2) Water resources in the Brazilian Northeast; brief history
In
ancient times the Brazilian Northeast was inhabited by numerous
indigenous societies among which the largest were the tupinamba,
the
potiguara, the caete,
the tapuia,
the tupina
and the tupinikin.
These nations mainly dedicated to fishingi
and roça
farmingii
. According to historical chronicles and documents the population for
the whole region at that time could be estimated at several millioniii.
The
arrival of Portuguese navigators took place during the late fifteenth
and early sixteenth century (Alvaro Cabral arrived by “accident”
in 1497). In 1532, Martin Afonso de Sousa established two colonies in
the island of São Vicente and in Piratininga (present São Paulo).
Two years later King João III divided the coast in 14 hereditary
captaincies, most of which were not occupied immediately. The
Northeastern Captaincies were Maranhão, Pernambuco, Bahia and
Ilheus).
In
1535, the city of Olinda was founded (in the territory of present
Pernambuco), and in 1537, the city of Recife, also in Pernambuco, was
established. In 1549 was founded Salvador in the Itaparica bay, and
at a later date, João Pessoa (1585), Natal (1599), Fortaleza (1611)
and São Luis (1612). During the sixteenth and seventeenth century
the economy focused on sugar cane production, based on native slave
labor. During that period indigenous people were captured and forced
to work in the plantations. Mistreatment, disruption of communities
and families, and repression, reduced native population dramatically
and to compensate for the lack of labourers, African slaves were
brought (also by force) from Africa to do the plantation work.
Descendants
from those native populations and African forced migrants (including
many who managed to escape and establish rebel communities or
quilombos in
the interior) represent the majority of the population in
contemporary Brazilian Northeastern urban and rural societies.
The
extremely unequal distribution of land property, as a result of
concentrated grants by the Portuguese and Brazilian Crowns, which
continued without major changes in the Republic period, as well as
the highly inappropriate management of native ecosystems (logging and
burning of primary forests and bush-lands, inadequate farming,
over-grazing, over-irrigation) produced a badly degraded landscape.
During
colonial times, the largest river of the region, the São Francisco,
became the main route of penetration into the continent from the
coastal Atlantic settlements.
Bandeirantes (slave raiders) would
navigate the river to capture slaves for the sugar cane plantations,
and at a later date (early XVIII century) miners and other
adventurers used the river to reach the gold producing areas of Minas
Gerais (Ouro Preto).
During
the nineteenth century the São Francisco became a transportation
route for people and for merchandises produced in the interior.
The
historical importance of the river São Francisco cannot be
underestimated. Because it is the only river entering deeply into the
continent from the Atlantic façade, it has been the backbone of many
historical and political events in Brazil. It is called “the river
of Brazilian unity”, and, in fact, it crosses vast expanses of the
Brazilian interior and, in that way, provided one unique route for
exchange and communication between communities, cities, producing
areas and commercial centers.
However,
the heavy exploitation of the basin, mainly through extensive
processes of deforestation, produced deep changes in river dynamics
and water quality. Droughts and floods became more prevalent, run-off
rates and erosion augmented, and consequently, river water, presently
loaded with sediments (i.e. clay and silt, even sand and pebbles) and
increased turbidity, has lost a great deal of its original biological
productivity.
During
the twentieth century, several large water projects were developed in
the basin, including the three largest dams (Tres Marias, Sobradinho
and Itaparica) and numerous irrigation schemes. The dams produced a
mixed balance: on the one hand, they reduced the sediment load
arriving to the lower basin and regularized the flow, on the other
hand there was increased evaporation in the lakes and consequently
decrease in the average water available in the lower stretches of the
river. Also, the lakes were utilized as sources of water for several
irrigation projects in Minas Gerais, Bahia and Pernambuco introducing
additional modifications to the São Francisco hydro-system.
Lately,
a project of water transposition was proposed to deviate water from
the São Francisco dams of Sobradinho and Itapacarica, towards
several northeastern basins in the Northeast (i.e. Jaguaribe, Acodi,
Piranhas and Paraiba rivers) and to smaller basins in Central and
Western Pernambuco. This issue is explored in section 6 of this
paper.
i
Potiguara means “shrimp eaters”
ii
Roça planting is done through partial logging and burning. Main
crops included manioc, corn, sweet potato and tobacco.
iii
It is difficult to know the exact numbers. Alfonso Braz wrote in
1551: “There are so many of them and land is so good and their
increasing in such numbers, that if they weren’t constantly in war
and eating each other the land couldn’t contain them” Source:
“Red Gold” from John Hemming, 1978
