III. Substantiation of Priority of the Trends of the Program
Atmosphere.
Man-made activities cause most heavy pollution and contamination of man's habitat in
atmosphere and hydrosphere. Numerous environmental emissions into atmosphere not only
pollute it, they cause changes in its composition. Of particular concern are changed
concentrations of ozone in the upper atmosphere. This is why global-wide and day-to-day
control over the ozone concentration will allow not only identify the Earth's regions
where "ozone holes" have appeared but also to ferret out the cause(s) and
source(s) of their occurrence.
Preservation of flora, particularly
forests, is a problem of paramount significance, insofar as it is vitally important for
the ecology of other media and primary for the atmosphere.
Up to now forest fires have been one
of the most frequent events that release enormous amounts of soot, carbon black and carbon
dioxide (from 3 to 150 million tones a year) into earth's atmosphere. Worse, forest fires
sharply increase in number with the periodicity of 6 to 7 years. During the recent decade
the problem of forest fire extinguishing has become still more acute because of dramatic
worsening of environmental situation in the world as a whole.
Of particular danger are forest
fires on the territories contaminated with radionuclides, which bring about other and
still worse dangers. In such a territory any fire will cause migration of the
radionuclides as a result of which not only people in that particular area will be
subjected to extra irradiation but in other, far more distant territories too.
While settling together with dust,
the radionuclide particles are accumulated on vast surfaces of trees, bushes, and soft
litter bedding in forest. It was recorded that after the accident at the Chernobyl Atomic
Power Station the concentration of radioactive substances in the forests was 7-10 times as
high as that in meadows and marshes. Coniferous forests kept radionuclides 2-3 times as
much as the deciduous ones.
During a forest fire process the
radioactive particles turn into gaseous or aerosol state and go upward. In fact, the fire
acts as a peculiar pump: it forces upward the said particles together with the heated
masses of air and other combustion products, making them ascend to the upper atmosphere,
sometimes to a height of 6-12 km, and convey over quite large distances. Big fires can
occasionally throw the combustion products with radionuclides as high as the stratosphere.
The life span of a radioactive smoke-aerosol cloud in the lower layers of troposphere (up
to 1.5 km) is less than a week, in the upper troposphere - nearly a month, in the
stratosphere – from 1 to 5 years. This will continuously be accompanied by
"washout" and settling of radionuclides on new territories. This is why any
fires, particularly big ones on the territories contaminated with radiation, constitute
grave danger. Of particular danger are fires in buildings and peat soils, but forest fires
are still much more dangerous.
Fires most frequently occur in the
forest zone of temperate belts which are common in the Northern hemisphere where they
occupy vast territories of Eurasia and Northern America; in the southern hemisphere they
are situated in the western regions of Southern America at 38 latitude south. The main
type of vegetation here is taiga spreading from S-W of Europe through entire Eurasia and
up to the Sea of Okhotsk and N of N. America. Fire-hazardous period in the Northern
Hemisphere starts in April and lasts till September. Each year raging fires break out in
Malaysia, India, Australia, Southern Africa and other regions. In fact most territories of
the Earth are fire-hazardous if one will take into account forest-steppe and forest-tundra
zones, also tundra areas (underground fires).
Fires bring about not only economic
losses. They cause heavy damages to ecology - destruction of wildlife, reduction of green
zones on Earth, changes in climate, erosion of soil, and most pollution of the atmosphere,
etc.
Hydrosphere. Shortage of
water in some regions and countries of the world has put on the agenda one of the most
critical problems – the economy of water resources. By and large the Earth's water
reserves are amounting to 1454 million cubic kilometers of water, these not including
700-800 million cubic kilometers of water contained in the earth's crust. However, fresh
water (salts content below 1 g/cu m) comprises as little as less than 3%, i.e., around 90
million cubic kilometers. With the exception of water contained in the ice fields of
Antarctica, Greenland and other difficult of access places, humanity can use for its needs
only 37.3 thousand cubic kilometers of fresh water, this amount including the water
dropping into the world ocean outlined by the hydrographic network of continents. Another
13 thousand cubic kilometers of fresh water are obtained from subterranean waters. All in
all, the total ready-for-use fresh water resources on the Earth amount to a little more
than 50 thousand cubic kilometers. Worse, the deficit of fresh water on the Earth is
aggravated by its uneven distribution over the globe and by the global cyclic variations
in the rivers discharge with the periods of 2 to 3, 5 to 7, 11 to 13 and 22 to 28 years.
The periods of high and low waters are observed in sync throughout entire regions, yet
they may occasionally differ from one continent to another. To this should be added a
steady decrease of water in land surface water basins. This is attributed to the fact that
during recent decades the level of the World Ocean has been rising on average by 1.2 mm a
year - which is equivalent to a loss of 430 cubic kilometers of surface water annually.
Such loss is due to felling of forests, drainage of marshes and lessened precipitation’s
falling on to the Earth's surface. This draws a conclusion: the problem of water shortage
cannot be solved unless some or other ways of its replenishment are found. The most
probable way here is sewage and rainwater purification. In view of different requirements,
imposed on purification of water of different kinds, the relevant projects will differ in
costs, technical solutions and terms of realization and payback.
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