Chapter 12 Urban Flood Risk Communication for Cities

The fact that the world is becoming increasingly urbanized is recognized by the United Nations (UNFPA, 2007) in the State of the World Population Report as the “The Urban Millennium.” In year 1950, 30% of the world's population lived in cities and as of recently, the population has reached up to 50%, making year 2007 a turning point in the history of urban population growth (Bigio, 2003; Kreimer, Arnold, & Caitlin, 2003; UN-HABITAT, 2007). By year 2030, the United Nations expects more than 60% of population to be living in cities (Munich Re, 2005). And as shown by Surjan and Shaw (2009), by year 2050, the world's urban population is expected to grow by 3 billion people. Most of this growth will take place in developing countries, with the urban population in cities and towns doubling. As it has been summarized, from 1991 to 2005, more than 3.5 billion people were affected by disasters; more than 950,000 people have taken their lives unwillingly and damages have reached nearly 1,193 billion US dollars. Developing countries will suffer the most from climate change, since they are disproportionally affected and have intrinsic vulnerabilities to hazards and so far have struggled in increasing the capacity for risk reduction measures (Wahlström, 2009). Nevertheless, by contrast, even in the largest and wealthiest countries, which have diversified economies and risk transfer mechanisms, the loss has topped an amount of billions of US dollars, as was the case with Hurricane Katrina in USA in 2005. It has been confirmed with facts over the last two decades (1988–2007) that 76% of all disaster events were hydrological, meteorological, or climatological in nature, whether it occurred in urban or in rural areas.