Flood risk assessment using GIS-based Multicriteria analysis in River Nyamwamba catchment, Kasese

Abstract

Globally, floods are the costliest natural hazard in the world and account for a 31percent of economic losses resulting from natural catastrophes. Especially, river flooding has been a major natural hazard worldwide in recent events, e.g., in Cleveland in 2006, Bolivia in January 2007, Namibia in February 2007, Australia in March 2007, millions of people were affected in socio-economic life, thousands of people died and it caused the physical loss of over 20 billion USA Dollars (United Nations and European Commission Report 2007). Determining the floodvulnerable areas is important for decision-makers for planning and management activities (Yahaya, Ahmad & Abdalla, 2010). Higher levels of vulnerability to extreme events, especially floods, are becoming a “new normal” in both developing and developed countries (Mirza, 2003; Thomalla et al., 2006). Floods are among the most devastating natural hazards in the world, claiming more lives and causing more property damage than any other natural phenomenon (Duan et al. 2014). According to the Intergovernmental Panel on climate change (IPCC), it is projected that there will be higher frequencies and intensities of floods and drought in Africa as a consequence of climate change (IPCC, 2007). The impact of flooding is especially harmful in developing countries due to low levels of flood protection. For example, 6,648 flood fatalities were recorded in 2013 in India and Nepal, while the Philippines suffered from recurring flooding that caused more than 100 fatalities every year between 2011 and 2013, and prolonged flooding in Thailand in 2011 caused serious economic losses (EM-DAT, 2016).