Urban Pluvial Flooding Research Articles

A spatial accessibility assessment of urban tourist attractions emergency response in Shanghai

Tourism is particularly vulnerable to natural hazards. This paper presents a scenario-based study that assesses the spatial accessibility of urban tourist attractions' emergency response to urban pluvial flooding in Shanghai's city center, China, through the combination of flood hazard analysis and GIS-based network analysis. Emergency coverages and response times in various traffic conditions are quantified to assess tourist attractions' spatial accessibility using the water level conditions in the years of 2010, 2030, and 2050, normal flood-free, 100-year, and 1000-year flood scenarios. The findings indicate that the scope and depth of flooding, road traffic conditions, and the number and location of emergency medical service (EMS) jointly determine the scope and response time of urban flood hazard medical emergency services. Under flood scenarios, part of the road network is paralyzed, traffic is interrupted, and emergency vehicles cannot pass, resulting in a significantly smaller range of EMS space accessibility than usual. Under the 1000-year flood scenario, up to 22% of tourist attractions cannot obtain emergency services within 15 min. The method proposed in this paper can provide a decision-making basis for the emergency management of tourism under urban flood hazards.

Coastal and orographic effects on extreme precipitation revealed by weather radar observations

Abstract. The yearly exceedance probability of extreme precipitation of multiple durations is crucial for infrastructure design, risk management, and policymaking. Local extremes emerge from the interaction of weather systems with local terrain features such as coastlines and orography; however, multi-duration extremes do not follow exactly the patterns of cumulative precipitation and are still not well understood. High-resolution information from weather radars could help us quantify their patterns better, but traditional extreme value analyses based on radar records were found to be too inaccurate for quantifying the extreme intensities required for impact studies. Here, we propose a novel methodology for extreme precipitation frequency analysis based on relatively short weather radar records, and we use it to investigate the coastal and orographic effects on extreme precipitation of durations between 10 min and 24 h. Combining 11 years of radar data with 10 min rain gauge data in the southeastern Mediterranean, we obtain estimates of the once in 100 years precipitation intensities with ∼26 % standard error, which is lower than those obtained using traditional approaches on rain gauge data. We identify the following three distinct regimes which respond differently to coastal and orographic forcing: short durations (∼10 min), related to peak convective rain rates, hourly durations (∼1 h), related to the yield of individual convective cells, and long durations (∼6–24 h), related to the accumulation of multiple convective cells and to stratiform processes. At short and hourly durations, extreme return levels peak at the coastline, while at longer durations they peak corresponding to the orographic barriers. The distributions tail heaviness is rather uniform above the sea and rapidly changes in presence of orography, with opposing directions at short (decreasing tail heaviness, with a peak at hourly durations) and long (increasing) durations. These distinct effects suggest that short-scale hazards, such as urban pluvial floods, could be more of concern for the coastal regions, while longer-scale hazards, such as flash floods, could be more relevant in mountainous areas.

Stormwater Management Modeling in “Sponge City” Construction: Current State and Future Directions

In response to urban pluvial flooding and pollution, the Chinese government proposed a “sponge city” policy in 2013 that aims to improve urban stormwater management and promote sustainable urban development. However, at present, sponge city construction is still in its exploratory stage. It is still not clear which models are capable of simulating the six key processes (i.e., “retention,” “infiltration,” “storage,” “purification,” “discharge,” and “utilization”) of sponge city practices. Its various benefits (e.g., social, economic and environmental benefits) have not yet been systematically investigated in the context of the sponge city. In this study, we reviewed and compared 19 urban stormwater management models (including 13 hydrological models and 10 decision-support tools, as there are 4 overlap ones) and investigated their application in China. Firstly, we examined the mechanisms behind the hydrological models and compared the abilities of the models to simulate various processes. Secondly, we analyzed what kinds of benefits can be addressed by these decision support tools (DSTs). Finally, we discussed the applications and limitations of the models in various climate zones in China. The findings suggest that none of the models consider the impact of climate change on the sponge city practices (SCP) and none of DSTs can simulate the negative performance of SCP. Furthermore, the lack of sufficient databases in China limited the applications of many of the models. Additionally, we found that the hydrological processes corresponding to “storage” were given more attention in southern China, and “infiltration” of stormwater was of greater concern in northern China. In the context of sponge city construction, this paper provides suggestions for future model development of urban stormwater management in China, such as the development of a stormwater database and the incorporation of long-term climate change impacts into the model.

Public perception of the urban pluvial floods risk-case study of Porec (Croatia)

Pluvial floods are rain-related floods that occur when water drainage is not fast enough due to heavy rainfall. One of the key components in the management of the urban pluvial flood risk (UPFR) is risk perception (RP). The objective of this paper was to define factors of RP based on the selected variables and to examine their reliability. Emphasis is placed on the contextualization of five factors related to cognition: awareness of the risk of pluvial floods (F1) and situation: anthropogenic causes of pluvial floods (F2), natural causes of pluvial floods (F3), consequences of pluvial floods in the future (F4), and preparedness for pluvial floods (F5). Furthermore, historical pluvial floods data were acquired from multiple sources and used to determine the distance of respondents' homes from frequently flooded places. The results showed that the questionnaire was consistent, i.e., factors are highly reliable. Significant differences were observed in the F2 regarding the gender of the respondents, and in the F4 regarding their age. Preparedness for the danger (F5) is the lowest perceived factor. Results from this study can facilitate communication between experts, decision-makers, and citizens.

Increasing urban flood risk in China over recent 40 years induced by LUCC

Land use/cover change (LUCC) caused by urbanization has a great impact on urban hydrological systems, among which urban pluvial floods are particularly prominent and have attracted worldwide attention. Although some previous studies have shown that urban LUCC increases urban pluvial flood risk and reduces urban flood regulation service (UFRS) in individual cities, there has not been a nationwide quantitative assessment in China. Here, we use a data-driven hydrological model and constructed indicators to clarify the quantitative impact of LUCC on China's UFRS and its spatial pattern from 1977 to 2018. Our analysis revealed that LUCC has caused China's UFRS to decline by 13.39%, from 31.34% in 1977 to 17.95% in 2018. Spatially, the UFRS decline in all river basins in China was greater than 10%, and the UFRS in almost all cities was decreasing. Especially in the densely distributed eastern Yangtze River basin, Pearl River basin, Southeast basin, Haihe River basin and Huai River basin, their UFSR values decreased by 11.89%, 12.17%, 12.34% and 10.81%, respectively. This is a warning that China's urban land conversion has greatly increased the urban pluvial flood risk.

A city-scale fully controlled system for stormwater management: Consideration of flooding, non-point source pollution and sewer overflow pollution

An increase in severe urban pluvial flooding, non-point source (NPS) pollution and combined sewer overflow (CSO) pollution increasingly threaten human life and property. City-scale sustainable stormwater management has become alternative solutions. This research designed and evaluated a stormwater management system (sponge city) on city-scale. The differences between old and new districts, the coexistence of combined and separate drainage systems, pipeline defects and the corresponding groundwater/river infiltration were fully considered in the system design. Low impact development (LID) practices, drainage upgrading and terminal control approaches were integrated together. Sponge city implementation is a no-regrets adaption strategy that can offset the stormwater related pressures. Compared with baseline values, the maximum fraction of the conduit full depth decreased for the entire pipe network. Annual values of total inflow volume (TIV) and total flooded volume (TFV) decreased by 32.26% and 53.68%, respectively. Significant decreases in pollution release were also recorded, with reduction rates of 40.96% (chemical oxygen demand; COD), 71.18% (ammonia nitrogen; NH3-N), 41.57% (suspended solids; SS) and 50.40% (total phosphorus; TP). LID on its own allows the city as a whole to control runoff and to largely reduce NPS pollution; however, it has a limited ability to improve drainage capacity. Adopting grey approaches, such as drainage system rehabilitation and renovation, as well as storage tanks, was proved to be essential for drainage capacity improvement and pollution control on city-scale. However, final pollutant discharge depends on the relative amount of increased NPS loads and reduced CSO loads after implementing combined sewer separation projects. It is usually recommended to increase the NPS pollution control target when designing stormwater control system. Terminal facilities (such as riparian zones and storage tanks) are encouraged to better control NPS pollution. Methods and conclusions on the comprehensive consideration of urban complex conditions, systematic stormwater control and the effectiveness of different measures highlighted in this study on a city scale provide important reference for future urban sustainable stormwater management.

Propagation of radar rainfall uncertainties into urban pluvial flood modeling during the North American monsoon

ABSTRACT Pluvial flooding in urban regions is a natural hazard that has been rarely investigated. Here, we evaluate the utility of three radar (Stage IV, Multi-Radar Multi-Sensor or MRMS, and gauge-corrected MRMS or GCMRM) quantitative precipitation estimates (QPEs) and the Storm Water Management Model (SWMM) hydrologic–hydraulic model to simulate pluvial flooding during the North American monsoon in Phoenix. We focus on an urban catchment of 2.38 km2 and, for four storms, we simulate a set of flooding metrics using the original QPEs and an ensemble of 100 QPEs characterizing radar uncertainty through a statistical error model. We find that Stage IV QPEs are the most accurate, while MRMS QPEs are positively biased and their utility to simulate flooding increases with the gauge correction done for GCMRMS. For all radar products, simulated flood metrics have lower uncertainty than QPEs as a result of rainfall–runoff transformation. By relying on extensive precipitation and basin datasets, this work provides useful insights for urban flood predictions.

U-FLOOD – Topographic deep learning for predicting urban pluvial flood water depth

This study investigates how deep-learning can be configured to optimise the prediction of 2D maximum water depth maps in urban pluvial flood events. A neural network model is trained to exploit patterns in hyetographs as well as in topographical data, with the specific aim of enabling fast predictions of flood depths for observed rain events and spatial locations that have not been included in the training dataset. A neural network architecture that is widely used for image segmentation (U-NET) is adapted for this purpose. Key novelties are a systematic investigation of which spatial inputs should be provided to the deep learning model, which hyper-parametrization optimizes predictive performance, and a systematic evaluation of prediction performance for locations and rain events that were not considered in training. We find that a spatial input dataset of only 5 variables that describe local terrain shape and imperviousness is optimal to generate predictions of water depth. Neural network architectures with between 97,000 and 260,000,000 parameters are tested, and a model with 28,000,000 parameters is found optimal. U-FLOOD is demonstrated to yield similar predictive performance as existing screening approaches, even though the assessment is performed for natural rain events and in locations unknown to the network, and flood predictions are generated within seconds. Improvements can likely be obtained by ensuring a balanced representation of temporal and spatial rainfall patterns in the training dataset, further improved spatial input datasets, and by linking U-FLOOD to dynamic sewer system models.

Urban Pluvial Flood Management Part 2: Global Perceptions and Priorities in Urban Stormwater Adaptation Management and Policy Alternatives

Urban stormwater infrastructure is at an increased risk of being overwhelmed by pluvial flood events due to climate change. Currently, there are no global standards or frameworks for approaching urban rainfall adaptation policy. Such standards or frameworks would allow cities that have limited time, finances or research capacities to make more confident adaptation policy decisions based on a globally agreed theoretical basis. Additionally, while adaptation via blue-green infrastructure is often weighed against traditional grey infrastructure approaches, its choice must be considered within the context of additional policy alternatives involved in stormwater management. Using six global and developed cities, we explore to what extent a standardized hierarchy of urban rainfall adaptation techniques can be established through a combined Analytic Hierarchy Process (AHP) Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) Multi-Criteria Decision Analysis. While regional and stakeholder differences emerge, our study demonstrates that green infrastructure undertaken by public bodies are the top policy alternative across the cities and stakeholder groups, and that there exists some consensus on best management practice techniques for urban stormwater adaptation.

Urban Pluvial Flood Management Part 1: Implementing an AHP-TOPSIS Multi-Criteria Decision Analysis Method for Stakeholder Integration in Urban Climate and Stormwater Adaptation

Cities are facing increasing pressures to enact adaptation measures due to climate change. While blue-green infrastructure has emerged as a focal adaptation technique for stormwater management, in order to craft adaptation policies cities must consider a multitude of emerging, complex, and competing stakeholder interests around multiple adaptation alternatives. However, accounting for these different interests, analyzing their diverse priorities, and maintaining a transparent decision-making process is not easily achieved within the existing policy frameworks. Here we define and present a combined multi-criteria decision analysis (MCDA) of the analytic hierarchy process (AHP) and the technique for order of preference by similarity to ideal solution (TOPSIS) methods that easily integrates and quantifies stakeholder priorities while remaining accessible for non-experts engaged in the policy-making process. We demonstrate the method’s effectiveness through analyzing opinions about stormwater adaptation in New York City across several stakeholder groups. The method succeeds in integrating quantitative and qualitative judgements, indicating stakeholder preferential differences and allowing for more inclusive policy to be crafted. It can be extended beyond stormwater to many urban climate adaptation decisions facing multi-criteria considerations.

Urban pluvial flood adaptation: Results of a household survey across four German municipalities

AbstractIn recent years, German cities were heavily impacted by pluvial flooding and related damage is projected to increase due to climate change and urbanisation. It is important to ask how to improve urban pluvial flood risk management. To understand the current state of property level adaptation, a survey was conducted in four municipalities that had recently been impacted by pluvial flooding. A hybrid framework based on the Protection Motivation Theory (PMT) and the Protection Action Decision Model (PADM) was used to investigate drivers of adaptive behaviour through both descriptive and regression analyses. Descriptive statistics revealed that participants tended to instal more low‐ and medium‐cost measures than high‐cost measures. Regression analyses showed that coping appraisal increased protection motivation, but that the adaptive behaviour also depends on framing factors, particularly homeownership. We further found that, while threat appraisal solely affects protection motivation and responsibility appraisal affects solely maladaptive thinking, coping appraisal affects both. Our results indicate that PMT is a solid starting point to study adaptive behaviours in the context of pluvial flooding, but we need to go beyond that by, for instance, considering factors of the PADM, such as responsibility, ownership, or respondent age, to fully understand this complex decision‐making process.

The Relevance of Grated Inlets within Surface Drainage Systems in the Field of Urban Flood Resilience. A Review of Several Experimental and Numerical Simulation Approaches

Urban drainage networks should be designed and operated preferably under open channel flow conditions without flux return, backwater, or overflows. In the case of extreme storm events, urban pluvial flooding is generated by the excess of surface runoff that could not be conveyed by pressurized sewer pipes, due to its limited capacity or, many times, due to the poor efficiency of surface drainage systems to collect uncontrolled overland flow. Generally, the hydraulic design of sewer systems is addressed more for underground networks, neglecting the surface drainage system, although inadequate inlet spacings and locations can cause dangerous flooding with relevant socio-economic impacts and the interruption of critical services and urban activities. Several experimental and numerical studies carried out at the Technical University of Catalonia (UPC) and other research institutions demonstrated that the hydraulic efficiency of inlets can be very low under critical conditions (e.g., high circulating overland flow on steep areas). In these cases, the hydraulic efficiency of conventional grated inlets and continuous transverse elements can be around 10–20%. Their hydraulic capacity, expressed in terms of discharge coefficients, shows the same criticism with values quite far from those that are usually used in several project practice phases. The grate clogging phenomenon and more intense storm events produced by climate change could further reduce the inlets’ performance. In this context, in order to improve the flood urban resilience of our cities, the relevance of the hydraulic behavior of surface drainage systems is clear.

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

Urban pluvial flooding in China has become one of the major challenges for sustainable development. This paper analyzes the impact of climate change, urbanization, and integrated disaster drivers on urban pluvial flooding hazards, starting from the disaster-causing mechanisms of urban pluvial flooding in China. This paper then analyzes the main features and progress of urban pluvial flooding governance in China. In particular, this paper describes the progress of sponge cities in China. On the basis of the above contents, this paper describes three manifestations of the fragmentation dilemma at the level of governance, namely, fragmentation in value integration due to conflicting management orders and service values, fragmentation in resource and power allocation due to the lack of vertical top-level design and blurred horizontal departmental management boundaries, and fragmentation in policy formulation and implementation due to outdated urban flood control standards and interdepartmental information compartmentalization. In response to the fragmentation dilemma in urban pluvial flooding management in China, this paper introduces the concept of holistic governance and clarifies the path of urban waterlogging management, i.e., forming a collaborative and diversified governance subjects, deeply optimizing the organizational structure of urban waterlogging management, creating a mature information-based governance platform, and improving the legal and rule of law construction model. This paper is informative for understanding the governance of urban pluvial flooding in China from a government-led management level.

Assessing urban pluvial flood resilience based on a novel grid-based quantification method that considers human risk perceptions

The growing worldwide threat of urban flooding has stimulated research on flood resilience so that more targeted measures can be implemented in vulnerable areas to mitigate flood losses. During flood events, people generally show different risk perceptions for different inundation areas according to their population density, economic degree, and service function. In this study, the risk perception was quantified into weights and integrated into the resilience calculation to identify areas vulnerable to floods and posing a danger to human life and property. An area in Zhuhai, China, was selected as the research region. With the proposed novel method, the grid-based flood resilience under different rainfall scenarios and different time periods of the day (human work and rest hours) was researched. Moreover, the resilience of different land uses and the impacts of two critical parameters in the resilience equations were also studied. The results indicated that the risk perception related to a given land-use generally changed according to different periods of the day. The overall resilience of the research region was lower when more severe rainstorm occurred in a given time period. The resilience in the work hours was higher than that in the rest hours during the same rainstorm event, indicating that the living/working state of people affected the flood resilience in urban areas. Analyses of the two parameters provided plausibility verification for the parameters and indicated that a slight increase in the height of building doorsills substantially decreased the areas with low and very low resilience. And this decrease effect was more pronounced in the rest hours than the work hours. Results of this study provide an in-depth understanding of urban flood resilience and targeted guidance for engineering construction and flood management.

Analysis of pluvial flood damage costs in residential buildings – A case study in Malmö

Pluvial flood damage to residential buildings causes a significant part of direct tangible flood losses. In this study, we investigate the non-hazard variables and sewer system types in relation to damage costs in the city of Malmö, Sweden. A comprehensive data set of around 1000 records of direct damage to residential buildings from a cloudburst event on 31 August 2014 in Malmö, Sweden has been analysed at property scale with no lumping together of data. The results show that properties connected to combined sewer systems are much more exposed to pluvial flood damage than properties connected to separated sewer systems, with the ratio of the number of claims being close to three. The analysis of building-specific variables shows no clear statistical relationships to the damage costs. To further the understanding of damage costs caused by urban pluvial flooding, it is necessary to extend the group of explanatory variables to include information about the socio-economic background of households, the actual value of assets in basements and the precautionary measures taken by house owners.

China's ‘Sponge Cities’: The role of constructed wetlands in alleviating urban pluvial flooding

AbstractResearch examined constructed wetlands (CWs) in piloting the ‘Sponge City’, a Chinese initiative designed, in part, to curtail extensive urban pluvial flooding. In Yangzhou a small number of exploratory qualitative interviews with relevant professionals elucidated key issues. The interviewees supported the concept of CWs but were uniformly sceptical about their viability. A possible CW in the city was also modelled, quantifying its effects and limitations. Results show that CWs can help attenuate urban flooding but there are important caveats concerning their implementation. These concern their size and capacity, sufficiency of urban space, and their economic sustainability. The political dimension of the Sponge City concept, including support from President Xi Jinping, suggests that CWs may be a distraction from more widespread urban flooding, which CWs may well not alleviate. Piloting is continuing and results will need to be more positive if Sponge Cities can be a strategically important flood attenuation measure.

Assessment of Geologic Controls of Flooding in Parts of OBIO/AKPOR L.G.A., Rivers State, Nigeria

Flooding of Municipal areas is a frequent environmental occurrence in Rivers State that occurs when rainfall runoff meets land surfaces with low water absorbing capacity or when it overwhelms drainage channels. In order to assess the flood situation in the study area, an integrated method which involves Field-measurement, Geographic information system (GIS), Laboratory analysis of soil samples and topographic studies were employed. Digital Elevation Model of the study area reveals that the flooded areas are situated in areas with elevations lower than its surrounding, thereby acting as a natural basin to retain flood waters after rainfall. Four holes were drilled to depth of 3m to obtain soil samples at 1 m sampling interval, from which laboratory analysis was carried out to determine some geotechnical parameters such as soil’s particle size, specific gravity, bulk density, porosity, moisture content, permeability and hydraulic conductivity. Results from the analysis show that permeability, hydraulic conductivity and porosity diminishes with respect to depth. The soil in the flooded areas have high fines content (silt and clay), high bulk density which increase with depth and a specific gravity that is typical of organic rich soils that contain sand mixed with a considerable amount of fines. At Nkpolu, mean permeability rates of 0.003cm/sec, 0.009cm/sec and 0.033cm/sec were obtained at 1, 2 and 3m respectively. At Eneka, mean permeability rates of 0.011cm/sec, 0.018cm/sec and 0.014cm/sec were obtained at 1, 2 and 3m respectively, while at Rukpokwu, mean Permeability rates of 0.021cm/sec was obtained at 1m, while 0.006cm/sec was obtained at 2 and 3m respectively. The Mean hydraulic conductivity for the locations under study is of the order of 10-4ft/day. This study has shown that the flooded areas are located in low lying urban areas which act as basins, therefore, the top soil is crusted with highly compacted soil horizons beneath. With high and frequent rainfall in the region which generates a lot of runoff, in addition to poor drainage system, flooding of the study area occurs frequently. Therefore, construction and maintenance of efficient drainage channels for an effective solution to urban pluvial flooding in the study area are thereby recommended.

Developing a framework for attribution analysis of urban pluvial flooding to human-induced climate impacts

This study proposes a framework for the attribution analysis of urban flooding to historical anthropogenic climate impacts using real (historical) and counterfactual (natural) simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6) general circulation models (GCMs). A cluster analysis is implemented to select independent GCMs and to decrease the high computational time of the urban flood modeling. A two-step spatiotemporal statistical downscaling based on the generalized extreme value (GEV) distribution parameters is performed to meet the requirement of a fine-scale precipitation resolution for the urban flood simulations. Using the downscaled distribution parameters, the intensity–duration-frequency (IDF) curves and composite design storms for four return periods of 2, 10, 20 and 50 years are created to be used as the inputs of an InfoWorks ICM hydrodynamic model for a case study in Antwerp city, Belgium. The fraction of attributable risk (FAR) framework and the causal counterfactual probability theory are used to quantify anthropogenic climate influences on urban pluvial flooding. The results show that the GEV parameters of location and scale nicely follow the power relation, providing an opportunity for the temporal downscaling of precipitation extremes. A disagreement is found between the GCMs on the contribution of anthropogenic climate factors on pluvial flooding, some illustrating a higher probability of flooding due to anthropogenic climate impacts, and some a lower one. It can therefore be concluded that the urban flooding in Antwerp is not attributable to anthropogenic climate impacts.

Determination of Optimal Meshness of Sewer Network Based on a Cost—Benefit Analysis

Urban pluvial flooding occurs when the capacity of sewer networks is surcharged due to large amounts runoff produced during intense rain events. Rapid urbanization processes and changes in climate increase these events frequency. Effective and sustainable approaches for the reduction in urban floods are necessary. Although several gray, green and hybrid measures have been studied, the influence of network structure on flood occurrence has not yet been systematically evaluated. This study focuses on evaluating how different structures of a single urban drainage network affect flood volumes and their associated damages. Furthermore, a cost–benefit analysis is used to determine the best network structure. As a case study, a sewer subnetwork in Dresden, Germany was selected. Scenarios corresponding to different layouts are developed and evaluated using event-wise hydrodynamic simulation. The results indicate that more meshed structures are associated with lower flood volumes and damage. Moreover, all analyzed scenarios were identified as cost-effective, i.e., the benefits in terms of flood damage reduction outweighed the costs related to pipe installation, operation and maintenance. However, a predominantly branched structure was identified as the best scenario. The present approach may provide a new cost-effective solution that can be integrated into the development of different mitigation strategies for flood management.

Climate change impact assessment on pluvial flooding using a distribution-based bias correction of regional climate model simulations

The expected intensification of extreme precipitation events under climate change likely results in more frequent and intense pluvial floods worldwide. To study the climate change impact on urban pluvial flooding, fine-scale climate model simulations are needed. The number of such simulations is, however, still limited and not widely available, thus entailing the downscaling of the model outputs. One of the commonly used methods to meet this demand is statistical downscaling, where the statistical properties of large(r)‐scale climate simulations are used to derive local climate variables. This study focuses on applying a distribution-based bias correction method on regional climate model (RCM) simulations to explore how climate change affects extreme precipitation and urban flood events at the end of this century (2071–2100). A 1D-2D hydrodynamic model, implemented in Infoworks ICM, is used to simulate pluvial flood events for several return periods for a case study in the city of Antwerp in Belgium. The results show that the statistical downscaling approach can effectively decrease the bias in the model simulations and offer strong scaling relations to derive high-resolution extreme precipitation time series. The analyses also reveal that climate change may cause an increase of 16%, 31%, 47%, 63%, 73% and 84% in the flood volume for 2-, 5-, 10-, 20-, 30- and 50-year return periods, respectively. This projected increase in the flood volume enlarges the inundated area by 32%, 49%, 56%, 58%, 58% and 59% for the respective return periods. The flood frequency is also projected to almost double in the future, so that a 5-year flood event in the historical period will most likely be a 2-year event in the future period.