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Posts tagged Volga Delta

Environmental Issues for Volga River, Russia – June 16th, 2013

46.0N 49.2E

June 16th, 2013 Category: Image of the day, Rivers MODISAqua

Russia – June 16th, 2013

Draining most of western Russian, the Volga is the largest river in Europe. From its source in the Valdai Hills north east of Moscow the river flows east and south east to the Caspian Sea. This thumbnail images focuses on its delta at the shores of the Caspian Sea, while a larger portion of the river’s meanderings can be seen to the north upon opening the full image.

A large number of tributaries make up the Volga river system the delta where the river enters the Caspian is composed of hundreds of channels and lies 28 m below sea level. For three months of the year the river is frozen for most of its length, the presence of a large number of dams has improved navigation but has reduced the river’s flow.

Consequently the river is suffering from pollution compounded by the fact that it flows through some of the most populated area of the country and includes an important agricultural area. Half of all river freight in Russia uses the Volga, which is connected to the Black sea via the Don river and canals (click here for more information).

Sediments and Phytoplankton Near Volga Delta in Northern Caspian Sea

46.1N 50.9E

May 11th, 2013 Category: Lakes, Rivers, Sediments

Russia – May 10th, 2013

 This image shows the Volga Delta and the northern part of the Caspian Sea, bright green and blue from sediments and phytoplankton. The sedimentation rates and the types of recent deposits in the Northern Caspian Sea are governed mainly by the abundant Volga discharge.

Investigations based on a complex of techniques revealed that the modern deposits in the Northern Caspian Sea involve terrigenous sands and aleurites with an admixture of detritus and intact bivalve shells, including coquina. Generally, these deposits overlay dark grayish viscous clays.

A similar geological situation occurs in the Volga delta; however, the local deposits are much poorer in biogenic constituents. Illite prevails among the clay minerals. The heavy transparent minerals are represented in the coarse aleurite fraction mostly by epidotes, while quartz and feldspars represent the lighter minerals. The sedimentary material in the Volga delta is far from completely differentiated into fractions due to the abundance of terrigenous inflows, which exceed the energy potential of the river (click here for more information).

Ice Along Northern Shores of Caspian Sea

46.7N 50.3E

December 13th, 2012 Category: Lakes

Caspian Sea – December 13th, 2012

As the northern hemisphere winter begins and temperatures drop, ice has begun to form around the northern shores of the Caspian Sea. The Volga Delta can be seen by the eft edge; ice has not formed along its shoreline.

The northern section of the sea is the part most prone to freezing, with ice starting to form around November. During severe winters, the whole northern part of the sea may become ice-covered. In soft winters ice is formed in shoals within the 2-3 meter isobaths (depth contours).

Sediments and Phytoplankton Near Volga Delta – October 22nd, 2012

44.2N 49.4E

October 22nd, 2012 Category: Image of the day, Lakes, Phytoplankton, Rivers, Sediments

Caspian Sea – October 21st, 2012

Sediments and phytoplankton growth color the northern part of the Caspian Sea. While those in the central part of the northern lobe appear milky blue in color, those along the upper shoreline appear bright green. The latter are seeping out of the Volga River Delta, visible as a brown and green fanshaped area on the left side of the image.

Algal Growth Near Volga River Delta, Caspian Sea

45.9N 49.9E

September 23rd, 2012 Category: Phytoplankton, Rivers, Sediments

Caspian Sea – September 17th, 2012

The Volga Delta is the largest river delta in Europe, and occurs where Europe’s largest river system, the Volga River, drains into the Caspian Sea in Russia’s Astrakhan Oblast, north-east of the republic of Kalmykia. The delta is located in the Caspian Depression—the far eastern part of the delta lies in Kazakhstan. The delta drains into the Caspian approximately 60 km downstream from the city of Astrakhan.

Industrial and agricultural modification to the delta plain has resulted in significant wetland loss. Between 1984 and 2001, the delta lost 277 km² of wetlands, or an average of approximately 16 km² per year, from natural and human-induced causes. The Volga discharges large amounts of industrial waste and sediment into the relatively shallow northern part of the Caspian Sea. The added fertilizers nourish the algal blooms that grow on the surface of the sea, clearly visible in the upper half of this image, allowing them to grow larger.

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