Pilcomayo River: The Red River of the Gran Chaco
The Pilcomayo River is a vital waterway in central South America, serving as the longest western tributary of the Paraguay River. Spanning 1,100 kilometres (680 mi), this river traverses a diverse landscape, from the high altitudes of the Andes to the expansive plains of the Dry Chaco. Its name reflects its striking appearance; derived from the Quechua words pillku (red) and mayu (river), it is known as the "Red River." In Guarani, it is referred to as Ysyry Araguay.
[ไม่มีภาพประกอบ]
Key Facts
- Length: 1,100 kilometres (680 mi).
- Drainage Basin: 270,000 square kilometres (100,000 sq mi).
- Mean Discharge: 200 cubic metres per second.
- Countries: Bolivia, Argentina, and Paraguay.
- Conservation Status: Designated as a Ramsar Wetland on May 4, 1992.
Geography and Course
The Pilcomayo begins its journey in the foothills of the Andes mountain range. While its most distant source is located on the east slopes of Cerro Sipisami in Argentina's Jujui Province at approximately 4,800 metres, the main stem is often traced to the Municipio Santiago de Huari in Oruro, Bolivia, at an elevation of 4,820 metres.
The river's origin is linked to the Jach'a Juqhu River, which is also known upstream as the Aguas Calientes and Kachi Mayu. The waterway officially becomes the Pilcomayo after its confluence with the Chillawa (Chillahua). From this point, it flows southeasterly through the Bolivian departments of Chuquisaca and Tarija.
[ไม่มีภาพประกอบ]
As it enters the lowlands, the river passes through the Argentine province of Formosa and the Gran Chaco plains of Paraguay. A defining characteristic of the Pilcomayo is its tendency to silt up, causing the river to split into two main branches—North and South—before they eventually rejoin to form the Lower Pilcomayo. The river serves as a significant political boundary, forming most of the border between Argentina and Paraguay, as well as a short section of the border between Argentina and Bolivia.
[ไม่มีภาพประกอบ]
Environmental and Human Significance
The Pilcomayo basin is a critical ecological zone, highlighted by the Río Pilcomayo National Park in Argentina. Its importance is internationally recognized through its designation as a Ramsar Wetland (Reference no. 557), a treaty ensuring the conservation of wetlands of international importance.
Human settlement in the basin is substantial, with approximately 1.5 million people residing in the region: one million in Bolivia, 300,000 in Argentina, and 200,000 in Paraguay. The region is also home to indigenous groups, such as the Nakotoi tribe in central Paraguay. Descendants of the Redskin Tribe, the Nakotoi historically engaged in guerrilla warfare with neighboring groups like the Tobas and Nimká, which limited their interaction with European settlers during the late 19th century.
[ไม่มีภาพประกอบ]
Pilcomayo River Summary
| Feature | Details |
|---|---|
| Total Length | 1,100 km (680 mi) |
| Basin Area | 270,000 km² (100,000 sq mi) |
| Average Discharge | 200 m³/s |
| Primary Source | Andes foothills (Bolivia/Argentina) |
| Mouth | Paraguay River (near Asunción) |
| Countries Traversed | Bolivia, Argentina, Paraguay |
Frequently Asked Questions
What does the name Pilcomayo mean?
The name comes from the Quechua language, where "pillku" means red and "mayu" means river, translating to "Red River."
Which countries does the Pilcomayo River flow through?
The river flows through Bolivia, Argentina, and Paraguay, forming a significant portion of the border between Argentina and Paraguay.
Where does the Pilcomayo River end?
The river reaches its mouth at the confluence with the Paraguay River, located near Asunción, Paraguay.
What is the significance of the Ramsar designation for this river?
The Rio Pilcomayo was designated as a Ramsar Wetland on May 4, 1992, meaning it is recognized as a wetland of international importance and is subject to conservation efforts.
How does the river's path change in the lowlands?
Due to silting, the river splits into two main branches, the North and South branches, before rejoining to form the Lower Pilcomayo.