Response time to flood events using a social vulnerability index (ReTSVI)

Abstract

Abstract. Current methods to estimate evacuation time during a natural disaster do not consider the socioeconomic and demographic characteristics of the population. This article develops the Response Time by Social Vulnerability Index (ReTSVI). ReTSVI combines a series of modules that are pieces of information that interact during an evacuation, such as evacuation rate curves, mobilization, inundation models, and social vulnerability indexes, to create an integrated map of the evacuation rate in a given location. We provide an example of the application of ReTSVI in a potential case of a severe flood event in Huaraz, Peru. The results show that during the first 5 min of the evacuation, the population that lives in neighborhoods with a high social vulnerability evacuates 15 % and 22 % fewer people than the blocks with medium and low social vulnerability. These differences gradually decrease over time after the evacuation warning, and social vulnerability becomes less relevant after 30 min. The results of the application example have no statistical significance, which should be considered in a real case of application. Using a methodology such as ReTSVI could make it possible to combine social and physical vulnerability in a qualitative framework for evacuation, although more research is needed to understand the socioeconomic variables that explain the differences in evacuation rate.

Reconstruction of the 1941 GLOF process chain at Lake Palcacocha (Cordillera Blanca, Peru)

“…Therefore, direct references for evaluating the empirical adequacy of the dimension of time in the simulation results are lacking. However, travel times play a crucial role related to the planning and design of (early) warning systems and risk reduction measures (Hofflinger et al, 2019). Comparison of the results of scenarios A and AX ( Fig.…”

“…In the Cordillera Blanca, the local population is highly vulnerable to high-mountain process chains, often induced by GLOFs (Carey, 2005;Hofflinger et al, 2019). In order to mitigate this threat, tens of lakes in the Cordillera Blanca have been remediated through technical measures such as open cuts, artificial dams, or tunnels during the last decades (Oppenheim, 1946;Zapata, 1978;Portocarrero, 1984Carey, 2005;Emmer et al, 2018).…”

Social Vulnerability Assessment for Flood Risk Analysis

“…According to the results, the indicator that shows greater relevance concerning the increase of a society's vulnerability is the evacuation time, which is a novel indicator in this type of study; very few studies have included it to define vulnerability [88]. Its importance is that it establishes a very clear threshold between areas where there is a possibility of social recovery and those in which such recovery is truly difficult.…”

“…The evacuation time is an indicator that measures the relationship between citizens' velocity of displacement and the time of arrival of the flood water. Until now, this indicator has only been used for emergency management, and very few studies have included it to define vulnerability [88]. Its importance is that it establishes a very clear threshold between those areas where there is a possibility of social recovery and those in which such recovery is impossible.…”

Towards integrated assessments of water risks in deglaciating mountain areas: water scarcity and GLOF risk in the Peruvian Andes

“…GLOFs can produce peak discharge up to tens of thousands of m 3 /s (Walder and Costa 1996;Richardson and Reynolds 2000;Hubbard et al 2005;Carrivick and Tweed 2016), and thus represent the extremes of high-flow water hazards. GLOFs are representing an ever-looming risk as their outburst can have multiple different triggers and limited time for warning remains (Hofflinger et al 2019).…”