Search Results (161)

Urban pluvial flood risk in industrial zones is intensifying under climate change, yet the joint influence of digital elevation model (DEM) resolution, surface roughness heterogeneity, and infiltration capacity on simulation accuracy remains insufficiently characterized. This study presents a comprehensive sensitivity analysis combining five DEM resolutions (0.5, 1, 2, 5, and 10 m), six rainfall scenarios (10- to 200-year return periods plus the observed event of 10 July 2024), and three infiltration rates (5, 10, and 20 mm h⁻¹), yielding 90 simulation cases executed with the open-source GPU solver SynxFlow on an NVIDIA A100 80GB GPU. A spatially distributed Manning’s roughness field (n_M = 0.013–0.100 s m^−1/3) was derived from the Ministry of Environment land cover product, replacing the conventional uniform-roughness assumption. Model performance was assessed against seven validation gauges (five flooded, two no-flood controls) compiled from contemporaneous news reports, using the 25 m × 25 m patch-maximum simulated depth at each gauge and probability of detection (POD), false alarm ratio (FAR), and critical success index (CSI). The 0.5 m baseline achieved POD = 0.80, FAR = 0.20, and CSI = 0.67 at the 5 cm depth threshold. Coarsening the grid reduced peak depth by up to 37% and flooded area by 5%, with the most rapid degradation occurring between 2 m and 5 m. A 2 m grid retained area error within 2% and volume error within 1% while delivering an approximately 33-fold runtime reduction relative to the 0.5 m baseline; the 10 m grid achieved up to ~1400× speedup, spanning three orders of magnitude across the resolution range. Resolution sensitivity intensified under higher rainfall and lower infiltration, confirming that “adequate” resolution is conditional on event severity. A tiered resolution selection matrix linking application scale, target accuracy, and computational cost is proposed to support evidence-based flood adaptation planning for industrial zones. Full article

With increasingly frequent extreme rainfall and high-density urban development, urban pluvial flooding has become a major challenge to public safety in coastal built-up areas. Existing studies have mainly focused on hydrological and engineering factors such as rainfall, drainage, and topography, while paying limited attention to the heterogeneity of the micro-scale built environment around flood-risk sites and its statistical associations with residents’ average psychological responses. Taking 78 flood-risk buffers in the inland built-up area of Zhuhai as the study area, this study develops an integrated framework combining street-view semantic segmentation, topographic indicator extraction, entropy weighting, cluster analysis, questionnaire surveys, and multiple linear regression. Based on 2351 street-view sampling points, 9404 street-view images, and 9508 valid questionnaires, eight environmental indicators were extracted and aggregated to the buffer level to examine their statistical associations with average perceived emotional stress and negative anxiety. The results identify five typical micro-risk scenarios and show that water exposure, barrier proxy, and building enclosure are the most discriminative variables. Regression analysis further indicates that buffers with higher water exposure, barrier proxy, and building enclosure tend to report higher average perceived emotional stress and negative anxiety, whereas buffers with higher green view index tend to report lower average psychological burden. These findings suggest that urban pluvial flooding is not only a hydrological-engineering issue, but also a compound urban risk that is visualized, spatialized, and contextualized at the street-view scale. This study contributes by shifting flood research from flood-generating factors to buffer-level risk scenarios and physical–psychological association patterns, offering a replicable framework for integrating street-view, GIS, and social perception data. Full article

This study introduces a modelling framework for representing surface runoff along urban streets during intense rainfall events. The approach incorporates a dynamic assessment of sewer system capacity, obtained through dedicated simulations that capture its temporal variability during flooding. A one-dimensional sewer model is first used to quantify the volume of rainfall effectively conveyed by the drainage network; these results are then used to construct a reduced hyetograph, which serves as input for a one-dimensional street-flow model. The methodology was applied to a flood-prone urban catchment in southern Italy and calibrated and validated using field observations, including direct measurements and video-derived flow estimates. Full article

Urbanization and climate change are increasing pluvial flooding risks, thereby intensifying the need for more adaptive stormwater governance in Chinese Sponge City projects. Although public participation is widely recognized as important, current research frequently conceptualizes it as a simplified or static attribute and seldom provides explicit criteria for identifying representative projects in large urban portfolios. This study develops a life cycle-sensitive framework for evaluating public participation in Sponge City projects by conducting a cross-city comparison in China. The study integrates project inventory construction, evidence-based representative project selection, and a multidimensional participation measurement tool covering breadth, depth, identity, and potential across planning, design, construction, and maintenance using five national pilot cities: Jinan, Shanghai, Xiamen, Shenzhen, and Wuhan. The results show that the five representative projects display distinct life cycle participation profiles, rather than a single participation pattern, influenced by project type and governance arrangement. Maintenance emerges as the strongest documented stage, whereas design is the weakest, suggesting stronger documented governance continuity after project delivery than in front-end co-design. Recurrent weaknesses remain in substantive inclusion and feedback-adoption closure. Overall, the study frames participation as a structured governance capability, providing an auditable comparative framework for identifying participation strengths and weaknesses in Sponge City governance. Full article

This study presents a practical application of a subgrid approach for urban pluvial flooding that implicitly accounts for the secondary drainage network. Parameters required by the subgrid model (e.g., pipe diameter, spacing) can be easily estimated, reducing the data requirements and modelling efforts compared to classical 1D/2D simulations. Applied to simulate the 2009 flooding of a Padova district, the model improves accuracy in flood extent and water levels compared to models that ignore the secondary network, without the need for surveys of smaller-scale pipes. This data-efficient approach proves to be a practical tool for simulating urban pluvial floods, particularly in data-scarce urban areas. Full article

One of the consequences of urbanization is the impermeabilization of the landscape, which increases the stormwater runoff and the risk of pluvial flooding. To address this challenge, this study proposes a methodology to quantify the impact of reducing impermeable areas in the design of pluvial drainage systems. This methodology is applied in the Lake Ganzirri Area, located in Messina, Italy, where accelerated expansion of residential projects and the closure of drainage outlets due to environmental restrictions have enhanced the risk of pluvial flooding. The relationship between impermeable areas and the impact on risk of failure is assessed using rainfall events derived from regional depth-duration-frequency curves, a pluvial drainage network, and InfoWorks ICM simulations for different impermeable scenarios. Full article

Natural hazards and their negative impacts on assets are increasing because of a variety of causes, including climate change, population expansion, and urbanization. Moreover, several areas are susceptible to multiple hazards that interact spatially and/or temporally, necessitating a multi-hazard assessment to adequately mitigate their effects. The goal of this study is to investigate the direct monetary losses produced by the simultaneous interaction of two independent hazards in Lisbon’s city centre, i.e., earthquake and pluvial flood. Seismic hazard has been assessed in terms of macro-seismic intensity, while flood scenario allows for the prediction of water depth for different return periods through a hydrologic-hydraulic model in HEC-RAS software. The seismic and flood vulnerability of the urban investigated compound was evaluated through MCDM methodology—specifically, AHP and TOPSIS methods. A framework for multi-hazard analysis was subsequently developed, explicitly accounting for the interaction between the two hazards and their joint occurrence probabilities based on historical data from the case study area. The results demonstrate that multi-hazard losses are 108 M€ for a 2-year return period and 232 M€ for a 475/500-year scenario, emphasizing that floods contribute more across all return periods in the research area; however, for longer return periods, the earthquake contribution increases significantly. Full article

Climate-driven intensification of pluvial and fluvial flooding increasingly challenges lowland cities in Central Europe, while conventional protection and land-use controls offer limited flexibility under growing hydrological variability. A planning-oriented framework is developed and tested to integrate hydro-adaptive housing into climate-resilient urban development using three typologies: elevated foundations, amphibious dwellings and modular floating platforms. The framework links hazard profiles and site-enabling conditions to typology selection and considers supporting blue–green measures within the broader adaptation context. It is applied to three flood-prone settings in northern Poland representing a coastal delta, a river confluence and a lower-river terrace. The methodology combines GIS-based hazard mapping; one-dimensional unsteady-flow HEC-RAS simulations for 50-, 100- and 500-year design events; and parametric structural modelling in Rhino–Grasshopper. Performance is assessed using maximum inundation depth, surface-water retention time, and a probabilistic building damage index. Amphibious dwellings reduce modelled 100-year flood damage by 62% relative to slab-on-grade construction, while modular floating platforms maintain habitability under water-level rises exceeding 5.0 m. In addition, bioretention and blue–green corridors reduce retention time by 18–31%. The results provide a planning-oriented decision logic for expanding adaptive housing options in flood-prone lowland settings under increasing hydrological variability. Full article

Best Management Practices (BMPs) are key instruments for improving the resilience of urban environments to climate change and land-use pressures. They mitigate pluvial flooding and heat waves by restoring natural soil processes and providing multiple co-benefits at both the building and urban scale. Urban planning increasingly requires comprehensive assessments of the multiple benefits provided by BMPs, which extend beyond their hydrological function. Traditional hydrological models such as SWMM5 are robust and widely used for simulating drainage performance, but they are not designed to evaluate wider co-benefits or to be easily applied in planning contexts. For this reason, simplified tools have been developed to offer quicker and more accessible assessments, although their reliability, especially in reproducing hydrological outcomes, remains uncertain. This study examines the Green Values Stormwater Management Calculator (GVC), which has been developed to combine hydrological and co-benefit evaluations within a single, easy-to-use framework. In this preliminary analysis, we tested the hydrological module of the GVC on a 290-hectare mixed-land-use catchment in the metropolitan area of Milan, where two calibrated SWMM5 drainage models were available as benchmarks: one representing current conditions and another including a retrofitting design with BMPs. The scenarios were simulated with the GVC and compared under selected storm events in terms of total runoff volumes. The results show that the GVC reproduces current-condition runoff with good accuracy, but tends to underestimate BMP efficiency. Full article

Urban pluvial flooding poses increasing challenges due to climate change and rapid urbanization. The limited availability of information on subsurface drainage infrastructure and of validation data frequently constrain large-scale flood modelling. This study applies a pragmatic modelling framework, using a two-dimensional hydrodynamic model (HEC-RAS 6.7) within the Rain-on-Grid approach to simulate rainfall-induced flooding in Naples, Italy. The adopted method simplifies subsurface drainage processes while enabling a scalable application across large urban areas. The results identify flood-prone areas within the city and provide insights into pluvial flood modelling in data-scarce urban contexts. Preliminary validation is performed using flood photographs and videos collected from social media. Full article

Pluvial floods can cause severe socio-economic impacts on coastal urban areas like the Metropolitan Area of Barcelona. This study combined the development of high-resolution flood maps, based on a large-scale coupled 1D/2D model and empirical functions, to quantify direct economic damage to buildings and determine risk to pedestrians and vehicles. Importantly, the flood model included a network of 36 municipalities and covered 636 km². Three scenarios were considered: single-hazard (extreme precipitation), multi-hazard (coincident extreme precipitation and storm surge), and adaptation (implementation of resilience measures). In total, 20 rain events were applied for each scenario: 5 were historic design storms, while 15 considered the effect of climate change (60 simulations in total). By the end of the century, results show potential increases in expected annual damage of up to 36%, from €139.8 M to €190.3 M. Risk for pedestrians could increase by 25% (494 ha to 620 ha) and for vehicles by 26% (59 km to 75 km) in the T10 single-hazard scenario. In the multi-hazard case, the socio-economic impacts are approximately 5% higher, while the adaptation simulations considering sustainable urban drainage systems show reductions between 6 and 18%. The metropolitan results were compared and validated with a previous assessment done in the City of Barcelona. Based on these results, urban planners, emergency responders, and public administrations can develop effective adaptation measures based on cost–benefit analyses for current and future climate scenarios. Compared to previous studies, this approach adapts existing urban-scale methodologies to regional-scale flood risk assessment. Full article

Mountainous megacities face a distinctive form of pluvial waterlogging in which terrain-controlled flow convergence, accelerating imperviousness, and aging drainage interact to produce chronic, spatially clustered failures rather than stochastic events. Existing frameworks, such as hydrodynamic modeling, data-driven machine learning, and multi-criteria composite indexing, carry distinctive failure modes at the municipal scale. This study develops and externally validates a city-wide, grid-based assessment framework for Chongqing, China, through three integrated choices. First, resilience is reformulated as a stabilized adaptation-to-risk ratio and subjected to an explicit falsification test against independent waterlogging observations. Second, multi-source hydroclimatic, topographic–hydrologic, land-cover, and service-accessibility indicators are integrated on a 500 m fishnet (22,500 cells) through within-component CRITIC–Entropy weighting and TOPSIS, with robustness diagnosed by a 500-iteration Monte Carlo weight-perturbation analysis. Third, a spatially grouped LightGBM classifier with SHAP interpretation serves both as an independent validation layer and as a mechanistic lens on non-linear driver thresholds. The composite risk surface achieves ROC-AUC values of 0.834 and 0.873 against two independent waterlogging registries, is strongly spatially clustered (Moran’s I = 0.81, p < 0.001), and preserves its ranking under aggressive weight perturbation (Spearman ρ ≥ 0.95 in 95% of scenarios). A counterintuitive finding emerges from the falsification test as resilience yields ROC-AUC below 0.5 on both point sets, indicating that accessibility-based capacity proxies systematically capture urban centrality rather than drainage robustness, like a diagnosable measurement problem affecting the wider resilience-index literature. LightGBM concentrates 88.0% of waterlogging cells within the top 10% of scored grids, and SHAP-derived thresholds align with saturation-ponding, well-drained, and convergence–hotspot regimes of classical hydrology. Together, these results reframe waterlogging assessment in complex terrain from a cartographic exercise into a falsifiable, resource-aware prioritization framework, and clarify why capacity maps and risk maps should be published as complementary instruments of flood governance. Full article

Urbanization increases pluvial flood risk by expanding impermeable surfaces, which is a trend likely to intensify with climate change. Permeable pavement (PePav) made from industrial byproducts, in accordance with circular economy principles, may improve soil permeability. Public acceptance remains a critical barrier to its implementation. Existing measures of willingness to accept (WtA) new technologies are inconsistent, limiting interdisciplinary collaboration. Therefore, a concise WtA scale was adapted from the Bogardus Social Distance Scale to assess acceptance of PePav at varying levels of proximity in residential contexts, from public flood-prone roads to private yards. The scale was evaluated across three studies: Study 1 (N = 195) and Study 2 (N = 187) utilized mixed student samples, while Study 3 (N = 625) involved a non-student sample. The 5-item solution, identified through factor analysis in Study 1, consistently demonstrated a unidimensional and cumulative structure and satisfactory reliability, even after the proposed PePav ingredient modification in subsequent studies. The scale correlated with recycling experience and professional background, indicating convergent validity, but not with flooding or informal construction experience, across all samples. Study 3 provided evidence of external validity by incorporating empirically well-established Theory of Planned Behavior (TPB) constructs and showing that WtA predicted PePav use beyond TPB variables and demographics. The scale also showed measurement invariance across sample type (student vs. general population) and different levels of construction experience. The constructed WtA scale is suitable for efficiently assessing professional and public acceptance of circular building materials and may have broad cross-disciplinary relevance. This enables timely, targeted interventions and informed policy decisions to advance sustainable technologies in the built environment, with substantial implications for education, professional policy, and sustainable engineering. Nevertheless, further validation is required. Full article

Urban pluvial flooding is becoming more severe in rapidly urbanizing cities under increasingly frequent extreme rainfall. Although Low Impact Development (LID) is widely used to improve infiltration and on-site stormwater retention, its hydrological performance may differ greatly across urban functional zones with distinct land-cover patterns, development intensity, and retrofit constraints. To address the lack of comparative evidence under consistent conditions, this study mapped land cover in five representative functional zones in Nanjing—old residential, new residential, commercial, industrial, and cultural/educational areas—and applied a unified CITYgreen (SCS-CN) framework under a 72 mm, 24 h, two-year design storm to simulate four standalone LID measures: ground-level greening, permeable pavement, green roofs, and grassed swales. Results showed big zone-dependent differences in hydrological benefits. Runoff reduction was greatest in highly impervious industrial and commercial areas, whereas the new residential zone showed only a marginal improvement due to its relatively favorable baseline retention conditions. Across all zones, measures that enhanced infiltration and near-surface storage performed best, with ground-level greening and permeable pavement achieving the highest retention efficiency. These findings highlight the importance of zoning-based, context-sensitive LID prioritization for urban renewal, sponge-city retrofitting, and stormwater planning in rapidly urbanizing cities. Full article

This paper explores the behavioural change process initiated within the Gdańsk Coastal City Living Lab (CCLL)—a site-based effort, initiated under the H2020 SCORE project and significantly deepened through the Horizon Europe PRO-CLIMATE project—through the lens of transforming human–nature relationships for sustainable urban biodiversity conservation. While SCORE established the technical baseline for Nature-based Solutions (NbSs), PRO-CLIMATE provides the critical behavioural framework to ensure these solutions are socially adopted and sustained. Located in a flood-prone coastal city, the Gdańsk CCLL addresses the critical need for nature-based solutions (NbSs) in minimizing the negative impacts of climate change, particularly pluvial flooding. At the heart of this initiative is a participatory change process facilitated by local Change Agents in collaboration with key stakeholders across water management, local government, academia, and civil society. Drawing on interdisciplinary insights from social science, the paper uses the Nature Futures Framework to analyse how conservation actions are influenced by the relational, intrinsic, and instrumental values that stakeholders and residents attach to nature. The paper situates these values in the Gdańsk context and examines how they shape motivations and willingness to engage in urban NbS, such as green roofs, retention parks, and rainwater gardens. The study presents qualitative findings from stakeholder engagement workshops, Change Agents’ reflections, and support mechanisms from behavioural change experts. It evaluates how behavioural change was facilitated through shared vision building, feedback loops, and trust-based relationships, and how barriers were negotiated. A key contribution of the paper is the exploration of how bottom-up and top-down processes intersect in urban adaptation strategies and how behavioural change frameworks can be designed to institutionalise sustainable human–nature interactions in urban governance. The Gdańsk case offers transferable insights for other cities facing climate vulnerabilities while striving to embed biodiversity conservation into everyday practice. Full article