More river comments
- View SourceLast Updated: Tuesday, 5 August, 2003, 23:37 GMT 00:37 UK
Brazil's depleted rivers
By Paulo Cabral
BBC Brazilian Service
Explorer Captain Richard Burton, wrote in August 1867, in Sabara,
Brazil: "Here a man can catch a half a dozen sprat like Piabas simply
by heaving up a bucketful of water and throwing it upon the river
With much pollution and little water in Brazil's Velhas river,
the "flourishing fishing industry" envisaged by Richard Burton
remains an unfulfilled dream for the communities along its banks.
A few fish are still there, but they are tainted by industrial
effluent and human sewage, just like the Velhas river that Burton
navigated for 600 kilometres to reach the Sao Francisco river.
There, river fish face environmental change of a different kind, not
from water pollution but the lack of seasonal floods, which local
fish require for spawning.
"The many dams along the river prevent the big floods that once
allowed so many fish to reach lagoons on the banks and reproduce in a
safe environment," says Alex Godinho, a fish biologist from Federal
University of Minas Gerais.
"Before, a fisherman could catch at the very least five kilos, but up
to 50 kilos, in just one go. Nowadays they are lucky if they get
three kilos in a full day of work."
There are seven hydroelectric plants, with their huge dams, along
the 2,700-km course of the Sao Francisco.
These dams have displaced people and had a significant impact on the
environment, but today could also be used to save the fish.
The Sao Francisco flows along the canyon in northeastern Brazil "We
could create artificial floods using the water from the reservoirs,"
Mr Godinho suggests.
One problem, though, is that all this water is currently used for
"Today water is an asset and it would have to be somehow bought from
the power plants to be used in an artificial flood," says Carlos
Alves, a biologist from Manuelzao Project - an NGO focused on social
and environmental issues on the Sao Francisco basin.
Studies are needed to assess both the cost and the benefits of such a
"Hopefully, we will be able to prove that environmental, economical
and social gains can compensate for the amount of water and money
that would have to be spent on it."
But Mr Alves believes that the project is possible.
"A similar initiative was successfully tested in the United States,
on the Mississippi river," he adds.
The decrease in the flow of water is being felt all the way up to
the mouth of the river.
Biologist Carlos Alves says that flooding would help to reestablish
the fish population "Before that the flow of fresh water was so
strong that it could be detected up to seven kilometres out to sea.
Now it is the ocean water that has encroached upon the river, almost
a kilometre inland," says a tourist guide in the small seaside town
The beaches there are pristine and the vegetation virtually
untouched, making it a great destination for eco-tourism. But to eyes
more used to that landscape the changes caused by human activity are
While we sailed to the mouth of the river, John Lennon - son of
Beatles fans, as you would imagine - pointed to a lighthouse
surrounded by water.
"Can you see that lighthouse? Some years ago it was 500 metres on
shore and now it is partly under water."
The Brazilian Government is also considering taking water from
another river in the Amazon basin and using it to replenish the Sao
Francisco, through gigantic water channels.
This would increase water flow and even allow the diversion of a part
of the Sao Francisco river to other dry areas of the country.
The social benefits, in providing much needed irrigation for
agriculture, would be undeniable. But there are serious concerns
about how political interests might distort the project, and its
potential impact on the environment.
Sewage from four million people is thrown into the Velhas
river "Transferring fish from one basin to the other, as would happen
with this channel, could be disastrous for the river's sensitive
ecosystem," says Carlos Alves.
To clean up the Velhas river authorities will have to tackle another
complicated issue: the limited treatment of sewage in the region.
When Burton visited the Velhas river, he wrote that just a bucket
filled with water there would bring at least half a dozen fish.
"Today the water is full of plastic bags, plastic bottles, shoes and
a lot of pollution that we cannot see, but smell," says Mr Alves.
The biologist explains that nowadays there are two sewage treatment
plants that deal with the output of about one million people in Belo
Horizonte - quite a lot but far less than is required for the
region's four million inhabitants.
But contaminated or not, poverty forces the riverbank community to
live off fish that swim in those waters, which, according to a local,
is only edible "dressed with a lot of lemon to disinfect the flesh
and remove the smell".
The protection of fishing is also the protection of the microbial
habitat--and ultimately the Gaia feedbacks that fill the reseviors.
Brazil's hydrlogy is going through some of the same changes that led
to our Dust Bowl relative to the Mississippi, Rio and Colorado and
the microbial health of the Gulfs of California and Mexico. Sadly,
the world is not learning from our blunders. This year, a rare SOUTH
Atlantic hurricane formed, the first one in more than 10 years . . .
10 worst years for tornadoes in Texas since 1950:
1967 & 1995 232
6 out of the worst 10 occurred in the last 11 years of full data.
Randomly, you'd expect about 2...
Electrically and Gaia speaking, the Gulf of California is Gaia poor
and the Gulf of Mexico Gaia feverish.
The result is the moist air / dry air instabilities that lead to the
point EMF events. IOWs, dry lines and electrical conditions in the
ionosphere that favors the ELECTRICAL instabilities that are
CAP in Arizona and Mexica water use of the Colorado has rendered the
flow to the Gulf of California a trickle. Note the drought in the SW.
Further the Mississippi has been subject to more projects and
subsistance of 25 square miles of delta the past 11 years and
numerous reports of "red tides" as the microbial biosphere has
exploded with the added material flowing into the Gulf of Mexico.
Again, the dielectric of water laden air is substantially greater
than dry air. This causes the capacitive movements from space to
ground to be forced into narrow paths--and then the water is more
conductive and causes more shorts, or strikes.
OTOH, fair weather will have no real direct current path and a larger
area for smooth, wide area capacitive movements--in this cause
consistant fair weather positive voltages to ground of about 250
volts per meter laid out over wide areas.
Tornadic storm "dry lines" allow a pattern of current to be next to
each other, so that there is a strong "wave" of electrical activity.
I would note that the dry lines tend not really to be lines but
circles--such that the electrical activity gets "focused" relative to
the convective area. To give you an idea how powerful the electrical
currents involved are, sometimes a thunderstorm will cause a positive
strike from cloud top to ground--twenty miles away. These strikes are
thought of as positive ions moving down to ground but really are
electrons moving up to the positively charged cloud top. More
typically, the movement is from cloud top, attracting electrons in
the ionosphere (which is conductive) and making the ionosphere above
the nearby dry line negavite, which becomes relatively positively
charged on the ground in an opposing way. This then at electrical
root of strikes, elves and sprites and MOVEMENT of a storm. The
convection and charge separations, IOWs, feeds the movement and
instabilities of the storm. In the end, the cirrus and nucliation
behaviors feed off the electrical dyanmics to bring rain and winds.