Flash flood risk management in Malloa (Central Chile) during the 29-31 January 2021 precipitations: insights on social and institutional vulnerabilities
Abstract as pdf
Corresponding Author:
Francisca Vergara-Pinto
Centro de Estudios del Desarrollo Regional y Políticas Públicas, Universidad de Los Lagos Chile
franverggara@gmail.com
Author(s):
Jorge Romero1
1School Of The Earth And Environmental Sciences, The University Of Manchester, Jorge.Romero@Postgrad.Manchester.Ac.Uk, GBR
Flash flood hazard and risk management in Chile is still reactive. In the context of climate change, the distribution of areas exposed to extreme precipitation events has changed, now including areas previously characterized by low return periods. In this sense, flood risk assessment and management requires the integration of the scientific knowledge to the institutional disaster governance at communal and regional scales; it requires the generation of detailed susceptibility, hazard and risk maps developed by both Earth and social sciences professionals with the goal of better understanding multidimensional flood risk (Cruden, 1991; Oliver-Smith, 2016). This is especially relevant when the exposed communities comprise lowincome rural areas with absolute lack of historic experience to cope with flood hazard, thus increasing the vulnerability of local institutions to successfully respond and recover from the emergency. We investigated the 29 and 31 January 2021 extreme rainfall event which affected central Chile, producing catastrophic flash floods in both the Andean and Coastal Mountains. This event represents a rare case of torrential hail and rainfall storm during the southern hemisphere summer affecting an extensive segment of central Chile. Our study focuses on the small commune of Malloa, which has been not previously affected by historic flood events, however during the storm experienced severe impacts of flash floods, including 200 injured and 73 damaged houses. In order to assess the stakeholder decision making process, we carried out a detailed mapping of the local geology and geomorphology, plus a comprehensive mapping of the 29-31 January deposits and impacts. In parallel, the study involved the sociocultural analysis of vulnerability to floods, with special focus on the disaster experience of the local community. Along this process, we also discovered several institutional factors increasing risk, such as: 1) lack of experience related to flood risk management; 2) limited response due to limited resources; 3) complex interinstitutional networks for decision-making; 4) political factors playing a role in the response and 5) long-term territorial planning restricted by existing law framework. Our study involved roundtable exercises with the direct participation of the community, stakeholders and institutional authorities, concluding with several recommendations for flood risk prevention, mitigation and capacity building at community and institutional levels.
Cruden, D.M., Varnes, D.J. (1996). Landslide types and processes. In: Turner AK, Schuster RL(eds) Landslides investigation and mitigation. Transportation research board, US.
Oliver-Smith, A. (2016). Disaster risk reduction and applied anthropology. Annals of Anthropological Practice 40 (1): 73-85.
Institutional settings in flood hazard and risk management