White water river

The Rio Madeira, a typical white water river

Sharp dividing line at the confluence of the Rio Negro (left, black water river ) with the Rio Solimões (white water river), as the Amazon is also called in the upper section

White water rivers , along with black water rivers and clear water rivers, are among the three dominant river types in the tropics .

The most famous white water rivers in South America are the upper Amazon (Rio Solimões), the Rio Madeira , the Rio Branco and the Río de la Plata , which is also known as the “Silver River”. In Africa, for example, the Blue Nile is one of the white water rivers. Occasionally the term is given a broader definition and is not only related to tropical rivers and, for example, the Danube is referred to in sections as the white water river.

properties

White water rivers are comparatively light due to the high content of suspended mineral matter , their water appears dirty-clay-colored. The actually light brown color only appears white when viewed from an angle. White water rivers arise in recently geologically active areas and therefore carry a large amount of eroded material with them. The turbid substances are often rich in iron and aluminum , and there are also large amounts of electrolytes and nutrients. The pH value is almost neutral or slightly acidic. The conductivity is quite high due to the high mineral content. The visibility is only 10 to 50 centimeters.

fauna and Flora

Due to the nutrient-rich sediments , white water rivers offer a diverse flora and fauna very good living conditions and are therefore more life-friendly than black water rivers and clear water rivers . However, despite the high nutrient content, the growth of plants, blue-green algae and autotrophic bacteria ( primary production ) is low, as very little light penetrates due to the high proportion of suspended matter. Pleuston plants and mollusks are more common in white water rivers . Due to the pH-neutral water, there are far more insects on white water rivers than on rivers of other types.

The floodplain forests on white water rivers are known as the Várzea forest .

literature

• Wilfried Schönborn: Textbook of Limnology . E. Schweizerbart'sche Verlagbuchhandlung, Stuttgart 2003, ISBN 3-510-65204-5

Web links

• www.latein Amerika-studien.at: Limnology: The inland waters of Latin America

Individual evidence

1. ^ ^{A b} W. Schönborn: Textbook of Limnology . Page 368 ff
2. ↑ Gregor Dietrich: Basic aquarium course  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.