The Brazilian Pantanal: An Overview
(Excerpts from the full paper presented in the "uncorrected, advance proof" of The
Pantanal of Brazil, Bolivia and Paraguay, Hudson MacArthur Publishers,
copyright 2000 by Waterland Research Institute)
Incorporating extensive areas of Brazil, Bolivia
and Paraguay, the Pantanal region is the largest floodplain in the world.
Part of the Upper Paraguay River Basin, more than 70 percent of the Pantanal
is located in Brazil, in the states of Mato Grosso and Mato Grosso do Sul.
The Brazilian portion of the Upper Paraguay River Basin extends over an
area of about 361,666 square kilometers, of which 138,183 square kilometers
covers the Pantanal floodplain (Da Silva and Abdon 1988).
Two predominant landscapes can be found in the
Upper Paraguay River Basin: the highlands, and the wetland system or floodplain,
which is the Pantanal. The ecosystems of the Pantanal are highly dependent
upon the rivers which flow from the highlands and which create a dynamic
process worth considering when analyzing the Pantanal. Geologically speaking,
the Upper Paraguay Hydrological Basin is relatively new. It is a sedimentary
basin with a natural process of sediment deposition from the highlands
to the plains. The predominant vegetation in the region is savanna, with
a low density of small trees and a high density of grass. Species from the Amazon and from the Atlantic rainforests,
along with chaco vegetation, can be found there. Because of these diverse influences, the Pantanal
region contains some of the richest biodiversity on the continent (Figure
The weather is classified as a savanna climate
or Aw, according to the Köppen classification. The basin has two distinctive
periods of precipitation, one dry from about April through September, and
one with heavy rain from October through March, with 80 percent of the
annual precipitation during the wet season. The Pantanal floodplain could
be categorized as a big receptor, given that the average precipitation
is only 800 millimeters, while the average precipitation in the surrounding
highlands reaches 1,200 millimeters annually. The rain rapidly drains into
the Pantanal basin, where there is a reduced run-off bed resulting in a
flooded plain. The inclination of the area is very low, about one-to-two centimeters
per kilometer from north to south and about six-to-eight centimeters per
kilometer from east to west, contributing to the wetland formation (Figure 1)(Ministerio do Meio Ambiente 1997).
In addition, the states of Mato Grosso and
Mato Grosso do Sul experienced a process of accelerated development after
the 1970s, when they were considered a new frontier for the expanding agricultural
activities in Brazil. This development resulted in the initial stage of
a large deforestation of the region. However, the Pantanal itself has managed
to escape this ecological disaster. Development in the Pantanal was hindered
by its cyclical hydrological regime, which leads to long periods of flooded
terrain. Therefore, the process of settlement in the region became dependent
upon the changing environment, rather than the environment being impacted
by development and occupation.
The Pantanal’s population totals about 206,000
inhabitants, with a demographic density of approximately 1.8 inhabitants per square
kilometer. In contrast, the average population density of Brazil is about
17 inhabitants per square kilometer. There are several groups of indigenous
populations in the region.
The government of Brazil, through the Ministry
of Environment, Water Resources and Legal Amazon, coordinated the Upper
Paraguay River Basin Conservation Plan (PCBAP: Plano de Conservação
da Bacia do Alto Paraguai). One of its most important results was the delineation
of a regional-scale planning strategy for the basin. The plan was carried
out by teams of experts in different fields. Issues that were researched
included the physical, biotic, social, economic, institutional and legal
aspects of the basin. In addition, a detailed study on hydrodynamics was
carried out, and the final result was the delineation of environmental
zoning for the basin (Figure 4). The basin was divided into 44 areas with
similar characteristics, where potentialities and fragilities were determined.
Based on the PCBAP studies, the five problems
listed below were considered the main problems in the region. (1) An increase
in the sedimentation process of the rivers — mainly the Taquari and Sao
Lourenço rivers — was caused by the increasing human activity in
the highlands. The expanding agricultural activity led to the opening of
new roads and the deforestation of gallery forests. One economic consequence
was that farmers were losing their farmland due to the erosion process
in the highlands, and because the increasingly flooded areas in the plain
were reducing land once used for cattle raising.
(2) Construction of dams and dikes was identified
as another problem. Dams function as a barrier to the water flux (runoff)
and result, on the one hand, in dry lands “protected” from the floodwaters
and, on the other hand, in an increase in the flooded areas outside of
these builds. This causes serious social and economic complications, such
as flooding in urban areas. In addition, the dry lands that are protected
by the dams gradually lose fertility, since the periodic cycle from dry
to flood -- the natural movement of the water -- is responsible for the
natural fertilization of the land. As a consequence, farms protected from
flooding find it necessary to use substantial agrochemicals.
(3) Water contamination, identified as a third
major problem, is caused by three principal activities: (i) agrochemicals
used in agricultural activities; (ii) domestic waste discharged into rivers
without any treatment — and this is one of the most serious problems in
the north Pantanal, where the domestic waste of the city of Cuiabá
is discharged into the Cuiabá River, an important tributary of the
Paraguay River; and (iii) gold and diamond mining. In the state of Mato
Grosso, these mining activities are concentrated in the city of Poconé,
the “door” of the Pantanal (gold mining), and in the cities of Diamantino
and Alto Paraguay (diamond mining); this compromises the Paraguay River
headwaters. The government of Mato Grosso is concerned about the situation
and is working through various means to find the best way to regulate these
activities to produce minimal negative impact on the environment.
(4) Fishing without permission is a problem because
often a specific species of fish is over-exploited, threatening its existence,
and compromising the overall balance of the aquatic ecosystem.
(5) There are two potential problems to be considered
related to large works. The first potential problem is the Bolivia-Brazil
pipeline, which in February, 1999 concluded its first phase. The pipeline project
is designed to increase the available energy to the city of Corumbá,
located in the Pantanal, and could be a good development opportunity for
the area. But without good planning, this project could be a real disaster
for the Pantanal. The second potential problem is the planned improvements
for navigation on the Paraguay River, proposed as the Paraguay-Paraná
Waterway Project, or Hidrovia. On the Paraguay River, for example, two
points are narrower than the rest of the channel and constrain the flow
of water, behaving as a reservoir (Figure 5). Alterations made to these
areas, however, using some of the strong measures proposed in the major
Hidrovia water development project, could have serious consequences, since
they would increase the flow of water. This could have a negative impact
by decreasing the surface area covered by the flooding, and as a result
change the behavior of the flora and fauna.
In the PCBAP studies, the economic activities
most adaptable to the Pantanal’s situation were determined. It was suggested
that the government should stimulate the following activities:
1. Cattle raising. For 200 years, cattle
ranching was cultivated with minimal negative impact on the environment,
since it was carried out largely in natural pastures. This activity could
be considered compatible with the fragility of the area.
2. Tourism. Tourism is another important economic
activity that has to be encouraged by the government through a strategic
plan, in order to prevent or reduce negative impacts.
3. Fishing and sustainable wildlife management.
Fishing and the sustainable management of wild animals, such as caimans
and capybaras, have great potential to be an alternative source of economic
activity. The Brazilian Research Institute is studying alternatives for
developing native species economically in this region.
While the PCBAP plan was being executed, technical
people from our state agencies organized meetings in the municipalities,
where they disseminated the relevant information that was produced by the
plan. The overall results were very positive. After these community meetings,
the local people began demanding action from the state governments regarding
their local environmental problems. Unfortunately, when the plan finished,
these community activities did as well.
Another activity was the creation of the Upper
Paraguay-Pantanal Hydrological Basin Integrated Committee (CIBHAPP), with
representatives from different sectors, including government, the private
sector and non-governmental organizations. CIBHAPP was formed to discuss
questions, problems and interventions related to the basin and to make
demands upon decision-makers to support proper management. This committee,
which is an important indirect result of the Upper Paraguay River Basin
Conservation Plan, is being implemented and supported by the Ministry of
the Environment of Brazil and by the governments of the states of Mato
Grosso and Mato Grosso do Sul.