Mapping direct flood impacts from a 2020 extreme flood event in central Vietnam using spatial analysis techniques

Purpose: In October 2020, Vietnam was repeatedly hit by large storms, including Linfa, Nangka, Saudel and Molave, causing heavy rains and whirlwinds in the Central provinces of Vietnam. The heavy rain led to severe flooding in many localities. The water levels on major rivers broke records of historical flood events in 1950, 1979, 1999, 2007, 2010 and 2016. In response, this paper aims to quantify the impacts of 2020 flooding to support flood risk management activities and the relief agencies that can use the analysis. Design/methodology/approach: This study demonstrates an approach to quickly map flood impacts on population, schools, health-care facilities, agriculture, transportation and business facilities and assess flood risks using available data and spatial analysis techniques. Findings: The results show that all districts of Quang Binh were affected by the event, in which 1,014 residential areas, 70 schools, 13 health-care facilities, 32,558 ha of agriculture lands, 402 km road length, 29 km railway, 35 bridges on roads and 239 business facilities were exposed within flooded areas. Research limitations/implications: This study is limited to direct or tangible impacts, including flooded residential areas, schools, health-care facilities, agriculture land categories, road networks and business facilities. Indirect or intangible impacts such as health, flood pollution and business disruption should be considered in further studies. Practical implications: These detailed impact maps can support decision-makers and local authorities in implementing recovery activities, allocating relief and devoting human resources and developing flood risk management action plans and land-use planning in the future. Social implications: This study investigates the context of flood impacts on population, schools, health-care facilities, agriculture, transportation and business facilities. Based on this research, decision-makers can better understand how to support affected communities and target the most at risk people with interventions. Originality/value: This paper presents a framework to quantify the impacts of the 2020 extreme flood event using available data and spatial analysis techniques in support of flood risk management activities.