Geography Reference
In-Depth Information
providing local authorities with time to organize evacuation from the areas under
risk. However such messages may not reach people on the increasing number of
tourist areas or beaches in underdeveloped lands. This has led to the installation of
sirens to alert people to take precautions and to proceed to emergency refuge loca-
tions, although there is always the problem that visitors may not know these places.
Yet landslides, tornadoes, hail and intense localised rainfall in particular occur with
little warning. Also first world communication systems may not be present in many
remote third world areas. So many governments, often with assistance from agen-
cies such as Oxfam, have been issuing radios to families and to inaccessible local
villages—especially wind-up radios that do not depend on batteries—so that their
recipients have the ability to monitor emergency alerts. Similar advanced warnings
occur in relation to potential hazards for human health, such as by the routine broad-
casts in developed countries about extreme wind-chill conditions, or even UV in-
dexes in summer, a result of information about the increase of skin cancer rates from
overexposure to ultra-violet rays. Also there are finally signs of greater responsibil-
ity by some governments in rapidly industrializing countries to warn people of high
air pollution levels in many large cities. In early 2013 China announced that 74 of its
cities would now begin monitoring and publicizing all sorts of air pollutants, such
as SO
2
, CO
2
, CO and ozone, and also including PM 2.5 (those particulates of under
2.5 μ in size. The latter has been shown to be a particular health hazard since they
can penetrate to the lungs and blood stream. Such systematic monitoring and poli-
cies to reduce pollution is long overdue, especially in Beijing, for readings of PM
in late 2012 reached over 1000 micrograms, a result of the burning of coal in many
plants, whereas the WHO promotes 25 micrograms as an acceptable health level.
These advanced warning are less easy to provide in the case of major geophysi-
cal events which are largely still unpredictable, although some volcanoes do dis-
play build-ups to major eruptions, and small pre-shocks may precede a major earth-
quake. Historically, these shocks often led people in earthquake-prone areas to take
the precaution of sleeping outside houses to reduce the risk of being buried in a
building collapse. However, there is no guarantee that these geophysical events
will display prior warning; many of the most devastating eruptions of volcanoes or
earthquakes have occurred suddenly. Indeed in the case of geophysical hazards we
still lack the ability to predict earthquakes and most volcanic explosions with any
accuracy (USG). But the network of monitoring stations around the world is be-
coming more sophisticated in recording and publicizing the incidence and intensity
of these events, which can lead to preventative measures by people in areas some
distance from the focal points. However, the areas immediately around these epi-
centres may have little warning before being overwhelmed, as seen in many recent
examples of earthquakes or volcanic eruptions.
Many of these new monitoring devices are beyond the ability of individual cities
to pay for such procedures; hence national government funding and international
co-operation has been needed to establish these stations and to monitor them perma-
nently, often using remote devices to cover large areas to obtain extensive coverage
that will transmit geophysical or weather data to collecting stations in real time and
to quickly dispense the information. The problem is whether the residents of urban
