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Urbanization and disaster

"International Sabo Symposium 2015 in Sendai" is held on 18 March 2015 as a public forum of the 3rd World Conference on DRR. Under the theme of "Challenges to increasing risk of sediment disasters due to poorly managed urban development on steep slopes and climate change (provisional)", the symposium will address issues: urbanization and disaster, climate change and disaster, disaster statistics, information sharing etc.

This message refers to "urbanization and disaster". I have been collecting information relevant to this issue to prepare for the Symposium, some of which I would like to share with ISN members as follows:

1. Global population growth, urbanization and settlements in hazard prone areas

World population is growing rapidly, nearly four times during a century (1950-2050), while urban population is growing more rapidly, more than eight times during the same period. World population growth is substantially due to the increase in urban population of developing countries. (Table1, Figures 1-4(PDF: 141KB))

Urban population growth is mainly due to influx of people from rural areas. They live in informal settlements, many of which are in hazard prone locations such as hillside slopes prone to landslides and areas along torrents prone to debris flows as well as low-lying areas prone to flooding. The population in informal settlements is increasing surprisingly by 25 million per year. (2009 UN Global Assessment Report on DRR)

Even in developed countries, urbanization has been taking place along with industrialization, which is too rapid for land-use management and other DRR measures of government to keep up with, resulting in disasters as Japan has been experiencing in newly urbanized areas.

Examples of major cities with large urban areas on hazardous slopes include Caracas/Venezuela, La Paz/Bolivia, Bogota/Colombia, Guatemala/Guatemala etc.; Those which recently experienced sediment disasters in urbanized areas include Hiroshima/Japan(2014), Seoul/Korea(2011), Rio de Janeiro/Brazil(2011) etc. (Photo1, 2(PDF: 195KB))

2. Challenges to reduce risk of sediment disasters in areas developed on slopes of urban periphery

Today, more than half of the world population lives in urban areas, and more and more people are moving from rural to urban areas to settle in potential danger zones forming informal societies. Due to this alarming fact, the 3rd WCDRR will address "urbanization and disaster" as an important global DRR issue. In view of the complex nature of legal, social and economic conditions of such informal settlements, the conference will address this issue through wide range of approaches.

As for the Symposium, it will address sediment disaster risk reduction which is a specific but important part of the global DRR, and will cover various DRR measures including physical measures, early warning/evacuation and even slum relocation/upgrading etc. Among them, one of areas of focus will be land-use planning based on risk assessment and its enforcement by by-laws under complex conditions of target areas most of which are informal settlements, as suggested by Post-2015 FDRR (draft), SDGs (draft) (Ref.box(PDF: 131KB))and others.

I hope this information will be useful for ISN members in the discussion on post-2015 FDRR and SDGs at the national platform and other occasions in respective countries and at the Symposium in Sendai.
Looking forward to seeing you soon in March in Sendai,

February 2015

Hidetomi Oi

President of International Sabo Association