FLOOD RISK EVALUATION OF CLASS A RIVER SYSTEMS USING RISK CURVES BASED ON FLOOD DISASTER STATISTICS

Abstract. To manage flood disaster with an exceeding designed level, flood risk control based on appropriate risk assessment is essential. To make an integrated economic risk assessment by flood disaster, a flood risk curve, which is a relation between flood inundation damage and its exceedance probability, plays an important role. This research purposes a method to develop a flood risk curve by utilizing a probability distribution function of annual maximum rainfall through rainfall-runoff and inundation simulations so that risk assessment can consider climate and socio-economic changes. Among a variety of uncertainties, the method proposed in this study considered spatio-temporal rainfall distributions that have high uncertainty for damage estimation. The method was applied to the Yura-gawa river basin (1882 km2) in Japan; and the annual economic benefit of an existing dam in the basin was successfully quantified by comparing flood risk curves with/without the dam.

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A Case Study of Flood Risk Evaluation Based on Emergy Theory and Cloud Model in Anyang Region, China

Water ◽

10.3390/w13040420 ◽

2021 ◽

Vol 13 (4) ◽

pp. 420

Author(s):

Zening Wu ◽

Yuhai Cui ◽

Yuan Guo

Keyword(s):

Risk Assessment ◽

Flood Risk ◽

Flood Control ◽

Flood Hazard ◽

Cloud Model ◽

Flood Disaster ◽

Assessment System ◽

Assessment Model ◽

Flood Risk Assessment ◽

Emergy Theory

With the progression of climate change, the intensity and frequency of extreme rainfall have increased in many parts of the world, while the continuous acceleration of urbanization has made cities more vulnerable to floods. In order to effectively estimate and assess the risks brought by flood disasters, this paper proposes a regional flood disaster risk assessment model combining emergy theory and the cloud model. The emergy theory can measure many kinds of hazardous factor and convert them into unified solar emergy (sej) for quantification. The cloud model can transform the uncertainty in flood risk assessment into certainty in an appropriate way, making the urban flood risk assessment more accurate and effective. In this study, the flood risk assessment model combines the advantages of the two research methods to establish a natural and social dual flood risk assessment system. Based on this, the risk assessment system of the flood hazard cloud model is established. This model was used in a flood disaster risk assessment, and the risk level was divided into five levels: very low risk, low risk, medium risk, high risk, and very high risk. Flood hazard risk results were obtained by using the entropy weight method and fuzzy transformation method. As an example for the application of this model, this paper focuses on the Anyang region which has a typical continental monsoon climate. The results show that the Anyang region has a serious flood disaster threat. Within this region, Linzhou County and Anyang County have very high levels of risk for flood disaster, while Hua County, Neihuang County, Wenfeng District and Beiguan District have high levels of risk for flood disaster. These areas are the core urban areas and the economic center of local administrative regions, with 70% of the industrial clusters being situated in these regions. Only with the coordinated development of regional flood control planning, economy, and population, and reductions in the uncertainty of existing flood control and drainage facilities can the sustainable, healthy and stable development of the region be maintained.

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Flood Risk Assessment and Application of Risk Curves to Enhance Resilience

10.3850/978-981-18-2016-8_719-cd ◽

2021 ◽

Author(s):

Ning Zhang ◽

Alice Alipour

Keyword(s):

Risk Assessment ◽

Flood Risk ◽

Flood Risk Assessment ◽

Risk Curves

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Flood risk assessment and application of risk curves for design of mitigation strategies

International Journal of Critical Infrastructure Protection ◽

10.1016/j.ijcip.2021.100490 ◽

2021 ◽

pp. 100490

Author(s):

Ning Zhang ◽

Alice Alipour

Keyword(s):

Risk Assessment ◽

Flood Risk ◽

Mitigation Strategies ◽

Flood Risk Assessment ◽

Risk Curves

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Feedback Mechanism in Bifurcating River Systems: the Effect on Water-Level Sensitivity

Water ◽

10.3390/w12071915 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1915

Author(s):

Matthijs R.A. Gensen ◽

Jord J. Warmink ◽

Fredrik Huthoff ◽

Suzanne J.M.H. Hulscher

Keyword(s):

Water Level ◽

Flood Risk ◽

River System ◽

Feedback Mechanism ◽

Water Levels ◽

River Systems ◽

Water Level Variations ◽

System Water ◽

Discharge Distribution ◽

Single Branch

Accurate and reliable estimates of water levels are essential to assess flood risk in river systems. In current practice, uncertainties involved and the sensitivity of water levels to these uncertainties are studied in single-branch rivers, while many rivers in deltas consist of multiple distributaries. In a bifurcating river, a feedback mechanism exists between the downstream water levels and the discharge distribution at the bifurcation. This paper aims to quantify the sensitivity of water levels to main channel roughness in a bifurcating river system. Water levels are modelled for various roughness scenarios under a wide range of discharge conditions using a one-dimensional hydraulic model. The results show that the feedback mechanism reduces the sensitivity of water levels to local changes of roughness in comparison to the single-branch river. However, in the smaller branches of the system, water-level variations induced by the changes in discharge distribution can exceed the water-level variations of the single-branch river. Therefore, water levels throughout the entire system are dominated by the conditions in the largest branch. As the feedback mechanism is important, the river system should be considered as one interconnected system in river maintenance of rivers, flood-risk analyses, and future planning of river engineering works.

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Terrain Hazard Risk Analysis for Flood Disaster Management in Chaohu Basin, China, Based on Two-Dimensional Cloud

Journal of Advanced Computational Intelligence and Intelligent Informatics ◽

10.20965/jaciii.2020.p0532 ◽

2020 ◽

Vol 24 (4) ◽

pp. 532-542

Author(s):

Jun Lyu ◽

Xianfu Cheng ◽

Peter Shaw ◽

◽

Keyword(s):

Risk Evaluation ◽

Qualitative Data ◽

Multivariable Analysis ◽

Evaluation Process ◽

Flood Disaster ◽

Preliminary Evaluation ◽

Terrain Analysis ◽

Two Dimensional ◽

Cloud Models ◽

Model Algorithm

Terrain analysis is essential to flood disaster risk evaluation. It is a complicated evaluation process, involving both quantitative and qualitative data analysis. However, quantitative and qualitative data cannot be put into operation directly. Based on stochastic and fuzzy mathematics, cloud models allow interchange between qualitative and quantitative data, dealing with randomness and ambiguity. Two- or multi-dimensional cloud models can solve the problem of multivariable analysis. This study used absolute elevation and neighborhood elevation standard deviation as main factors. Using the model, it demonstrated the construction of qualitative conditions and risk evaluation clouds and established a set of two-dimensional cloud reasoning rules to calculate the joint certainties with all the grids in reasoning rules. By selecting the highest certainty of cloud reasoning, preliminary evaluation results were obtained. For more accurate results, the model algorithm was improved, and further iterations were performed. The results of two-dimensional cloud reasoning showed better dispersion and precision than traditional methods did. The terrain risk distribution of Chaohu Basin, China, agreed with reality with great detail. A new method regarding the risk assessment of flood disaster was also proposed.

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Flood risk evaluation in urban rivers by means of standard equi-risk lines.

Doboku Gakkai Ronbunshu ◽

10.2208/jscej.1986.369_155 ◽

1986 ◽

pp. 155-164 ◽

Cited By ~ 1

Author(s):

Akira MUROTA ◽

Takeharu ETOH ◽

Masanori NAKANISHI

Keyword(s):

Flood Risk ◽

Risk Evaluation ◽

Urban Rivers

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Transition of alien species communities in Class A river systems of Kyushu Island

Journal of the Japanese Society of Revegetation Technology ◽

10.7211/jjsrt.46.186 ◽

2020 ◽

Vol 46 (1) ◽

pp. 186-189

Author(s):

Yuki TOMOGUCHI ◽

Taizo UCHIDA ◽

Daisuke HAYASAKA

Keyword(s):

Alien Species ◽

River Systems ◽

Class A ◽

Kyushu Island

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A GIS-Based Approach for Flood Risk Zoning by Combining Social Vulnerability and Flood Susceptibility: A Case Study of Nanjing, China

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph182111597 ◽

2021 ◽

Vol 18 (21) ◽

pp. 11597

Author(s):

Yi Chen ◽

Zhicong Ye ◽

Hui Liu ◽

Ruishan Chen ◽

Zhenhuan Liu ◽

...

Keyword(s):

Spatial Pattern ◽

Flood Risk ◽

Social Vulnerability ◽

Flood Hazard ◽

Central City ◽

Flood Disaster ◽

Social Vulnerability Index ◽

Urban Centre ◽

Flood Susceptibility

The identification of vulnerable people and places to flood is crucial for effective disaster risk management. Here, we combine flood hazard and social vulnerability index to capture the potential risk of flood. In this paper, Nanjing was taken as the case study to explore the spatial pattern of social vulnerability towards flood at the community scale by developing an index system. Based on the flood risk results of ArcSWAT, the risk of flood disaster in Nanjing was evaluated. The results show the following. (1) Social vulnerability exhibits a central–peripheral pattern in general, which means that the social vulnerability degree is high in the central city and decreases gradually to the suburbs. (2) The susceptibility to flood disaster has a similar circle-layer pattern that is the highest in the urban centre, lower in the exurban areas, and the lowest in the suburb areas. (3) By using the GIS-based zoning approach, communities are classified into four types by comprehensively considering their flood susceptibility and social vulnerability. The spatial pattern is explained, and policy recommendation for reducing flood risk is provided for each type of community. The research has important reference significance for identifying the spatial pattern of social vulnerability to flood and then formulating targeted adaptation countermeasures.

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