TY - JOUR
T1 - A comparison of social vulnerability indices specific to flooding in Ecuador
T2 - principal component analysis (PCA) and expert knowledge
AU - Bucherie, Agathe
AU - Hultquist, Carolynne
AU - Adamo, Susana
AU - Neely, Colleen
AU - Ayala, Fernanda
AU - Bazo, Juan
AU - Kruczkiewicz, A.
N1 - Funding Information:
This research was funded by the National Aeronautics and Space Administration , grant number 80NSSC18K0342 .
Funding Information:
This research was funded by the National Aeronautics and Space Administration, grant number 80NSSC18K0342.We thank the Cruz Roja Ecuatoriana (Ecuadorian Red Cross) for the close collaboration in this research, supporting the NASA GEO project ?Towards A Global Flood & Flash Flood Early Warning Early Action System Driven by NASA Earth Observations and Hydrologic Models."
Publisher Copyright:
© 2022 The Authors
PY - 2022/4/15
Y1 - 2022/4/15
N2 - Social vulnerability is a key component of the risk equation alongside the context of the hazard and exposure. Increasingly, social vulnerability indices are used to better understand and predict the consequences of disasters, and support the development of improved disaster management policies. Humanitarian organisations particularly strive to capture social vulnerability in their decision processes relative to prioritisation of actions before disasters occur. This research supports the Ecuadorian Red Cross in generating a flood-specific social vulnerability index to inform flash flood early action at the Parroquia level in Ecuador. This paper compares the results from the two most common approaches used to create composite indices, one using the weighting of variables from disaster experts’ judgments (referred to as Expert method) and the other using PCA analysis, with one or more components. While all outcomes reveal similar trends in areas where most indicators suggest the lowest (urban areas) or highest (the Amazon and northwest coastal regions) social vulnerability, the research shows that the choice of the method matters for assessing the social vulnerability in the rest of the country where there are less pronounced vulnerability signals. In those areas, PCA-driven indices suggest higher relative vulnerability levels than Expert outcomes. Further, in the Andes particularly, the PCA outcomes result in wider distribution than the Expert outcomes, and therefore more heterogeneity in the vulnerability assessment. While divergence in outcomes suggests particular attention with the use of composite indexes for decision making, our results provide support to understand the sensitivity in flood-specific social vulnerability outcomes spatially. To go further we emphasise the importance of using historical flood impact data to evaluate the contribution of each variable in the final social vulnerability scores.
AB - Social vulnerability is a key component of the risk equation alongside the context of the hazard and exposure. Increasingly, social vulnerability indices are used to better understand and predict the consequences of disasters, and support the development of improved disaster management policies. Humanitarian organisations particularly strive to capture social vulnerability in their decision processes relative to prioritisation of actions before disasters occur. This research supports the Ecuadorian Red Cross in generating a flood-specific social vulnerability index to inform flash flood early action at the Parroquia level in Ecuador. This paper compares the results from the two most common approaches used to create composite indices, one using the weighting of variables from disaster experts’ judgments (referred to as Expert method) and the other using PCA analysis, with one or more components. While all outcomes reveal similar trends in areas where most indicators suggest the lowest (urban areas) or highest (the Amazon and northwest coastal regions) social vulnerability, the research shows that the choice of the method matters for assessing the social vulnerability in the rest of the country where there are less pronounced vulnerability signals. In those areas, PCA-driven indices suggest higher relative vulnerability levels than Expert outcomes. Further, in the Andes particularly, the PCA outcomes result in wider distribution than the Expert outcomes, and therefore more heterogeneity in the vulnerability assessment. While divergence in outcomes suggests particular attention with the use of composite indexes for decision making, our results provide support to understand the sensitivity in flood-specific social vulnerability outcomes spatially. To go further we emphasise the importance of using historical flood impact data to evaluate the contribution of each variable in the final social vulnerability scores.
KW - Anticipatory action
KW - Composite indices
KW - Ecuador
KW - Flood resilience
KW - Flood risk
KW - Impact data
KW - Vulnerability indicators
KW - ITC-ISI-JOURNAL-ARTICLE
KW - ITC-HYBRID
U2 - 10.1016/j.ijdrr.2022.102897
DO - 10.1016/j.ijdrr.2022.102897
M3 - Article
AN - SCOPUS:85126531466
SN - 2212-4209
VL - 73
SP - 1
EP - 21
JO - International journal of disaster risk reduction
JF - International journal of disaster risk reduction
M1 - 102897
ER -