City Flood Research Articles

Characterizing urban morphology types for surface runoff estimation in the Oforikrom Municipality of Ghana

The frequency and severity of floods in Ghanaian cities have been increasing. Typically, increased floods have been attributed to climate change with limited evidence. Although this may be true in some cases, it minimizes the role of landscape change as a result of urban growth. Given the complexity of cities, this study characterizes urban morphology types and incorporate them with physiographic data to estimate the peak surface runoff in the Oforikrom Municipality of Ghana. The urban morphology was categorized into high, moderate and low dense human settlements, and further characterized based on the horizontal spacing between buildings, and the size and sanitary condition of storm water drains. The results identify vulnerable areas with information on surface runoff – thus facilitating the spatial targeting of intervention efforts. We found that room for flood waters is inadequate in terms of the capacity of storm water drains, and the land area left after human development. For storm water drains, the size is inadequate, their sanitary condition needs improvement, and their number need increasing based on catchment area. Informal and unstructured human settlements reduce the available room and artificially extend the flow path of runoff, which promotes flow accumulation thereby increasing the volume and destructive impact of flood waters. The study recommends intervention efforts to spatially target the creation of adequate room for flood waters to flow.

Prediction of the Variability of Changes in the Intensity and Frequency of Climate Change Reinforced Multi-Day Extreme Precipitation in the North-Central Vietnam Using General Circulation Models and Generalized Extreme Value Distribution Method

Flooding of downstream agricultural fields and cities is normally caused by consecutive days of extreme precipitation in upstream areas. As climate change is widely projected to accelerate the hydrological cycle, concerns about the increase in frequency and intensity of extreme precipitation arise. The present study used Pattern Scaling coupled with Generalized Extreme Value (GEV) distribution to calculate changes in multi-day extreme precipitation in the North Central Vietnam in 2050, 2070, and 2090 under three AR5’s Representative Concentration Pathways RCP2.6, RCP6.0 and RCP8.5. Twenty long-term historical observation stations in the study area with daily data mostly date back to more than 50 years were employed and 5-day maximum total precipitation was analyzed. The results reveal an agreement among the employed GCMs on an increase in the intensity and a shortening of the return periods of extreme precipitation, with the most reinforced trend occurring under RCP8.5, followed by RCP6.0 and then RCP2.6. This indicates that the risk of associated floods is likely to increase, especially under higher RCPs. Therefore, planning and decision making of durable infrastructure along with flood mitigation strategies to cope with such events are recommended.

Index-based Approach to Evaluate City Resilience in Flooding Scenarios

Intense rainfall events combined with high tide levels frequently result in urban floods in riverine or coastal cities. Their increasing variability and uncertainty demand urgent but sustained responses. Thus, resilience-driven approaches are emerging in contrast to the traditional technical-economic frameworks, as urban resilience reflects the overall capacity of a city to survive, adapt and thrive when experiencing stresses and shocks. This paper presents a simplified index-based methodology for the evaluation and quantification of urban resilience to flooding, based on the works developed in the EU H2020 RESCCUE project. A set of five indicators are proposed to compute the Integrated Urban Resilience Index (IURI), allowing to classify resilience according to a proposed range of rankings. This methodology considers simultaneously a multisectoral approach, reflecting services interdependences, and a sectorial approach, applying 1D/2D computational modelling of the urban drainage network. It was applied to the study case of Lisbon downtown, involving the analysis of interdependencies between 124 infrastructures of 10 urban services. Two scenarios were considered, respecting the current and future situations, considering climate changes. Results enhance the usefulness, practicability, and potential of the proposed approach, and improvement opportunities were also identified for future developments. Doi: 10.28991/cej-2021-03091647 Full Text: PDF

Characterization of fuel oil from pyrolysis waste light density polyethylene (LDPE) and polypropylene (PP)

Plastic is the biggest commonly used materials in daily life. The increased of use plastics in daily life like due to their light weight, good durability, corrosion resistance, and is quite economical. However, plastic is stable and difficult to degrade so it can cause pollution to soil and also water ecosystems. Plastic waste for many years has been one of the main causes of flooding in several cities in Indonesia. Pyrolysis is one of environmentally friendly technologies that can be a solution to the plastic waste problem. Pyrolysis can convert plastic waste into liquid fuel by thermal degradation. This research aims to synthesize liquid materials from LDPE and PP plastic waste using pyrolysis and study the effect of variations in plastic types. Pyrolysis temperature used is 325 °C in 4 hours. The fuels obtained were analysed in nature including density, viscosity, flash point. Fuel content was analysed using GC-MS devices. The result of research was highest viscosity (0.61 cSt) and density (820K kg m−3) found at 100% PP plastic waste pyrolisis. 100% LDPE composition produced liquid oil with the highest yield on a value of 26.23% and the highest gas yield obtained at 75% LDPE composition and 25% PP (64.44%). Pyrolysis of plastic LDPE and PP produced cyclohexanedione compounds (C9H14O2) with a fairly low percentage.

ИНЖЕНЕРНЫЕ ПРОЕКТЫ РУССКОЙ АРМИИ ПО ЗАТОПЛЕНИЮ РЕК В ГОДЫ ПЕРВОЙ МИРОВОЙ ВОЙНЫ: ПРОЕКТЫ И РЕАЛЬНОСТЬ

World War I, as a total conflict, was accompanied by various manifestations of the barbarization of hostilities. One of the topical issues of the world confrontation is its impact on the ecology of the region of military conflict. Written on the basis of archival materials for the first time used in studying, the article traces the policy of the military leadership on the use of water resources during the war. Various plans and measures for flooding areas in the system of passive and active defense in different points of the theater of military operations are analyzed: in the defense of fortresses, construction of barriers on rivers to prevent their forcing, attempts to use river barriers for flooding of entire cities. The work studies the reasons for the successes and failures of such plans. In particular detail it does so in the context of the plan to flood the rivers of Polesye, which was the largest reservoir of water resources in the western borderlands of Russia in a strategic region of historical confrontation between Russia and its western neighbors. The article concludes that there was a serious disagreement between the military and civilian authorities on the issue of the detrimental effects of river flooding to the agriculture, population, and ecology of the area, including in the postwar perspective, which forced the military leadership to adopt a moderate defense plan for swamping the area. In the course of using water resources, the Russian army managed to avoid the barbarization of military actions, including flooding large contingents of the enemy, limiting itself to moderate measures of impact on the ecology of the region and remaining within the limits of humanity, as far as total war permitted.

Risk Assessment of Flood Disaster in Linyi City Based on GIS

With the continuous acceleration of the urbanization process, the flood problem seriously affects the economic and social development of the city and the daily life of citizens. Therefore, taking Linyi City as an example, the flood disaster risk assessment is carried out, the Linyi City flood disaster assessment index system is constructed, and the methods of mathematical statistics, analytic hierarchy process and spatial overlay analysis are used to calculate the environmental sensitivity of Linyi City flood disasters with the help of GIS technology. , Risk of hazard factors, vulnerability of hazard-bearing bodies, disaster prevention and mitigation capabilities. The research results show that the hazard levels of flood disasters are increasing from west to east, and high-risk areas are distributed in Feixian and Junan counties; sensitivity is affected by topography and gradually increases from north to south; Lanshan District, Luozhuang District, etc. The city center is highly vulnerable due to its significant population and economic status, and has strong disaster prevention and mitigation capabilities.

Analysis of Flood Damage in the Seoul Metropolitan Government Using Climate Change Scenarios and Mitigation Technologies

The social and economic damages caused by climate change have increased rapidly over the last several decades, with increasing instances of heatwaves, floods, and extreme rainfall. In 2011, heavy rain of 110.5 mm/hr caused great damage to the Seoul Metropolitan Government. Most of the causes of flooding in modern cities include a sharp increase in non-permeable pavement and a lack of water circulation facilities. It is predicted that heavy rainfalls will occur in the future, causing large amounts of local damage. In this study, possible future flood damages were analyzed using climate change scenarios based on the Korean Peninsula. ArcGIS was adopted to perform analyses, and Huff curves were employed for precipitation analysis. Water tanks, permeable pavement, and ecological waterways were installed as mitigation technologies. These three technologies can contribute to flooding mitigation by increasing the rainwater storage capacity. This study suggests that all floods can be reduced by RCP 8.5 by 2050 and 2060. Although there will be run-off after 2050, it is believed that technology will significantly reduce the volume and possibility of floods. It is recommended that a one-year analysis should be conducted in consideration of the maintenance aspects that will arise in the future.

Instrumentos legais como ferramentas para redução de riscos e desastres a inundações

Inundações urbanas são frequentes, porém com adensamento urbano e a impermeabilização da terra (consequência e probabilidade), tendem a elevar o risco de desastres. Buscando reduzir este risco, o objetivo desta pesquisa é analisar como os instrumentos legais estão potencializando ou mitigando o risco de inundações nas principais cidades da Bacia Hidrográfica do Itajaí. Para alcançar este objetivo, realizou-se uma pesquisa descritiva nos Planos Diretores e em legislações municipais de Rio do Sul, Blumenau e Itajaí, com foco intra-lote, analisando os índices urbanísticos, em especial taxa de ocupação e taxa de permeabilidade. Estes índices foram relacionados com o mapa de zoneamento e quantificados em termos de município, sendo então possível uma análise comparativa. Utilizou-se também o zoneamento dos municípios para uma sobreposição aos mapas de áreas inundáveis. Os resultados demonstram que o município de Itajaí possui as maiores taxas de ocupação permitidas e as menores taxas de permeabilidade exigidas. Em relação as áreas inundáveis, os municípios de Rio do Sul e Itajaí possuem zonas com incentivo a ocupação dentro de áreas suscetíveis a inundações. Além disso, como outras medidas intra-lote para retardar o escoamento superficial de águas pluviais, apenas Blumenau possui legislação específica ao incentivar o uso de "Telhado verde". Portanto, conclui-se que as legislações municipais dos municípios analisados não têm incentivado a sustentabilidade urbana e que seus índices urbanísticos estão contribuindo para a ampliação do risco de desastre a inundações.

The Bearing and Breakage Characteristics of Crushed Stone Aggregates in the Bedding Course of Permeable Roads

The current study of permeable roads helps address urban flooding in Chinese cities caused by frequent heavy rainfall and build smart cities with sponge-like functionality. Crushed stone is widely used in constructing the bedding course of permeable roads because it has good water permeability. Experiments on the compaction of crushed stone were carried out by considering the impact of particle size and gradation to examine the strength and particle breakage characteristics of crushed stone and evaluate its use as the aggregate in the bedding course of permeable roads. The compaction process can be divided into two stages, i.e., the preliminary compaction stage and the particle crushing and intensive compaction stage. The latter consists of an alternating cycle of compacting and crushing. The particle size distribution after crushing can be described analogously to the Talbot continuous gradation equation. Single particle size samples are subject to earlier and stronger particle breakage than the mixed particle size sample, which are affected by both compaction level and loading speed. This study has important application value, and it provides experimental support for the study of materials for urban permeable roads.

Investigating an Innovative Sea-Based Strategy to Mitigate Coastal City Flood Disasters and Its Feasibility Study for Brisbane, Australia

This study examines an innovative Coastal Reservoir (CR) technique as a feasible solution for flood adaptation and mitigation in the Brisbane River Estuary (BRE), Australia, which is vulnerable to coastal flooding. The study analysed the operation of a CR by using the MIKE 21 hydrodynamic modelling package. The 2D hydrodynamic model was calibrated and validated for the 2013 and 2011 flood events respectively, with a Nash-Sutcliffe coefficient (Ens) between 0.87 to 0.97 at all gauges. River right branch widening and dredging produced a 0.16 m reduction in water level at the Brisbane city gauge. The results show that by suitable gate operation of CR, the 2011 flood normal observed level of 4.46 m, with reference to the Australian Height Datum (AHD) at Brisbane city, could have been reduced to 3.88 m AHD, while under the improved management operation of the Wivenhoe Dam, the flood level could be lowered to 4 m AHD at Brisbane city, which could have been reduced with CR to 2.87 m AHD with an overall water level reduction below the maximum flood level. The results demonstrated that the innovative use of a CR could considerably decrease the overall flood peak and lessen flood severity in the coastal city of Brisbane.

Effect of Change in Land-use to High Pattern of Inundation on Sub-River System of Lowland Urban River

Flooding is a temporal condition of surface water where the level and debit are exceeding a specific allowable limit. Urban city flooding is an effect of unbalance city environment related to regulation function. Vulnerability to increasing of population and change of land use at rural area and urbanisation to the flood-prone area, illegal shelter, land development on the water catchment area, increase in population density are the most common source of flooding on an urban area. This paper presents a study on the effect of changing in land use to high inundation pattern on river sub-system (SRS) of Bendung River in Palembang City. The data is taken based on a digital elevation model (DEM) generated from high point data set from a Compact Airborne Spectrographic Imager (CASI) sensor. The model used in this study was a hydrological model using SMADA 6.0 and DUFLOW 3.6 for rainfall-runoff model and analysis of river system generating surface water profile. The ArcGIS was used to construct a surface water model related to DEM data to obtain inundated area, inundation maps, inundation height and geospatial analysis. Four scenarios are applied in this study area which was changing the type of land use to a green area, changing the type of land use to a settlement area, free up 30 m riverbank to a green area and free up 100 m riverbank to a green area. From this study, the change in runoff coefficient, C value does not significantly reduce the inundation area in the area with more than 80% relatively flat topography. Increase the C value by 10% resulted in an increase on the puddle area to 9.4%, while the flood area with an altitude of more than 1 m increased to 359%. The results of scenario with land used change 10% - 20%, contributed to the increase in the flood area of 9.4% - 12.1%. So that to reduce the high pattern inundation a structural approach combined with a non-structural approach should be enforced and implemented. Besides, land-use changes will be significant to reduce flooding when land consolidation is applied to a sub-river system (SRS).

Rapid Urbanization Impact on the Hydrological Processes in Zhengzhou, China

Changes in the hydrological process caused by urbanization lead to frequent flooding in cities. For fast-growing urban areas, the impact of urbanization on the hydrological process needs to be systematically analyzed. This study takes Zhengzhou as an example to analyze the impact of urbanization on the hydrological process based on 1971–2012 hourly rainfall-runoff data, combining Geographic Information Systems with traditional hydrological methods. Our study indicates that the rain island effect in different districts of city became stronger with the increase of its built-up. The uneven land use resulted in the difference of runoff process. The flood peak lag was 25–30% earlier with the change of land use. The change of flood peak increased by 10–30% with the change of built-up. The runoff coefficient increases by 20–35% with the increase of built-up, and its change increased with the change of land use. Affected by the rain island effect, precipitation tends to occur in areas where built-up is dominant, which overall magnifies the impact of urbanization on the hydrological process. This provides new ideas for urban flood control. Refine flood control standards according to regional land use changes to cope with the hydrological process after urbanization.

Hydrological response to climate change and human activities: A case study of Taihu Basin, China

Climate change and human activities have changed a number of characteristics of river flow in the Taihu Basin. Based on long-term time series of hydrological data from 1986 to 2015, we analyzed variability in precipitation, water stage, water diversion from the Yangtze River, and net inflow into Taihu Lake with the Mann-Kendall test. The non-stationary relationship between precipitation and water stage was first analyzed for the Taihu Basin and the Wuchengxiyu (WCXY) sub-region. The optimized regional and urban regulation schemes were explored to tackle high water stage problems through the hydrodynamic model. The results showed the following: (1) The highest, lowest, and average Taihu Lake water stages of all months had increasing trends. The total net inflow into Taihu Lake from the Huxi (HX) sub-region and the Wangting Sluice increased significantly. (2) The Taihu Lake water stage decreased much more slowly after 2002; it was steadier and higher after 2002. After the construction of Wuxi urban flood control projects, the average water stage of the inner city was 0.16–0.40 m lower than that of suburbs in the flood season, leading to the transfer of flooding in inner cities to suburbs and increasing inflow from HX into Taihu Lake. (3) The regional optimized schemes were more satisfactory in not increasing the inner city flood control burden, thereby decreasing the average water stage by 0.04–0.13 m, and the highest water stage by 0.04–0.09 m for Taihu Lake and the sub-region in the flood season. Future flood control research should set the basin as the basic unit. Decreasing diversion and drainage lines along the Yangtze River can take an active role in flood control.

Ensuring the civil security in territorial entities

Subject. As the society faces more and more threats and risks, civil security issues become a priority. The civil security means the protection of a citizen from external and internal threats arising from the societal, natural and technological environments. Objectives. The study evaluates threats and civil security in territorial units. Methods. I applied methods of the comparative analysis, results of sociological surveys and official statistics. Results. What seems to put people at peril at the local level is mushrooming threats of emergencies. Evaluating the security of the urban environment, I should point out low road accident rates, good fire safety, more preventive public security actions for people and businesses. In the mean time, I mention weaknesses, such as buildings in residential areas that can be destroyed by land slides, residential areas exposed to karst hazards, floods in cities and houses during spring tides, few people having access to central communication channels, its obsolescence, low capacity and insufficient ramification of sewage networks, etc. Conclusions and Relevance. There should be a conceptual smart city model, which would refer to the public feedback on the urban environment. At the municipal level, I should prioritize the improvement of emergency prevention practices, expansion and development of video surveillance in publicly important places, air pollution monitoring, rehabilitation of the existing sewage network, geological surveys of karst hazards in urban areas, etc.

Matching analysis of investment structure and urban inundation control function of sponge cities in China

The risk of urban flood inundation has been increasing worldwide. To address this problem, the sponge city strategy has been proposed in China. This study focuses on the issue of urban flood inundation, which is a main problem that the construction of sponge cities seeks to address. The design mode of sponge city flood control and drainage systems (SCFCDSs) is examined, including source control systems (SCSs), stormwater pipe network systems (SPNSs), and over-standard stormwater storage and drainage systems (OSSSDSs). A quantitative method to evaluate flood control and drainage capacity (stormwater equivalent) of SCFCDSs is proposed and applied to quantitatively analyze the matching relationship between investment structure and inundation control function. Based on 18 pilot cities, the stormwater equivalents of the SCSs, SPNSs, and OSSSDSs account for 13.8, 57.7, and 28.6% of the stormwater equivalent of SCFCDSs on average, respectively. On the other hand, the investments in SCSs, SPNSs, and OSSSDSs account for 66.1, 15.0, and 18.9% of the total investment in SCFCDSs on average, respectively. The results show that an unbalanced investment structure and corresponding design standards along with insufficient investment in OSSSDSs are the key factors hindering the effective implementation of urban flood inundation control in sponge cities.

Integration between Torrent Protection Gray Infrastructures with Constructed Wetland to Achieve Resilience in Ras Gharib

Flooding and torrents are a seasonal phenomenon that hit a lot of cities every year around the world. As climate changes affect the world, cities are increasingly exposed to such threats especially those located on flood streams are most exposed to damages in the winter and the flooding season. In the past ten years, Egypt has been facing severe climate change effects like the increasing frequency of flooding in Egyptian cities. According to the Egyptian government, there are more than 1200 Egyptian cities and villages on flood streams and torrent tracks. These cities are distributed between the Mediterranean coast, Cairo region, Red Sea coast, Sinai and Upper Egypt, these and increasingly vulnerable towards the floods and their urban life is severely affected weather in old cities or in new planned cities. It is mostly located in the Eastern Desert at the east of the Nile. According to geologists and Meteorologists, these cities and their inhabitants are facing future hazards if they were not well prepared to handle floods. The international experience in constructed wetland projects proved to be a successful technique maintaining floods and turning it into sources of development and increasing biodiversity. Several countries led by China have developed national strategies to use wetland parks as a defense tool against flood risks, at the same time these parks have become a source of income for their cities. This paper is a part of series of papers and researches for constructed wetland technology and opportunities to use it in Egypt. In this paper, the torrents and flood risks facing Ras Gharib city will be highlighted. Explaining the abilities of constructed wetland parks to minimize the damage and transform it into a source of strength, which will be a part of resilience city new policies. The research method is a comparative analysis between international project strategies and the Egyptian current strategies and actions to face flood and torrent risk. It will be the fundamentals of an Egyptian model that is compatible with the city's risks and challenges.

Increasing Coastal Disaster Resilience Using Smart City Frameworks: Current State, Challenges, and Opportunities

Sea-level rise, storm surges, and floods in coastal cities have already threatened large population and infrastructure with potential to increase significantly in future as climate changes. Therefore, increasing disaster resilience has become a major priority for coastal cities. At the same time, recent development in information and communication technology, ubiquitous sensors, and advanced data science allow us to generate insights that were unimaginable before and can assist in better managing coastal disaster risks. In this paper, using an infrastructure resilience lens, we critically review a set of academic literature that focus on the new development of smart systems in coastal disaster management and a set of use cases that focus on their practical application in different coastal cities. We find that smart city technologies such as internet of things (IoT) and crisis informatics have significant potential and have been increasingly used in academic studies but their city-scale applications in coastal disaster management have been limited. We discuss the challenges and opportunities of using smart city frameworks for increasing disaster resilience of coastal communities.

Electrical Grid Risk Assessment Against Flooding in Barcelona and Bristol Cities

Climate change is increasing the frequency and intensity of extreme events and, consequently, flooding in urban and peri-urban areas. The electrical grid is exposed to an increase in fault probability because its infrastructure was designed considering historical frequencies of extreme events occurred in the past. In this respect, to ensure future energy plans and securing services is of great relevance to determine and evaluate the new zones that may be under risk and its relation to critical infrastructures for such extreme events. In this regard, the electrical distribution system is one of the key critical infrastructures since it feeds the others and with the future plans of zero-emissions (leading to the electrification of transport, buildings, renewable energies, etc.) will become even more important in the short term. In this paper, a novel methodology has been developed, able to analyze flood hazard maps quantifying the probability of failure risk of the electrical assets and their potential impacts using a probabilistic approach. Furthermore, a process to monetize the consequences of the yielded risk was established. The whole method developed was applied to the Barcelona and Bristol case study cities. In this way, two different examples of application have been undertaken by using slightly different inputs. Two main inputs were required: (1) the development of accurate GIS hazard flooding models; and (2) the location of the electrical assets (i.e., Distribution Centers (DCs)). To assess and monetize the flood risk to DCs, a variety of variables and tools were required such as water depths (i.e., flood maps), DCs’ areas of influence, fragility curves, and damage curves. The analysis was performed for different return periods under different scenarios, current (Baseline) and future (Business As Usual (BAU)) rainfall conditions. The number of DCs affected was quantified and classified into different categories of risk, where up to 363 were affected in Barcelona and 623 in Bristol. Their risk monetization resulted in maximums of 815,700 € in Barcelona and 643,500 € in Bristol. Finally, the percentage of risk increases when considering future rainfall conditions (i.e., BAU) when calculated, resulting in a 2.38% increase in Barcelona and 3.37% increase in Bristol, which in monetary terms would be an average of a 22% increase.

Interpretation and application of Sponge City guidelines in China.

'Sponge City' is the term used to describe the Chinese government's approach to urban surface water management. The concept was conceived in 2014 in response to an increasing incidence of urban flooding or water-logging in Chinese cities. While ambitious and far-reaching in its aim (of decreasing national flood risk, increasing water supply and improving water quality), the initiative must be implemented by individual subprovincial or municipal-level government entities. Thus, while the concept is similar to sustainable drainage systems (SuDS) in the UK (or low-impact development (LID) in the USA), it is developing with different regional characteristics, and during continuing rapid urbanization. Indeed, the increasing use of national rather than international examples of best practice reflects a growing body of knowledge that has evolved since the start of the Sponge City initiative. In this paper, interpretation and development of the national Sponge City guidelines are assessed for the Ningbo Municipality, an affluent and rapidly expanding city on China's low-lying east coast. While climate, geology and socio-economic factors can all be seen to influence the way that national guidelines are implemented, project financing, integration and assessment are found to be of increasing influence. This article is part of the theme issue 'Urban flood resilience'.

Quantifying Extreme Precipitation Forecasting Skill in High-Resolution Models Using Spatial Patterns: A Case Study of the 2016 and 2018 Ellicott City Floods

Recent historic floods in Ellicott City, MD, on 30 July 2016 and 27 May 2018 provide stark examples of the types of floods that are expected to become more frequent due to urbanization and climate change. Given the profound impacts associated with flood disasters, it is crucial to evaluate the capability of state-of-the-art weather models in predicting these hydrometeorological events. This study utilizes an object-based approach to evaluate short range (<12 h) hourly forecast precipitation from the High-Resolution Rapid Refresh (HRRR) versus observations from the National Centers for Environmental Prediction (NCEP) Stage IV precipitation analysis. For both datasets, a binary precipitation field is delineated using thresholds that span trace to extreme precipitation rates. Next, spatial metrics of area, perimeter, solidity, elongation, and fragmentation, as well as centroid positions for the forecast and observed fields are calculated. A Mann–Whitney U-test reveals biases (using a confidence level of 90%) related to the spatial attributes and locations of model forecast precipitation. Results indicate that traditional pixel-based precipitation verification metrics are limited in their ability to quantify and characterize model skill. In contrast, an object-based methodology offers encouraging results in that the HRRR can skillfully predict the extreme precipitation rates that are anticipated with anthropogenic climate change. Yet, there is still room for improvement, since model forecasts of extreme convective rainfall tend to be slightly too numerous and fragmented compared with observations. Lastly, results are sensitive to the HRRR model’s representation of synoptic-scale and mesoscale processes. Therefore, detailed surface analyses and an “ingredients-based” approach should remain central to the process of forecasting excessive rainfall.