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Other disasters

Environmental degradation and change are becoming increasingly important in relation to both the occurrence and impact of natural disasters. Deforestation, for example, is now frequently linked to severe flood events and landslides. Overexploitation of water resources has already resulted in sub-regional environmental disasters such as the drying up of the Aral Sea in Central Asia (see box below and feature).

The Aral Sea: a human-induced environmental and humanitarian disaster

The destruction of the Aral Sea is now a wellknown example of unsustainable development. Atlases used to describe the sea as the world's fourth largest lake, with an area of 66 000 km2 and a volume of more than 1 000 km3. Its waters supplied local fisheries with annual catches of 40 000 tonnes, while the deltas of its tributaries hosted dozens of smaller lakes and biologically rich marshes and wetlands covering 550 000 ha.

In the 1960s, planners in the former Soviet Union assigned Central Asia the role of supplier of raw cotton. Irrigation was imperative, and the Aral Sea and its tributaries seemed a limitless source of water. Irrigated land was expanded from about 4.5 million ha in 1960 to almost 7 million ha in 1980. The local population also grew rapidly, from 14 million to about 27 million in the same period, while total water withdrawal almost doubled to an annual 120 km3, more than 90 per cent of it for agriculture.

The result was the collapse of the prevailing water balance in the basin. Waterlogging and salinization eventually affected about 40 per cent of irrigated land. Overuse of pesticides and fertilizer polluted surface water and groundwater, and the delta ecosystems simply perished: by 1990, more than 95 per cent of the marshes and wetlands had given way to sand deserts, and more than 50 delta lakes, covering 60 000 ha, had dried up.

The surface of the Aral Sea shrank by one-half and its volume by three-quarters. The mineral content of the water has increased fourfold, preventing the survival of most of the sea's fish and wildlife. Commercial fishing ended in 1982. Former seashore villages and towns are now 70 km from the present shoreline.

Communities face appalling health problems. In Karakalpakstan, Uzbekistan, drinking water is saline and polluted, with a high content of metals that causes a range of diseases. Over the past 15 years, there has been a 3 000 per cent increase in chronic bronchitis and in kidney and liver diseases, especially cancer, while arthritic diseases have increased 6 000 per cent. The infant mortality rate is one of the world's highest.

Five newly independent Central Asian states have now established a joint commission for water coordination. Several international organizations and bilateral agencies are providing assistance, and an International Fund for the Aral Sea and the Interstate Council for the Aral Sea Problem have been set up to coordinate initiatives.

The Central Asian republics have decided to focus on demand management, aiming to reduce water withdrawal by raising irrigation efficiency. The primary objective is to satisfy crop water requirements. Total water withdrawal in the basin has now stabilized at 110-120 km3/year but environmental degradation continues.

Source: FAO 1998

Most of the countries in the Northwest Pacific and East Asia sub-region and the Pacific Island countries will be particularly vulnerable to climate change and associated sea-level rise because so many human settlements and so much industrial infrastructure are located in coastal or lowland areas. For the small island developing states, climate change and extreme weather events may also have dramatic impacts on terrestrial biodiversity, subsistence cropping and forest food sources (IPCC 1998).

Rapid population growth, urbanization and weak land-use planning are some of the reasons why poor people move to fragile and high risk areas which are more exposed to natural hazards. Moreover, the rapid growth of industries in urban areas has induced rural-urban migration. This has sometimes led to more people being exposed to technological hazards such as the disaster in Bhopal, India, in 1984, in which escaping methyl isocyanate from an industrial plant killed more than 3 000 and affected more than 200 000 others (Robins 1990).