Geography Reference
In-Depth Information
to bloom'. This is shown in Figure 17, where the circular
productive areas produced by sprinklers from rotating pipelines
contrast dramatically with the surrounding barren landscape.
The downside of this admirable achievement is often the
long-term depletion of the groundwater reserves at a faster
rate than natural recharge of the aquifers from rain falling on
the surrounding regions. This may require water rationing.
Furthermore, salinization often results in reduced productivity
and eventual desertifi cation caused by the accumulation of salts
following the evaporation of water from the soil. The United
Nations Food and Agriculture Organization has estimated that
125,000 hectares of land are lost worldwide each year through
salinization.
The vulnerability of people to natural hazards provides a second
illustration of effects of the environment on people. Natural
hazards are extreme natural events that pose a risk to human
systems. They include meteorological, geological, and biological
events, but human-caused pollution hazards and diseases that
threaten human health are normally excluded. Severe impacts of
geophysical hazards - such as earthquakes, volcanic eruptions,
fl oods, and tropical cyclones - commonly have disastrous
consequences for society. But the same level of hazardousness can
have widely differing impacts in different societies with different
vulnerabilities. In an average year, some 250,000 people die from
natural hazards, more than 80% of these in developing countries.
Recent examples were provided by the Boxing Day tsunami
of 2004, which affected populations around the shores of the
Indian Ocean, and the Kashmir earthquake in Pakistan in 2005.
In contrast, economic costs in terms of damage to property and
interruption to businesses tend to be highest in the developed
world, belying the false notions that technologically advanced
societies are the least vulnerable and that they are less vulnerable
today than in the past. This was graphically demonstrated both
by the inundation of New Orleans following Hurricane Katrina
in 2005 and by the river fl oods in southern England caused by
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