Ana Lucia Lima Barros Dolabella
 
 

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).  

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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 2). 

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 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). 

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 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. 

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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. 

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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. 

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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. 

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(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. 

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(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. 

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(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. 

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(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. 

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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. 

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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. 

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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. 

 

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