Discover the unique landscape of the Pantanal in Mato Grosso and its geographical, climatic, soil and river characteristics.
The geography, the complex network of rivers and the vast wetlands of the Pantanal plain in Mato Grosso constitute a unique landscape on the planet, a heritage of all humanity.
A biogeographical corridor is the term used by ecologists to refer to regions that allow the transit and dispersal of animal and plant species. This is exactly the role played by the Pantanal, located in the transition zone between the Cerrado, the Paraguayan Chaco and the Amazon.
The largest set of wetlands in the world, covering about 210,000 square kilometres, of which almost 140,000 are on Brazilian territory; located in the highest part of the Paraguay River basin, this gigantic system is structured along the Paraguay and Paraná rivers (middle and lower).
The Paraguay River, like the Paraná River in the Pantanal, is one of the few undammed rivers in the world.
However, this vast quadrilateral is drained by other long and flowing watercourses: in the south, the Taquari River (800 kilometres), the Aquidauana River (565 kilometres), the Miranda River (490 kilometres) and the Coxim River (280 kilometres), and in the north, the São Lourenço River (670 kilometres) and the Cuiabá River (650 kilometres).
The Taquari River, which runs for 500 kilometres through the Pantanal, is particularly important because of the length of its basin, which is about 29,000 kilometres.
Ciclo das Águas do Pantanal Matogrossense
GEOGRAPHY OF THE MATOGROSSENSE PANTANAL
1. FORMATION
Nature began shaping this showcase of wildlife some 60 million years ago.
It is estimated that Brazil’s central plateau rose during the Jurassic period, forming a huge shield that eventually broke and collapsed. This created the Pantanal plain.
Over the following geological eras, the force of the elements transformed the area into a flat surface with almost no slope, bordered by large plateaus 600 metres above its flooded bed.
Time has carved into the rocks an incomparable reservoir, eternally fed by the waters of the rivers and tropical rains that swell in the Brazilian quadrant of the Upper Paraguay River.
2. MICROORGANISMS IN THE WATER
The rivers that feed the Pantanal come from the Chapada dos Parecis in the north, the Central Plateau in the east and the Bodoquena mountain range in the south.
When the rivers overflow their beds, these watercourses promote the dispersal of local microflora and microfauna, so that a large number of crustaceans, molluscs and fish are distributed in the bays (the local name for lakes), corixos (channels connecting the bays) and marshes.
The number of microalgae per litre reaches 500 million, more than in the Mississippi and Nile deltas, two of the most fertile regions in the world.
Soil, sand and sediment act as a brake on the water flowing down from the vast plateau that surrounds the Pantanal.
Because of these winding alluvial fans, the water arrives slowly, without enough energy to overcome them.
When the riverbed is clogged with tributaries, the banks are flooded and a shallow layer of water forms, which is soon thickened by abundant rainfall.
The springs in the headwaters and low mountain ranges around the Pantanal feed 175 rivers, and during floods the water rushes over their banks.
The vast, flat expanses of land create an enclosed sea with intense underwater movement.
The sandy outcrops that provide shelter for the cattle are spared from flooding.
At low tide in June, the water recedes, depositing nutrients and animal and plant micro-organisms in the soil.
3. VARIOUS WETLANDS
Fields with bays and capes, flooded fields, mountain ranges with salt ponds, galleries of riverside forest, hawthorns: the Pantanal is full of variety.
The landscapes of the Mato Grosso Pantanal are interwoven, forming a unique ecosystem where relief and hydrography interact deeply.
To better understand the fragments that make up this whole, the Pantanal has been divided into eleven sub-regions – “small wetlands” – each with its own characteristics and history: Nabileque, Miranda, Aquidauana, Abobral, Nhecolândia, Paiaguás, Barão de Melgaço, Poconé, Cáceres, Paraguay and Porto Murtinho.
The Nhecolândia wetlands, for example, where there are salt and fresh water coves with camalote vegetation or even bare vegetation, were named in honour of the owner of one of the oldest farms in the area.
This area has been increasingly affected by the replacement of the gallery forest on the banks of the Taquari River, which feeds the area, with pastures, causing siltation.
Between the Bodoquena mountain range and the Paraguay River is the Nabileque wetland, which, along with the Paiaguás wetland between the Taquari, São Lourenço and Itiquira (also known as Piquiri) rivers, suffers from the most severe flooding.
In the Poconé wetlands, between the Cuiabá and Paraguay rivers, gold mining has caused the rivers to silt up and the fish population to decline.
The Barão de Melgaço wetland, near Chapada dos Guimarães to the north, lies between the Cuiabá and Itiquira rivers and has extensive savannah, much of it covered with grass.
Between the Paraguay River and the Chapada dos Parecis lies the Caceres Pantanal, whose vegetation consists mainly of savannah and grassland, although there are stretches of tropical rainforest due to its proximity to the Amazon region.
The Paraguayan Pantanal, bordered to the west by the Serra do Amolar and the Urucum Massif, is flooded for more than six months of the year.
The Aquidauana wetland, like the Miranda wetland to the west, is less affected by flooding; the latter is home to large areas of carandás and paratudos, the local name for the ipê tree.
The Abobral wetland, east of the Paraguay River, is one of the lowest and one of the first to be flooded.
To the south, the Porto Murtinho wetland has Chaco vegetation and annual flooding. These “small wetlands” are usually grouped into two large regions: Pantanal Sul (in the state of Mato Grosso do Sul) and Pantanal Norte (Mato Grosso).
4. CLIMATE AND SOIL
The climate of the Pantanal, with marked differences between the dry and wet seasons, is predominantly tropical, without oceanic influences.
It is exposed to the invasion of cold masses from the southernmost parts, with rapid penetration through the Pampas and Chaco plains.
Temperatures can drop rapidly, even causing frost, with minimum temperatures around 0°C and maximum temperatures close to 40°C, with an annual average of 25°C.
The dry season, with showers and pleasant temperatures, lasts from May to September.
In July, the heart of the dry season, water is limited to the riverbeds or the swamps and lagoons in the lower parts of the plains.
The rains begin in November, peaking in January and February and lasting until March – this is the Pantanal summer.
As you can see from the graphs below, the northern Pantanal (in Mato Grosso) is generally a few degrees warmer than the south (Mato Grosso do Sul) and receives more rainfall during the rainy season. During this period, about 80 per cent of the Pantanal’s floodplains are inundated.The floods begin in the north and gradually move south, where they combine with the heavy rainfall of the southern region to flood it about two months later.
Total annual rainfall in the region varies between 1,000 and 1,250 mm. This is actually less rainfall than in other neighbouring states, which means that the Pantanal can technically be classified as semi-arid.
During the cooler months of the dry season, the average temperature is around 24°C, but can drop suddenly to coincide with the arrival of cold fronts from the Andes. This usually occurs in July and is known locally as a cold snap, with temperatures dropping to -1°C for short periods.
On the other hand, during the warmer months, temperatures can exceed 40°C and become very uncomfortable due to rain and high humidity.
The temperature rises and falls only immediately after the heavy rains. During this period, the humid and hot region is transformed into a vast wetland where rivers, swamps and lakes mix.
The soil, influenced by rainfall, varies from waterlogged in summer to dry in winter.
The most common soil composition in the Pantanal of Mato Grosso is sandy clay, considered poor in the deepest part, but very fertile in the surface layer due to the deposition of organic matter.
The Pantanal suffers from a number of problems caused by human activity.
These include poorly managed pastures and soya and rice plantations, which can increase the amount of sediment in the rivers and cause erosion. During droughts, the highly damaging practice of slash-and-burn is common.
The situation is exacerbated by human intervention in the headwaters of rivers: the movement of water is so intense that the whole area is affected.
For example, rivers that flow through areas of high agricultural activity can carry sediment, pesticides and other waste to the plains.
Despite this, the Pantanal remains something of an ecological paradise, a vast expanse of pristine rivers and wetlands.
The challenge – for residents, authorities, tourists and all Brazilians – is to keep it that way for generations to come.
See the following publications on the Pantanal
- Mammal and reptile watching in the Pantanal
- Fishing in the Pantanal – Best places, lures, methods and seasons
- Most common fish species in the Pantanal
- Birdwatching in the Mato Grosso Pantanal
- Most common bird species in the Mato Grosso Pantanal
- Flora of the Mato Grosso Pantanal
- Fauna of the Mato Grosso Pantanal
- Pantanal of Mato Grosso – Geography, climate, soil and rivers
- History of the Mato Grosso Pantanal – Discovery and economic development
- Southern Pantanal Region
- Northern Pantanal Region
- Why visit the Pantanal in Mato Grosso?
