven by these COVID-related requests. These results can help city officials and decision makers improve the city’s resilience by allocating resources for the abovementioned five service categories during a pandemic. In conclusion, early-stage analysis of open-access 311 data can be a catalyst for local governments to quickly and properly respond and build long-term resilience against future pandemics and other health threats. LESS      Full article

Social institutions such as hospitals and schools are among the main pillars of community stability. A drop in the functionality of hospitals and schools is likely to have short-term and long-term effects on a community, including a reduction in medical interventions, an increase in unschooled children, and population outmigration in search of essential social services. However, comprehensive community resilience models that consider the role played by social institutions in community stability following natural disasters are scarce at the present time. This paper provides a literature review and critical appraisal of previous studies on the resilience of hospital and school systems and their impact on community well-being. The review encompasses existing resilience models for single hospitals and schools, their role when connected with other hospitals and schools in a network, their reliance on each other as interdependent systems, and their role in community resilience and stability. Different mitigation strategies and policies to enhance hospital and school systems’ resilience after extreme natural hazards are also summarized. The paper concludes with a series of recommendations to improve current models for social institutions, enhance the connection between existing hospital and school resilience models and community resilience frameworks, and develop social stability indices that policymakers can use in preparing and mitigating future extreme events. LESS      Full article

Modern cities are prone to various natural and human-made hazards. To deal with these challenges, an effective risk analysis, reduction and management tool is required for all relevant threats. In recent years, a risk analysis and safety management system called the Multi-Hazards Shanghai (MH-SH) system was developed by the Shanghai Institute of Disaster Prevention and Relief to serve the policy makers of government in Shanghai for various disaster decision making of prevention and mitigation. The system can handle various disasters including earthquake, flood, typhoon and man-made fire that affect the operational security of Shanghai. In the paper, the general frame of the MH-SH system was briefly presented. Advanced methodologies and technologies were discussed for their capability of enhancing the platform in multi-disaster monitoring, detection, prediction and management. Finally, the way to the future development of the MH-SH system was concluded. LESS      Full article

Ensuring the safety of large curved-roof structures subjected to blizzards in cold regions remains challenging. This paper assesses the reliability of a large curved-roof structure considering the coupled effects of wind and snow. To this end, a two-way coupled simulation considering the interaction between snow particles and turbulent wind is first carried out using a computational fluid dynamics scheme and a spectral representation method based on the wavenumber-frequency joint power spectrum and stochastic harmonic function; thereby, the uneven snow distribution and stochastic wind field on a large curved roof are revealed. The probability density evolution method is then adopted to conduct a stochastic response and reliability analysis of the structure. The simulation results reveal that a credible uneven distribution of snow on the large curved roof can be obtained using the suggested snowdrift simulation scheme, and the refined spectral representation method can efficiently and accurately simulate the two-dimensional fluctuating wind field of the large curved-roof structure. It is shown that under stochastic wind, snow and self-weight loads for a 100-year return period, the large curved-roof structure has a higher risk of member yielding than of node deflection. Meanwhile, the axial stress acting on the structural member is far less than the maximum allowable stress and the structure is thus deemed to be sufficiently safe. LESS      Full article

The failure of urban street trees caused by strong winds and has several adverse effects on urban functions and public safety. This study developed a wind fragility model based on the mechanical analysis of urban street trees. The uncertainty of the important parameters involved in this model was quantified for species of interest. Specifically, the vine copula function was used to estimate the joint probability distribution of the geometric parameters. Furthermore, the tree fragility curves were obtained and then validated by the historical measured date. The proposed model may help in effectively identifying high-risk streets and regions. LESS      Full article

One major threat to cities at present is the increasing rainstorm waterlogging hazards due to climate change and accelerated urbanization. This paper explores the mechanism of rainstorm waterlogging and enables the fine simulation of surface water propagation over complex urban terrain. A novel community-scale waterlogging modeling scheme is presented by loosely coupling a one-dimensional sewer model with a two-dimensional overland model under an open-source framework. The coupled model was applied to Waigaoqiao Free Trade Zone located in Pudong New Area of Shanghai. To quantify the influence of rainfall intensity and drainage conditions on the waterlogging, 12 scenarios were constructed by combining four rainfall return periods (3, 5, 10, and 20 a) and three startup water depths (1.5, 2.0, and 2.5 m) of pump stations. The multi-scenario simulation results show that the waterlogging risk increases from north to south in the study area, and that risk zones with water depth above 0.3 m are mostly concentrated in the southwest and southeast corners of the site. The longer the rainfall return period, the larger the submerged area, and the spatial distribution of surface water accumulation is affected by local topography and drainage system. In addition, reducing the startup water depth of pump stations has an obvious effect on inhibiting the severity of water accumulation. The results provide insights into overland flow across an urban area with densely populated buildings and help to reduce the risk of rainstorm-induced waterlogging disasters. LESS      Full article