ASSESSMENT OF SOCIAL VULNERABILITY TO FLOOD RISK IN THE NIGER DELTA, NIGERIA

2019 ◽  
pp. 68-73
Keyword(s):  
Flood Risk ◽  
Social Vulnerability ◽  
Niger Delta

scholarly journals Coastal Flooding Risk Assessment Using a GIS-Based Spatial Multi-Criteria Decision Analysis Approach

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2379
Author(s):  
Vahid Hadipour ◽  
Freydoon Vafaie ◽  
Kaveh Deilami
Keyword(s):  
Risk Assessment ◽  
High Risk ◽  
Decision Analysis ◽  
Sea Level ◽  
Flood Risk ◽  
Social Vulnerability ◽  
Quantitative Methods ◽  
Coastal Flooding ◽  
Rcp Scenarios ◽  
Multi Criteria Decision Analysis

Coastal areas are expected to be at a higher risk of flooding when climate change-induced sea-level rise (SLR) is combined with episodic rises in sea level. Flood susceptibility mapping (FSM), mostly based on statistical and machine learning methods, has been widely employed to mitigate flood risk; however, they neglect exposure and vulnerability assessment as the key components of flood risk. Flood risk assessment is often conducted by quantitative methods (e.g., probabilistic). Such assessment uses analytical and empirical techniques to construct the physical vulnerability curves of elements at risk, but the role of people’s capacity, depending on social vulnerability, remains limited. To address this gap, this study developed a semiquantitative method, based on the spatial multi-criteria decision analysis (SMCDA). The model combines two representative concentration pathway (RCP) scenarios: RCP 2.6 and RCP 8.5, and factors triggering coastal flooding in Bandar Abbas, Iran. It also employs an analytical hierarchy process (AHP) model to weight indicators of hazard, exposure, and social vulnerability components. Under the most extreme flooding scenario, 14.8% of flooded areas were identified as high and very high risk, mostly located in eastern, western, and partly in the middle of the City. The results of this study can be employed by decision-makers to apply appropriate risk reduction strategies in high-risk flooding zones.

Evaluation of flood risk drivers as a tool to define municipal risk profiles

2020 ◽  
Author(s):  
Pedro Pinto Santos ◽  
Susana Pereira ◽  
José Luís Zêzere ◽  
Alexandre Oliveira Tavares ◽  
Eusébio Reis ◽  
...  
Keyword(s):  
Risk Management ◽  
Flood Risk ◽  
Social Vulnerability ◽  
Methodological Approach ◽  
Risk Index ◽  
Slope Angle ◽  
Road Density ◽  
High Exposure ◽  
Hazard Exposure ◽  
Flood Susceptibility

<p>This work aims to compute a flood risk index (FRI) for the 278 Portuguese municipalities, designed to rank and characterize the drivers of fluvial flooding-related disasters (Santos et al., 2020). FRI is the product of hazard, exposure and vulnerability scores, where each factor is raised to 1/3, a solution also applied by the INFORM risk index to increase the dispersion of index values.</p><p>Hazard considers two variables: flood susceptibility (SUSCF), and the weather and climate events index (WCE) translating the frequency of the rainfall events that may generate peak flows. SUSCF is the product of stream flood susceptibility (SFS) (Santos et al., 2019) and the main flood-prone areas (MFPA). SFS considers flow accumulation, slope angle and relative permeability, accounting for the cumulative effect of these factors along the entire basins’ area. MPFA results from overlaying areas with slope angle ≤ 2º and areas with Height Above Nearest Drainage ≤ 2, only when they were topologically connected to streams with SFS > 5.</p><p>Exposure considers three variables: population density (PD), road density (RD) and the average degree of imperviousness (ADI). PD (inhab./km<sup>2</sup>) is based on the 2011 Census. RD (km/km<sup>2</sup>) is calculated from the OpenStreetMap<sup>©</sup> data. ADI is the municipal average value of the layer “IMD - Imperviousness Degree 2012 – 20 m resolution”, from the Copernicus Land Monitoring Service.</p><p>Vulnerability (V) is the product of criticality and support capability, where the latter acts by attenuating criticality, according to the methodology presented by Tavares et al. (2018) to assess social vulnerability.</p><p>The six core variables were scaled to the range [0, 1] following the max-min method. The respective weights were tested and selected according to the scientific literature, correlation and reliability tests.</p><p>Ward’s clustering classification was used to define seven clusters of municipalities, differing in the scores of hazard, exposure and vulnerability. While it is suggested that municipalities in some clusters would require interventions to reduce hazard, others should invest on medium to long-term measures that address high exposure and vulnerability. The results obtained with this methodological approach contribute to the diversification of flood risk management strategies.</p><p> </p><p>Acknowledgements:</p><p>This work was financed by national funds through FCT—Portuguese Foundation for Science and Technology, I.P., under the framework of the project BeSafeSlide‑Landslide Early Warning soft technology prototype to improve community resilience and adaptation to environmental change (PTDC/GES-AMB/30052/2017) and by the Research Unit UIDB/00295/2020. Pedro Pinto Santos is funded by FCT through the project with the reference CEEIND/00268/2017.</p><p> </p><p>References:</p><p>Santos, P.P., Pereira, S., Zêzere, J.L., Tavares, A.O., Reis, E., Garcia, R.A.C., Oliveira, S.C., 2019. A comprehensive approach to understanding flood risk drivers at the municipal level. J. Environ. Manage. https://doi.org/10.1016/j.jenvman.2020.110127</p><p>Santos, P.P., Reis, E., Pereira, S., Santos, M., 2019. A flood susceptibility model at the national scale based on multicriteria analysis. Sci. Total Environ. 667, 325–337. https://doi.org/10.1016/j.scitotenv.2019.02.328</p><p>Tavares, A.O., Barros, J.L., Mendes, J.M., Santos, P.P., Pereira, S., 2018. Decennial comparison of changes in social vulnerability: A municipal analysis in support of risk management. Int. J. Disaster Risk Reduct. 31, 679–690. https://doi.org/10.1016/J.IJDRR.2018.07.009</p>

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

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.

scholarly journals Flood Risk Assessment of Communities to Flood Hazards in Central Niger Delta, Nigeria

2021 ◽  
Vol 4 (1) ◽  
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
Disaster Preparedness ◽  
Niger Delta ◽  
Sampling Technique ◽  
Flood Hazards ◽  
River Channels ◽  
Social Infrastructure ◽  
Entire Study ◽  
Flood Exposure

The study examined the risk assessment of communities in the Central Niger Delta, Nigeria with a view to employing analytical hierarchical ranking process technique. The study considered the landuse, elevation, soil texture and proximity to active river channels as factors determining flood vulnerability (FV) while factors such as accessibility, social infrastructure, water supply, agriculture, commercial activities and disaster preparedness of communities were used for flood exposure (FE) using purposive sampling technique. Both FV and FE were combined together using UNION Module of ArcGIS 10.5 to produce flood risk map of the Central Niger Delta. Descriptive statistics using frequency and percentages were used for the data analysis. Findings revealed that 20.25%, 51.66% and 28.09% of the entire study area were lowly vulnerable, moderately vulnerable and highly vulnerable to flood. Similarly, 0.3%, 45.7% and 54.8% were lowly exposed, moderately exposed and highly exposed to flood. However, 14.3%, 28.3% and 57.4% of the study area had low flood risk, moderate flood risk and high flood risk respectively. The study concluded that majority of the area in the Central Niger Delta is risky to flood. It is recommended among others that channelization and dredging of River Niger Creeks in the study area are important in order for the river to accommodate more volume of water whenever there is excessive rainfall.

scholarly journals Social Vulnerability Assessment for Flood Risk Analysis

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 558 ◽  
Author(s):  
Laura Tascón-González ◽  
Montserrat Ferrer-Julià ◽  
Maurici Ruiz ◽  
Eduardo García-Meléndez
Keyword(s):  
Vulnerability Assessment ◽  
Flood Risk ◽  
Social Vulnerability ◽  
Large Scale ◽  
Vulnerability Index ◽  
Social Vulnerability Index ◽  
Coping Capacity ◽  
High Exposure ◽  
Public Data ◽  
Social Vulnerability Assessment

This paper proposes a methodology for the analysis of social vulnerability to floods based on the integration and weighting of a range of exposure and resistance (coping capacity) indicators. It focuses on the selection and characteristics of each proposed indicator and the integration procedure based on the analytic hierarchy process (AHP) on a large scale. The majority of data used for the calculation of the indicators comes from open public data sources, which allows the replicability of the method in any area where the same data are available. To demonstrate the feasibility of the method, a study case is presented. The flood social vulnerability assessment focuses on the municipality of Ponferrada (Spain), a medium-sized town that has high exposure to floods due to potential breakage of the dam located upstream. A detailed mapping of the social vulnerability index is generated at the urban parcel scale, which shows an affected population of 34,941 inhabitants. The capability of working with such detailed units of analysis for an entire medium-sized town provides a valuable tool to support flood risk planning and management.

Integrating social vulnerability into federal flood risk management planning

2013 ◽  
Vol 6 (4) ◽  
pp. 332-344 ◽  
Author(s):  
S.L. Cutter ◽  
C.T. Emrich ◽  
D.P. Morath ◽  
C.M. Dunning
Keyword(s):  
Risk Management ◽  
Flood Risk ◽  
Social Vulnerability ◽  
Flood Risk Management ◽  
Management Planning ◽  
Risk Management Planning

Vulnerability Assessment during Mass Evacuation: Integrated Microsimulation-Based Evacuation Modeling Approach

2019 ◽  
Vol 2673 (10) ◽  
pp. 225-238
Author(s):  
MD Jahedul Alam ◽  
Muhammad Ahsanul Habib
Keyword(s):  
Vulnerability Assessment ◽  
Flood Risk ◽  
Social Vulnerability ◽  
Large Scale ◽  
Risk Model ◽  
Life Stage ◽  
Urban Systems ◽  
Modeling Approach ◽  
Systems Model

This study develops an integrated microsimulation-based evacuation model that performs a vulnerability assessment of the Halifax Peninsula, Canada during an evacuation. The proposed framework of vulnerability assessment accounts for long-term changes in neighborhood composition in relation to socio-demographic characteristics, residential locations, and vehicle ownership. The results of a large-scale urban systems model and a flood risk model are used to inform the vulnerability assessment. The urban systems model encapsulates long-term household decisions and life stage transitions in measuring social vulnerability. The flood risk model provides information on flood severity and finer network disruptions. In addition, a dynamic traffic assignment-based microsimulation model is developed to assess mobility vulnerability during an evacuation. One of the key contributions of this study is that it utilizes a Bayesian Belief Network modeling approach for vulnerability assessment, while addressing uncertainty and causal relationships between different elements of vulnerability. The results suggest that the Peninsula zones are at a relatively higher risk from a mobility point of view. A sensitivity analysis reveals that clearance time has been found to be the key determinant of the mobility vulnerability during an evacuation. “Presence of female” and “presence of seniors” are found as the two most significant contributors of social vulnerability. Several peripheral zones are at a higher risk because of their proximity to the flood source. The proposed research will help emergency professionals and engineers to develop effective evacuation plans in relation to vulnerable areas.

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