The Chaco Plain: Covering Argentina, Paraguay, And Bolivia

The low-lying plain that covers parts of Argentina, Paraguay, and Bolivia is the Gran Chaco, also known as the Chaco Plain. It is a sparsely populated lowland region with a semi-arid climate and is divided among eastern Bolivia, western Paraguay, and northern Argentina. The Gran Chaco covers an area of about 647,500 square kilometres (250,000 square miles) and is located west of the Paraguay River and east of the Andes. The region is mostly an alluvial sedimentary plain, with elevations reaching no higher than 300 metres (980 feet) and averaging 125 metres (400 feet). The landscape is mostly flat and slopes gently eastward towards the Paraguay River.

The Gran Chaco, a sparsely populated lowland forest

The Gran Chaco is a sparsely populated lowland forest that spans parts of Argentina, Paraguay, and Bolivia. Covering an area of about 647,500 km2 (250,000 sq mi), it is located west of the Paraguay River and east of the Andes. This lowland forest is known for its hot and semi-arid climate, with temperatures among the highest on the continent.

Historically, the Gran Chaco has been divided into three main parts: the Chaco Austral or Southern Chaco, the Chaco Central or Central Chaco, and the Chaco Boreal or Northern Chaco. The Chaco Boreal, which covers more than 95,000 square miles (246,000 square km), constitutes the northeastern part of the Gran Chaco. This region is mostly flat, sloping at a gentle 0.004-degree gradient towards the east.

The landscape of the Gran Chaco is characterised by alluvial sedimentary plains. The area is home to a rich variety of animal and plant life, with around 3,400 plant species, 500 bird species, 150 mammal species, and 220 reptile and amphibian species. The dominant vegetation type is xerophytic deciduous forests, with multiple layers including a canopy, subcanopy, shrub layer, and herbaceous layer. The Chaco Boreal can be further divided into two parts: the Alto Chaco (Upper Chaco) and the Bajo Chaco (Lower Chaco). The Alto Chaco is very dry with sparse vegetation, while the Bajo Chaco has a more humid climate and is known for its swampy plains and savanna vegetation.

The Gran Chaco has a long history of human occupation, with various nomadic groups resisting Spanish control of the region from the 16th to the early 20th centuries. In the 20th century, the region became the site of the Gran Chaco War between Paraguay and Bolivia over supposed oil deposits. Today, the Gran Chaco remains relatively underdeveloped, with a population of around 100,000 in Paraguay. However, it continues to be an important source of natural resources, including timber, tannin, and agricultural products.

The Ñeembucú Plain

The Paraneña region, which includes the Ñeembucú Plain, covers about 95% of Paraguay's population and is characterised by highlands in the east that slope toward the Paraguay River, becoming lowlands along the river that are subject to flooding. The region is drained by rivers that flow westward to the Paraguay River, as well as eastward to the Paraná River. The Paraguay River separates the Paraneña region from the Chaco region to the west.

The Chaco region, in contrast, is a vast plain with elevations reaching no higher than 300 meters (980 ft) and averaging 125 meters (400 ft). Covering more than 60% of Paraguay's total land area, the Chaco plain slopes gently eastward toward the Paraguay River. The Paraguayan Chaco is subdivided into two parts: the Alto Chaco (Upper Chaco) or Chaco Seco (Dry Chaco), and the Bajo Chaco (Lower Chaco) or Chaco Húmedo (Humid Chaco).

The Pantanal region

The Pantanal is located in the Gran Chaco region, which spans across eastern Bolivia, western Paraguay, northern Argentina, and a portion of Brazilian states, Mato Grosso and Mato Grosso do Sul. The name "Chaco" comes from the Quechua word "chaqu", meaning "hunting land", reflecting the region's rich animal life. The Pantanal is part of the Chaco Boreal or Northern Chaco, which lies north of the Pilcomayo River and west of the Paraguay River.

The landscape of the Pantanal is characterised by its flat, sloping terrain, with elevations reaching no higher than 300 meters. The region experiences a tropical wet-and-dry climate, with seasonal variations that alternately flood and parch the land. The combination of flat topography and seasonal flooding creates a challenging environment for agriculture and infrastructure development.

The Pantanal has a human population of approximately 100,000 people, with a significant portion residing in the Paraguayan part of the region. The area remains relatively underdeveloped, with limited access to all-weather roads and basic infrastructure. However, efforts have been made to improve accessibility, such as the construction of the Trans-Chaco Highway and the paving of Brazilian highways in the region.

The Paraná Plateau

The Northern Upland, the Central Hill Belt, and the Central Lowland constitute the lower terrain lying between the escarpment and the Río Paraguay. The Northern Upland occupies the portion northward from the Aquidabán River (Río Aquidabán) to the Apa River on the Brazilian border. It consists mostly of a rolling plateau about 180 metres (590 ft) above sea level and 76 to 90 metres (249 to 295 ft) above the plain farther to the south. The Central Hill Belt encompasses the area in the vicinity of Asunción, featuring small, isolated peaks and the region's only lakes. Between these two upland subregions lies the Central Lowland, an area of low elevation and relief, sloping gently upward from the Río Paraguay toward the Paraná Plateau. The valleys of the Central Lowland's westward-flowing rivers are broad and shallow, and periodic flooding of their courses creates seasonal swamps.

The Chaco region

The Chaco has a semi-arid to semi-humid climate, with a six-month dry season and high temperatures. The region experiences seasonal variations, with flooding during the rainy season and parched conditions in the dry season. The Chaco is known for its rich biodiversity, hosting around 3,400 plant species, 500 bird species, 150 mammal species, and 220 reptile and amphibian species.

The Chaco has a long history, dating back to indigenous nomadic groups such as the Guaycuru, who resisted Spanish control from the 16th century until the early 20th century. In the 1920s, Mennonite colonies were established in the region, and it became the site of the Chaco War, a conflict between Bolivia and Paraguay over control of its northern part and potential oil deposits. The war ended with a Paraguayan victory, and a 1938 treaty granted Paraguay three-quarters of the disputed territory.

Today, the Chaco remains relatively underdeveloped, with a population of around 100,000 in Paraguay. However, it has seen some infrastructure development, with the construction of highways and roads in recent decades. The region also has agricultural potential, with large tracts of fertile soil suitable for farming.

Frequently asked questions