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Archive for October 11th, 2009

The Amazon Basin in the Brazilian States of Amazonas and Pará

3.1S 60W

October 11th, 2009 Category: Rivers

Brazil - September 29th, 2009

Brazil - September 29th, 2009

The Amazon Basin, the largest drainage basin in the world, covers about 40 percent of South America, an area of approximately 6,915,000 square kilometres (2,670,000 sq mi).

In this image, part of the basin in Brazil is visible, from the confluence of the Negro and Solimões (Upper Amazon) Rivers near Manaus in the state of Amazonas (left), to the confluence of the Tapajós and Amazon Rivers near Santarém in the state of Pará (right). The full image shows more of the Negro River northwest of Manaus as well.

The area covered by the water of the Amazon River and its tributaries more than triples over the course of a year. In an average dry season 110,000 square kilometres (42,000 sq mi) of land are water-covered, while in the wet season the flooded area of the Amazon Basin rises to 350,000 square kilometres (135,000 sq mi) .

Lakes in Switzerland Below the Alps – October 11th, 2009

46.4N 6.5E

October 11th, 2009 Category: Image of the day, Lakes

Switzerland - August 31st, 2009

Switzerland - August 31st, 2009

The low-laying areas below the Swiss Alps are home to several lakes, including Lake Geneva, Lake Neuchâtel, Lake Thun and Lake Brienz.

Lake Geneva (or Lake Léman), lower left, is the second largest freshwater lake in Central Europe in terms of surface area. Shared by Switzerland and France, it lies on the course of the Rhône River.

North of Lake Geneva is Lake Neuchâtel, in Western Switzerland. With a surface of 218.3 km², it is the largest lake entirely in Switzerland. The lake is 38.3 km long and no more than 8.2 km wide. Its surface is 429 m above sea-level, with a maximum depth of 152 m. The total water volume is 14.0 km³ and its drainage area is approximately 2,670 km².

Lakes Thun and Brienz are located close together, near the right side of the image. Here, Lake Thun appears blue, while Lake Brienze is bright green.

The alpine Lake Thun takes its name from the Swiss city of Thun, on its northern shore. Its approximately 2,500 km² large catchment area frequently causes local flooding after heavy rainfalls. Lake Thun is actually fed by water from Lake Brienz to the south east, which lies 6 metres higher.

Lake Brienz, similar to its neighbor Lake Thun, takes its name from the village Brienz on its northern shore. The shores are steep, and there is almost no shallow water in the entire lake. Its length is about 9 miles, its width 1½ miles, and its maximum depth 856 feet, while its area is 11½ square miles, and the surface is 564 m above the sea-level.

Chogray Reservoir on East Manych River, Southern Russia

October 11th, 2009 Category: Lakes, Rivers

Russia - September 6th, 2009

Russia - September 6th, 2009

Chogray Reservoir, appearing light grey parallel to the top edge, is an artificial lake on the East Manych River on the border of Stavropol Krai and Kalmykia in southern Russia. It is 49 km long, with an area of 185 square km and a volume of 0.7 cubic km.

The reservoir was constructed between 1969 and 1973, primarily to satisfy the demands of local irrigated farming, many fields of which can be seen here making checked patterns on the surrounding land.

Besides capturing water naturally brought by the tributaries of the East Manych River, Chogray Reservoir receives water from the Terek River and the Kuma River over the Kuma-Manych Canal, which was completed a few years before the lake.

Later on, another irrigation canal, Chernyye Zemli Main Canal, was built, taking water from Chogray Reservoir further east and north, into Kalmykia.