Flood Risk Reduction Research Articles

Risk-Reduction, Coping, and Adaptation to Flood Hazards in Manitoba, Canada: Evidence from Communities in the Red River Valley

In general, much is known about patterns relating to flood risk reduction, coping, and adaptation in various types of communities; however, knowledge of their drivers—which are critical for building community resilience to natural hazards—is limited. The present study investigates the influencing factors of coping and adaptation measures vis-a-vis flood hazards at the community level and examines their interrelationships. This work employs a “case study” approach and analyzes two towns—St. Adolphe and Ste. Agathe—in the Red River Valley in the province of Manitoba, Canada. Data collection consisted of in-depth interviews with key informants and obtaining oral histories from the locals, along with an examination of secondary official records and documents. The results revealed that the major drivers of local-level coping and adaptation include functioning partnerships among stakeholders, strong institutional structures that facilitate interactive learning, knowledge co-production, resources sharing, communication and information sharing, and infrastructure supports. It was observed that an institutional atmosphere conducive to spontaneous network development yields diverse coping and adaptation strategies. To improve the outcomes of coping and adaptation measures, close collaboration between community-based groups and formal and quasi-formal institutions, and transparency in decision-making processes are vital.

Construction and application of sponge city resilience evaluation system: a case study in Xi’an, China

Urban vulnerability is evident when highly complex flood risks overlap with diverse cities, and it is important to enhance the resilience of cities to flood shocks. In this study, a sponge city resilience assessment system is established considering engineering, environmental and social indicators, and the grey relational analysis method (GRA) is used to quantify sponge city resilience. At the same time, a multi-objective optimization model is established based on the three dimensions of water ecological environment, drainage safety, and waterlogging safety. The optimal configuration of grey-green infrastructure is weighed by combining the ideal point method, aiming to ensure that cities effectively reduce flood risk through the optimal configuration scheme. Taking the Xiaozhai area in Xi'an as the study area, the evaluation results show that the grey relational degree (GRD) of the resilience indexes of the original scheme is between 0.390 and 0.661 under the seven different return periods, while the optimization scheme ranges from 0.648 to 0.765, with the best sponge city resilience at a return period of 2a. Compared with the original scheme, the optimized sponge city resilience level increases from level II to nearly level I in the low return period and from level IV to level II in the high return period, indicating that city's ability to cope with waterlogging and pollution is enhanced significantly. Besides, the main factor affecting the sponge city resilience is the runoff control rate, followed by pollutant load reduction rate, which can provide a methodological framework for the assessment and improvement of sponge city resilience.

Multi-objective Optimisation Framework for Assessment of Trade-Offs between Benefits and Co-benefits of Nature-based Solutions

Urbanization and climate change are producing an escalation in the prevalence of urban problems, particularly those connected to flooding, prompting authorities and stakeholders to recognize the need for sustainable solutions. Nature-Based Solutions are progressively replacing traditional engineering solutions as an alternative since they are more eco-friendly. By re-activating the urban hydrological cycle processes, NBS intends to increase the natural water storage capacity to help decrease urban flooding. The work described here outlines a framework for optimising the efficacy of NBS for flood risk reduction and its co-benefits, as well as defining the trade-offs among these co-benefits. The framework integrates 1D hydrodynamic models with multi-objective optimisation techniques. To demonstrate the applicability of the framework and its methods it has been used in Sint Maarten, which is an island located in the Caribbean Sea. Four NBS measure were identified as having good potential to be applied in the case study, namely: green roof, permeable pavement, bio-retention pond, and open detention basin. The results showed that the developed framework has the ability to represent the link between benefits and costs when evaluating various NBS, hence aiding the decision-making process to select and implement NBS.

Monsoon flood risks in urban areas of Pakistan: A way forward for risk reduction and adaptation planning

Climate change poses a significant threat to sustainable urban development. Heavy rainfall has led to severe urban flooding, disrupting human life and causing widespread damage. This study aims to examine the impacts, preparedness, and adaptation strategies related to monsoon flooding in Lahore, Pakistan's second-most populous metropolitan area. Using Yamane's sampling method, a total of 370 samples were surveyed and analyzed using descriptive analysis and chi-square tests. The results indicate that houses and parks were the most commonly damaged properties, with common impacts including roof collapse, house fires, seepage, and wall dampness. These impacts not only caused physical damage but also disrupted basic amenities and damaged roads, resulting in significant socioeconomic costs. Despite these challenges, residents adopted a variety of adaptation strategies such as the use of temporary tarps, moving household appliances to upper floors, and shifting to tiled floors and wall paneling to mitigate damage. However, the study highlights the need for further measures to reduce flood risks and promote adaptation planning in order to effectively address the ongoing challenges posed by climate change and urban flooding.

Incorporating technical and farmer knowledge to improve land use and management for natural flood management in lowland catchments

Natural flood management (NFM) involves measures to restore and protect natural hydrology and geomorphology to minimise flood risk. NFM is promoted as part of the nation’s flood resilience response. Government agencies have created national maps of opportunities for specific NFM measure to target available grant aid and encourage landowners and managers to deliver effective NFM measures where most needed. Mapping opportunities within a regulatory framework ensures that measures are targeted towards areas with a presumption of suitability thus minimising the burden of the application process.The viability of NFM depends on the responsible authority and community at risk accepting the proposed measures as both effective and appropriate. Top-down initiatives can fail to meet their targets when landowners and managers feel left out of the decision making and their experiential local knowledge is at odds with the spatial prioritisation derived from national datasets.This interdisciplinary paper assesses the applicability of a technical-based national mapping approach with local stakeholders for identifying opportunities for woodland and runoff management measures to reduce flood risk within the lowland catchments of the West Thames River Basin, in southern England. Farmer surveys supported the technical map in terms of targeting areas of deep clay and silt soils over mudstone as high priority for improved land and soil management to reduce rapid runoff. However, while incentives correctly target the problem areas, farmers desired greater flexibility in choice of NFM measures to reflect local soil knowledge and the sustainability of management practices within farm systems. It is argued that a more integrated and co-designed mapping approach would enhance NFM uptake and thus achieve a greater reduction in downstream flood risk.

Encouraging planting in urban front gardens: a focus group study.

Encouraging planting in front gardens offers mental and physical health benefits, as well as positive local environmental impacts such as reducing flood risk and improving air quality. However, urban front garden greenery has reduced in recent years. We aimed to explore adults' views regarding planting greenery in front gardens, barriers and facilitators, and their understanding of health and environmental impacts, to identify appropriate intervention mechanisms for behaviour change. We carried out five online focus groups with 20 participants aged 20-64 in England, purposively sampled for variation according to age, gender, home ownership, income, ethnicity and residing in an urban or suburban area. We audio recorded each focus group, transcribed it verbatim and analysed transcripts using thematic analysis. Front gardening was a relaxing activity that provided benefits including increased wellbeing, fresh air and vitamin D. Planting in front gardens depended heavily on available time and space, garden orientation, local security and the weather. Front gardens could be a place for social interaction. Participants tended to prioritise neatness and tidiness over greenery. Lack of knowledge and low self-efficacy were key barriers. There was little awareness of the environmental benefits of front garden greenery; however, reducing flood risk and encouraging biodiversity were viewed positively. Initiatives to encourage front garden planting should focus on plants that require little knowledge to acquire and care for, are suitable to the local environmental conditions and with a visual impact of neatness and bright colour. Campaigns should draw attention to local flood risk reduction and increasing biodiversity, in addition to personal health benefits.

Effects of Storm Surge Barrier Closures on Estuary Saltwater Intrusion and Stratification

AbstractGated storm surge barriers have been constructed or proposed in many estuaries worldwide for coastal flood risk reduction. Past studies have shown that, even when open, a barrier system's fixed infrastructure can increase estuary stratification and salt intrusion, potentially affecting water quality and ecological processes. However, surge barrier closures could have a much stronger influence on estuary conditions by temporarily blocking the tidal exchange. In this project, we use an existing regional three‐dimensional hydrodynamic model, with modifications to simulate surge barrier closure and reopening, to study the effects on estuarine salt intrusion and stratification of the Hudson River. Across a range of modeled scenarios of gate closure frequencies, durations and river streamflows, we evaluate the changes caused by gate closures, as well as the recovery time to normal conditions. Our results for the Hudson show long‐duration gate closures (three or more days) with low streamflows temporarily lead to salt intrusion and stratification beyond recent historical extremes. Moreover, monthly frequency closures, which could occur as soon as 2070 under realistic scenarios of sea‐level rise and barrier management, do not allow for recovery under low streamflow conditions and could lead to durable changes to estuary physical conditions. As a result, long duration closures and high‐frequency closures both constitute a threat to municipal water supplies. This study demonstrates a framework for understanding the potential impacts of any proposed surge barrier system and can help improve our understanding of corresponding ecological impacts.

Floods and Adaptation to Climate Change in Tourist Areas: Management Experiences on the Coast of the Province of Alicante (Spain)

One of the principal challenges for cities on the Mediterranean coast is the management of urban runoff after episodes of intense rainfall. This problem is aggravated by the effects of climate change, with the increase in the frequency and intensity of extreme weather phenomena in this region. In light of this situation, the local governments, in collaboration with the concessionaire companies providing supply and sewage services, are committed to adopting measures aimed at a more efficient management of non-conventional water resources. Examples of good practice for reducing urban flood risk and adapting to climate change are those actions developed in the tourist municipalities of Alicante, Torrevieja, and Benidorm, where measures have been implemented or have been planned and integrated with green spaces, with a commitment to sustainability, such as sustainable urban drainage systems (SUDS) or Nature-Based Solutions (NBSs). This study analyses these case studies, based on a detailed review of the technical projects that contemplate each of the actions. Furthermore, several field trips were made with technical personnel who are familiar with the measures adopted. The results show that the implementation of these systems contributes to advancing the reduction of urban flood risk and the adaptation to climate change, creating more resilient and safer urban spaces for the citizens residing in them.

Flood Hazard Mapping Using a Multi-Criteria Decision Analysis Approach Over the Indrawati River Basin

Floods are devastating natural hazard responsible for direct mortality, deterioration of crops, and damage to infrastructure and property. So, their study is crucial for watershed management and mitigation of flood hazards. The main objective of this study was to create a scientifically valid flood hazard map of the Indrawati River Basin (IRB) through the use of the multi-criteria decision analysis approach. Topographical Wetness Index (TWI), Elevation (EL), Slope (SL), Precipitation (PPT), Land Use/Land Cover (LULC), Normalized Difference Vegetation Index (NDVI), Distance from the River (DRI), Distance from the Road (DRO), Drainage Density (DD), and Soil Type (ST) were chosen as flood triggering factors based on literature review, data availability, and catchment characteristics. The analytic hierarchy process (AHP) method was used for determining the relative weight of each flood causative factor. All these factors were resampled into a 30 m × 30 m pixel size. Based on an evaluation of satellite imagery, 30 flood points were identified in the IRB, and these points were used as the testing dataset for validating the outcome. Based on results, the IRB has been classified into five different flood susceptible zones; very low, low, moderate, high, and very high. According to the study, 13%, 26%, 30%, 23%, and 8% of the total area are in very low, low, moderate, high, and very high flood susceptible zones, respectively. The Area Under the Curve (AUC) value for the success rate was 0.792. The results of this study will be crucial for concerned parties to design early warning systems and flood risk reduction measures for flood preparedness.

Experimental investigation of a multilayer detention roof for stormwater management

This study aimed to evaluate the technical feasibility of a multilayer detention roof, namely a purple roof, in managing urban stormwater. A purple roof is conceptually and technically different from a green roof in that the former includes a low-transmissivity drainage layer and a void layer that can be designed at various depths for the temporary storage and slow release of water. Three types of roofs, i.e., (i) traditional, (ii) green and (iii) purple, were constructed in Western Sydney, Australia. These roofs were investigated and compared in terms of runoff reduction capacity, time to start runoff and time to release the runoff. Data were collected across the period from April 2021 to May 2022. A total of 76 rainfall events were recorded during this period. It was found that the purple roof performed better than other roof systems during all the rainfall events. The purple roof delayed the median start times of runoff by 773, 211 and 86 min for small, medium and large rainfall events, respectively, compared to a traditional roof, and 110, 59 and 14 min, respectively, compared to a green roof. During small rainfall events, the purple roof retained 100% of the water on most occasions. For medium, large, and extremely large events, the median runoff volume reductions by the purple roof were 88%, 34% and 7%, and 55%, 21% and 10% than those of the traditional and green roofs, respectively. In addition to reducing the volume discharged, the purple roof took 242 and 113 min (median values) longer to discharge the stormwater compared to the traditional roof during medium and large events, respectively, and 226 and 66 min (median values) longer than the green roof. In the case of median times for extremely large events, the purple roof took 503 min longer to release stormwater than the traditional roof, and 74 min longer than the green roof. The outcomes from this study proved the technical feasibility of the purple roof technology to slow the release and reduce the volume of stormwater during different-sized rainfall events. Thus, a purple roof can potentially be used to replace the traditional detention basins in a dense urban environment to reduce flood risks.

Comprehensive Flood Risk Assessment: State of the Practice

A comprehensive assessment of flood hazards will necessitate a step-by-step analysis, starting with hydrometeorological examinations of runoff and flow, followed by an assessment of the vulnerability of those at risk. Although bodies of knowledge about these topics are large, flood risk assessments face data challenges such as climate change, population growth, and shifting land uses. Recent studies have provided comprehensive reviews of advances in the water sciences arena, and in a complementary way, this paper reviews the state of the practice of assessing flood risk, include flood scenarios, hydrometeorology, inundation modeling, flood frequency analysis, interrelationships with water infrastructure, and vulnerability of people and places. The research base for each of these topics is extensive. Some of the tools in these areas, such as hydrologic modeling, have research advances that extend back decades, whereas others, such as numerical weather prediction, have more room to evolve. It’s clear from all studies that data is crucial along the progression from atmospheric conditions to the impact on flood victims. How data are provided and shared and how they are used by stakeholders in flood risk reduction continue to evolve. Improved availability of data and uses of emerging tools of data science and machine learning are needed to assess and mitigate flood risks. Continued the development of key tools is also required, especially to improve the capability to assemble them effectively on user platforms.

Suitability Assessment of Small Dams’ Location as Nature-Based Solutions to Reduce Flood Risk in Mataniko Catchment, Honiara, Solomon Islands

As global temperatures rise, flooding and storm surges caused by extreme weather threaten people’s safety and nations’ development. Nature-based Solutions (NBS) are practical actions to support resilience to reduce flood risk and are applied in many countries. As the NBS approach mentions, small check dams made of gabion and wood can retain runoff and temporarily create detention basins to reduce the magnitude of floods and provide additional water resources. However, previous dam suitability research emphasized the criteria selection and decision method evolution, which costs time on the complex calculation and does not fit the NBS small dams. This research aims to optimize the site selection workflow of small dams in vulnerable informal settlements by utilizing Remote Sensing (RS), Geographic Information Systems (GIS), and Multi-Criteria Evaluation (MCE). Several thematic layers, such as land use, river density, building distance, vegetation cover index, slope, and elevation factors, were chosen to identify the suitable area in Mataniko catchment, Honiara. More importantly, it provides a more efficient model builder that can be replicated in ArcGIS 10.8, which contributes to visualizing scenarios of the inundation area of small dams at different heights. As a result, this study tested up to 35 potential small dams with 2.5 and 5 m wall height in the flood-prone Vara Creek and selected nine small dams with 5 m height and 15 small dams at 2.5 m as the best locations according to the volume and area. Overall, it is an efficient tool for designers to communicate with different stakeholders and applies to other developing countries facing frequent floods. Moreover, it provides a prototype and evidence of NBS action to address the flood issue.

Flood Resilience Assessment and Mapping: A Case Study from Australia’s Hawkesbury-Nepean Catchment

Floods are the most common and costliest natural hazard in Australia. However, the Flood Resilience Assessments (FReAs) employed to manage them lack a focus on adaptive capacity and tend not to be incorporated into established flood risk frameworks. This leaves potential for Australian FReAs to make better use of a methodology which holistically incorporates more accurate flood resilience characterisations into flood risk frameworks. In this study, a FReA and mapping for the Hawkesbury-Nepean Catchment (HNC), a flood-prone region in Australia, were conducted. Nine flood resilience indicators were selected to derive the Flood Resilience Index (FReI). Results demonstrated that Statistical Areas Level 2 (SA2s) on or near the floodplain, located near the eastern border of the HNC, present moderate to very high levels of resilience due to increased socio-economic development and urbanisation in the region. Ultimately, this novel FReI can contribute to knowledge bolstering flood resilience in the HNC, as well as assist in flood risk reduction. Additionally, the developed scalable and replicable methodology can be applied to other flood-prone regions of Australia.

Automatic Extraction of Flooding Control Knowledge from Rich Literature Texts Using Deep Learning

Flood control is a global problem; increasing number of flooding disasters occur annually induced by global climate change and extreme weather events. Flood studies are important knowledge sources for flood risk reduction and have been recorded in the academic literature. The main objective of this paper was to acquire flood control knowledge from long-tail data of the literature by using deep learning techniques. Screening was conducted to obtain 4742 flood-related academic documents from past two decades. Machine learning was conducted to parse the documents, and 347 sample data points from different years were collected for sentence segmentation (approximately 61,000 sentences) and manual annotation. Traditional machine learning (NB, LR, SVM, and RF) and artificial neural network-based deep learning algorithms (Bert, Bert-CNN, Bert-RNN, and ERNIE) were implemented for model training, and complete sentence-level knowledge extraction was conducted in batches. The results revealed that artificial neural network-based deep learning methods exhibit better performance than traditional machine learning methods in terms of accuracy, but their training time is much longer. Based on comprehensive feature extraction capability and computational efficiency, the performances of deep learning methods were ranked as: ERNIE > Bert-CNN > Bert > Bert-RNN. When using Bert as the benchmark model, several deformation models showed applicable characteristics. Bert, Bert-CNN, and Bert-RNN were good at acquiring global features, local features, and processing variable-length inputs, respectively. ERNIE showed improved masking mechanism and corpus and therefore exhibited better performance. Finally, 124,196 usage method and 8935 quotation method sentences were obtained in batches. The proportions of method sentence in the literature showed increasing trends over the last 20 years. Thus, as literature with more method sentences accumulates, this study lays a foundation for knowledge extraction in the future.

Cost-benefit analysis of local knowledge-based flood adaptation measures: A case study of Datian community in Zhejiang Province, China

Adaptation measures are important to deal with rising flood risk under a changing climate. Measures based on local knowledge (LK) is of great significance for communities to live with flood risks. However, the analysis on their costs and benefits is often overlooked. In this study, participatory GIS (PGIS) is used to explore LK in a flood-prone community in Zhejiang Province, China. By incorporating flood risk analysis, we apply the net present value (NPV) method to quantify the costs and benefits of LK-based flood adaptation measures (FAMs) (i.e., the wet-floodproofing, 0.5 m-uplift, 1.0 m-uplift and hybrid measures). Our results show that, the flood-prone community residents have gradually adopted FAMs through a series of flood experiences and learning processes. The LK-based FAMs can significantly reduce flood risk. With FAMs, the expected annual damage (EAD) decreases by 55.6–98.8%. All FAMs with three discount rates are feasible (NPV >0) regardless of short-, medium-, or long-term goals, of which the hybrid measure is the most desirable. Our work suggests that LK is beneficial in reducing flood risk and can be incorporated into decisions on resilient community building. Our approach can also be applied in other coastal communities for their cost-benefit analysis of LK-based FAMs.

The impact of multipurpose dams on the values of nature's contributions to people under a water-energy-food nexus framing

The paper proposes a probabilistic approach to the assessment of the impacts of multipurpose dams. It is framed around the notion of Nature's Contributions to People (NCP) in the setting of the Water-Energy-Food nexus. The socio-ecological context of the Tana River Basin in Kenya and the construction of two multipurpose dams are used to highlight co-produced positive and negative NCP under alternative river regimes. These regimes produce both damaging floods that ought to be controlled and beneficial floods that ought to be allowed. But the river regime that results from hydropower generation and flood risk reduction may not be the one that is most conducive to food and feed-based NCP. The approach relates the economic value of river-based NCP co-production to the probability of flooding to derive the expected annual value of NCP and a NCP value-probability curve. The relation between NCP flows and flood characteristics is tested and estimated based on regression analyses with historical data. Results indicate that the net economic value of key NCP associated with multipurpose dams for local people and associated social equity effects largely depend on the frequency of flood events and on the way impacts are distributed across communities, economic sectors and time.

Quantifying the fragility of coral reefs to hurricane impacts: a case study of the Florida Keys and Puerto Rico

Ecosystems like coral reefs mitigate rising coastal flood risks, but investments into their conservation remain low relative to the investments into engineered risk-mitigation structures. One reason is that quantifying the risk-reduction benefits of coral reefs requires an estimate of their fragility to severe stresses. Engineered structures typically have associated fragility functions which predict the probability of exceeding a damage state with the increasing loading intensity imposed by a stressor, like a hurricane. Here, we propose a preliminary framework for capturing the fragility of coral reefs towards hurricanes in an analogous way to that of an engineered structure. We base our framework on Disturbance Response Monitoring data collected in the Florida Keys and Puerto Rico following hurricanes Irma and Maria. We first establish a qualitatively consistent correlation between hurricane impacts and coral mortality rates using two surveys of coral health. We focus specifically on stony coral mortality as a metric for reef damage, simplifying the effect of coral morphology into a single quantitative index at the site scale. To quantify the loading intensity of a hurricane, we propose a Hurricane Wind Exposure Time that captures spatial variations in the exposure of different coral reef sites to hurricane force winds. We ultimately derive a simple empirical fragility function for the Florida Keys and Puerto Rico to support side-by-side comparisons of the cost-effectiveness of a coral reef and engineered solutions to flood risk reduction in these regions.

Climate and Human Impacts on Hydrological Processes and Flood Risk in Southern Louisiana

AbstractSatellite observations of coastal Louisiana indicate an overall land loss over recent decades, which could be attributed to climate and human‐induced factors, including sea level rise (SLR). Climate‐induced hydrological change (CHC) has impacted the way flood control structures are used, altering the spatiotemporal water distribution. Based on “what‐if” scenarios, we determine relative impacts of SLR and CHC on increased flood risk over southern Louisiana and examine the role of water management, via flood control structures, in mitigating flood risk over the region. Our findings show that CHC has increased flood risk over the past 28 years. The number of affected people increases as extreme hydrological events become more exceptional. Water management reduces flood risk to urban areas and croplands, especially during exceptional hydrological events. For example, currently (i.e., 2016–2020 period), CHC‐induced flooding puts an additional 73 km2 of cropland under flood risk at least half of the time (median flood event) and 65 km2 once a year (annual flood event), when compared to a past period (1993–1997). A 10‐ to 20‐fold increase relative to SLR‐induced flooding. CHC also increases population vulnerability in southern Louisiana to flooding; additional 9,900 residents currently live under flood risk at least half of the time, and that number increases to 27,400 for annual flood events. Residents vulnerable to SLR‐induced flooding is lower (6,000 and 3,300 residents, respectively). Conclusions are that CHC is a major factor that should be accounted for flood resilience and that water management interventions can mitigate risks to human life and activities.

Cost-effective adaptation strategies to rising river flood risk in Europe

River flood risk in Europe could rise to unprecedented levels due to global warming and continued development in flood-prone areas. Here, we appraise the potential of four key adaptation strategies to reduce flood risk across Europe based on flood risk modelling and cost–benefit analysis. We find that reducing flood peaks using detention areas is economically the most attractive option. In a scenario without climate mitigation (3 °C global warming), they can lower projected flood losses in Europe by 2100 from €44(30–61) billion to €8.1(5.5–10.7) billion per year and lower population exposed by 84% (75–90%) or achieve a risk level comparable to today. The economic investment required over 2020–2100 would provide a return of €4(3.5–6.3) for each €1 invested. The risk reduction potential of strengthening of dykes is somewhat lower, at 70% (59–83%) for a comparable annual investment. Implementing building-based flood proofing and relocation measures is less cost-effective but can reduce impacts in localized areas.

Towards flood risk reduction: Commonalities and differences between urban flood resilience and risk based on a case study in the Pearl River Delta

Despite traditional measures to prevent disasters, climate change and urbanization increase flood risk. Thus, flood resilience has attracted increased global concern. Understanding the commonalities and differences between flood resilience and risk is arguably important for flood risk reduction. However, these factors have been seldom reported in previous studies, and discussions on the role of flood resilience in flood risk analysis, assessment, and management are lacking. In this study, the association between flood resilience and risk is discussed using a case study in the Pearl River Delta. Flood resilience is quantified using a pressure-state-response (PSR) model, while flood risk is assessed based on the hazard-vulnerability framework and the extension catastrophe progression method. The implications of considering flood resilience in flood risk analysis, assessment, and management are proposed. The results suggest that the overall flood resilience (risk) in the study area is greater (lower) than that in the highly urbanized areas, and areas with low (high) flood resilience (risk) are mainly concentrated within the highly urbanized areas. Indices extracted from human society and highly related to human activities have the same attributes in both frameworks, while indices associated with climate and geography contribute to the two concepts differently. Flood resilience supplements the concept of flood risk, and can be incorporated into risk assessment as an index. Moreover, pre-disruption (post-disaster) measures should follow flood risk (resilience) assessment, and strategies that foster flood resilience should be included in flood risk management. This study provides references for flood resilience improvement and risk mitigation.