GEO Brasil - UNEP

the use of the soil do not exacerbate these problems
Sand and gravel extraction should also be cited as a critical hydrologic situation,
as well as the remaining mineral activities which are rather spread out around the
Brazilian territory, including prospectingThese practices, when carried out without
the necessary knowledge, preventive measures or environmental recovery, affect
water bodies not only by silting them up but also with physical and chemical
pollution
Pollution, whether scattered or focused, contributes to an accelerated
eutrophication of lakes and reservoirs The presence of nutrients such as
phosphorus and nitrogen enables the proliferation of algae
Biodiversity destruction has been
provoking a decrease in the availability
of water resources through river and
reservoir obstruction and the physical
and chemical loss of soils All these
factors restrain the earth‘s biological
potential This not only reduces
agricultural productivity but also
causes problems to populations
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Underground Waters in
Brazil
Underground water is the part of
meteoric water-rain, fog and snow,
mainly, which infiltrates and moves
through the lands of a given water
basin However, once its displacement
speed is very low (in terms of cm/day
order), underground water flows
towards rivers, supplying basic
drainage, specially during rationing
periods or droughts
the state of the environment in Brazil
While moving through the interstitial
or fissure porous environment,
underground water is submitted to
processes of natural purification in
levels never achieved by conventional
treatment methods As a
consequence, the alternative use of
underground water for human supply
is frequently cheaper and it is the main
support for water businesses related
to bottled water or water put in “pipe
trucks”
The combination of these factors leads populations to a state of extreme poverty
A migration process is then established in the search for more favourable survival
conditions In turn, this migratory process aggravates the infra-structure problems
in urban centres
Many irrigated areas show signs of salinity, which is a consequence of lack of
investments in draining systems For example, signs of salinity or soil density
in approximately 30 percent of the area are present in the 600,000 irrigated hectares
in this region
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From Wells to
Underground Flow
Systems
In General the traditional hydrogeological
studies in Brazil comprise,
the statistical analysis of data on well
depths, water levels, flows and quality
This is true regardless of the fact that
there is little technical or scientific
consistence to that information
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