Flood risk dynamics and adaptation analyses for coastal cities based on internet big data and hydrology-hydrodynamic models

Abstract. Coastal cities are particularly vulnerable to flood under multivariable conditions, such as heavy precipitation, high sea levels, and storms. The combined effect of multiple sources and the joint probability of extremes should be considered to assess and manage flood risk better. This paper aims to study the combined effect of rainfall and the tidal level of the receiving water body on flood probability and severity in Fuzhou City, which has a complex river network. Flood severity under a range of precipitation intensities, with return periods (RPs) of 5 yr to 100 yr, and tidal levels was assessed through a hydrodynamic model verified by data observed during Typhoon Longwang in 2005. According to the percentages of the river network where flooding occurred, the threshold conditions for flood severity were estimated in two scenarios: with and without working pumps. In Fuzhou City, working pumps efficiently reduce flood risk from precipitation within a 20-yr RP. However, the pumps may not work efficiently when rainfall exceeds a 100-yr RP because of the limited conveyance capacity of the river network. Joint risk probability was estimated through the optimal copula. The joint probability of rainfall and tidal level both exceeding their threshold values is very low, and the greatest threat in Fuzhou comes from heavy rainfall. However, the tidal level poses an extra risk of flood. Given that this extra risk is ignored in the design of flood defense in Fuzhou, flood frequency and severity may be higher than understood during design.

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METHODOLOGICAL CHALLENGES AND STRATEGIESTO INCORPORATE CLIMATE CHANGE INTO FLOOD RISK ANALYSIS OF SPANISH COASTAL CITIES

10.3850/38wc092019-0669 ◽

2019 ◽

Author(s):

MARÍA BERMÚDEZ ◽

LUIS CEA ◽

MIGUEL A. LOSADA ◽

JERÓNIMO PUERTAS ◽

MIGUEL ORTEGA- SÁNCHEZ

Keyword(s):

Climate Change ◽

Risk Analysis ◽

Flood Risk ◽

Coastal Cities ◽

Methodological Challenges ◽

Flood Risk Analysis

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Assessment of the effectiveness of flood adaptation strategies for HCMC

Natural Hazards and Earth System Science ◽

10.5194/nhess-14-1441-2014 ◽

2014 ◽

Vol 14 (6) ◽

pp. 1441-1457 ◽

Cited By ~ 26

Author(s):

R. Lasage ◽

T. I. E. Veldkamp ◽

H. de Moel ◽

T. C. Van ◽

H. L. Phi ◽

...

Keyword(s):

Sea Level ◽

Flood Risk ◽

Net Present Value ◽

Adaptation Strategies ◽

Ho Chi Minh City ◽

Cost Ratio ◽

Present Value ◽

Benefit Cost Ratio ◽

Coastal Cities ◽

Benefit Cost

Abstract. Coastal cities are vulnerable to flooding, and flood risk to coastal cities will increase due to sea-level rise. Moreover, Asian cities in particular are subject to considerable population growth and associated urban developments, increasing this risk even more. Empirical data on vulnerability and the cost and benefits of flood risk reduction measures are therefore paramount for sustainable development of these cities. This paper presents an approach to explore the impacts of sea-level rise and socio-economic developments on flood risk for the flood-prone District 4 in Ho Chi Minh City, Vietnam, and to develop and evaluate the effects of different adaptation strategies (new levees, dry- and wet proofing of buildings and elevating roads and buildings). A flood damage model was developed to simulate current and future flood risk using the results from a household survey to establish stage–damage curves for residential buildings. The model has been used to assess the effects of several participatory developed adaptation strategies to reduce flood risk, expressed in expected annual damage (EAD). Adaptation strategies were evaluated assuming combinations of both sea-level scenarios and land-use scenarios. Together with information on costs of these strategies, we calculated the benefit–cost ratio and net present value for the adaptation strategies until 2100, taking into account depreciation rates of 2.5% and 5%. The results of this modelling study indicate that the current flood risk in District 4 is USD 0.31 million per year, increasing up to USD 0.78 million per year in 2100. The net present value and benefit–cost ratios using a discount rate of 5 % range from USD −107 to −1.5 million, and from 0.086 to 0.796 for the different strategies. Using a discount rate of 2.5% leads to an increase in both net present value and benefit–cost ratio. The adaptation strategies wet-proofing and dry-proofing generate the best results using these economic indicators. The information on different strategies will be used by the government of Ho Chi Minh City to determine a new flood protection strategy. Future research should focus on gathering empirical data right after a flood on the occurring damage, as this appears to be the most uncertain factor in the risk assessment.

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Socio-hydrological modelling of flood-risk dynamics: comparing the resilience of green and technological systems

Hydrological Sciences Journal ◽

10.1080/02626667.2016.1273527 ◽

2017 ◽

Vol 62 (6) ◽

pp. 880-891 ◽

Cited By ~ 38

Author(s):

Alessio Ciullo ◽

Alberto Viglione ◽

Attilio Castellarin ◽

Massimiliano Crisci ◽

Giuliano Di Baldassarre

Keyword(s):

Flood Risk ◽

Hydrological Modelling ◽

Technological Systems ◽

Risk Dynamics

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Big Data Approaches for coastal flood risk assessment and emergency response

Wiley Interdisciplinary Reviews Climate Change ◽

10.1002/wcc.543 ◽

2018 ◽

Vol 9 (5) ◽

pp. e543 ◽

Cited By ~ 5

Author(s):

James A Pollard ◽

Tom Spencer ◽

Simon Jude

Keyword(s):

Risk Assessment ◽

Big Data ◽

Emergency Response ◽

Flood Risk ◽

Flood Risk Assessment ◽

Coastal Flood ◽

Coastal Flood Risk

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Rapid flood risk screening model for compound flood events in Beira, Mozambique

10.5194/nhess-2020-56 ◽

2020 ◽

Author(s):

Erik C. van Berchum ◽

Mathijs van Ledden ◽

Jos S. Timmermans ◽

Jan H. Kwakkel ◽

Sebastiaan N. Jonkman

Keyword(s):

Risk Management ◽

Flood Risk ◽

Simulation Models ◽

Flood Risk Management ◽

Coastal Protection ◽

Flood Simulation ◽

High Exposure ◽

Screening Model ◽

Coastal Cities ◽

The Impact

Abstract. Coastal cities combine intensive socio-economic activity and investments with high exposure to flood hazards. Developing effective strategies to manage flood risk in coastal cities is often a costly and complicated process. In the design of these strategies, engineers rely on computationally demanding flood simulation models and only compare a few strategies due to computational constraints. This limits the efficacy of standard flood simulation models in the crucial conceptual phase of flood risk management. This paper presents the Flood Risk Reduction Evaluation and Screening (FLORES)-model, which specifically aims to provide useful risk information early on in the planning process. FLORES performs numerous quick simulations and compares the impact of many storms, strategies, and future scenarios. This article presents the screening model and demonstrates its merits in a case study for Beira, Mozambique. Our results demonstrate that expansion of the drainage capacity and strengthening of its coastal protection in the southwest, are crucial components of any effective flood risk management strategy for Beira.

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