Earth Snapshot RSS Feed Twitter

Search Results for "Volga Delta":

Environmental Concerns for the Volga Delta, Russia

46.7N 47.8E

July 8th, 2009 Category: Lakes, Rivers

Russia - June 21st, 2009

Russia - June 21st, 2009

The Volga River and Delta stand out as dark green areas in this image of Russia along the shores of the Caspian Sea. Dark brown sediments pour into the sea from the river.

Despite the seemingly dense sediments visible, regulation of the Volga through construction of a series of dams has reduced sediment supply to the delta and prevented the spawning migrations of sturgeon and other fish.

These dams have adversely affected the natural hydrology of the river, in other ways, such as causing reduced river flows for much of the year and irregular, aseasonal flooding.

The Volga is also subject to serious pollution from industrial and agricultural sources. There are huge unregulated industrial complexes along the Volga dams, while the floodplain of the lower Volga is intensively cultivated, with extremely high levels of pesticide and herbicide use.

Here, such chemicals have incited algal growth, visible as green- and blue-colored areas in the Caspian Sea.

A further problem, of currently undetermined cause, is the recent and ongoing rise in level of the Caspian Sea. This has led to a northward retreat of the foredelta, so that the Ramsar site is becoming inundated and increasingly dominated by deeper, open water.

The Three Zones of the Volga Delta, Russia – May 20th, 2009

46.7N 47.8E

May 20th, 2009 Category: Image of the day, Lakes, Rivers

Volga Delta, Russia - May 17th, 2009

Volga Delta, Russia - May 17th, 2009

The Volga Delta is located in Russia’s Astrakhan Oblast. It is the largest inland river delta in Europe, and occurs where Europe’s largest river system, the Volga River, drains into the Caspian Sea in the Caspian Depression. The far eastern part of the delta extends into Kazakhstan.

The delta lies in the arid climate zone, characterized by very little rainfall. The region receives less than one inch of rainfall in January and in July in normal years.

Strong winds often sweep across the delta and form linear dunes. Along the front of the delta, one will find muddy sand shoals, mudflats, and coquina banks. Green algae, nourished by fertilizers, is present in the waters around the delta.

The Volga Delta has grown significantly in the past century because of changes in the level of the Caspian Sea. In 1880, the delta had an area of 3,222 km². Today the Volga Delta covers an area of 27,224 km² and is approximately 160 km across.

The changing level of the Caspian Sea has resulted in three distinct zones in the delta. The higher areas of the first zone are known as “Behr’s mounds,” which are linear ridges of clayey sands ranging from 400 m to 10 km in length, and averaging about eight meters in height. Between the Behr’s mounds are depressions that fill with water and become either fresh or saline bays.

The second zone, in the delta proper, generally has very little relief (usually less than one meter), and is the site of active and abandoned water channels, small dunes and algal flats.

The third zone is composed of a broad platform extending up to 60 km offshore, and is the submarine part of the delta.

Numerous Channels and Streams of Volga River Delta, Russia

46.0N 48.5E

June 6th, 2009 Category: Rivers

Volga River Delta, Russia - June 2nd, 2009

Volga River Delta, Russia - June 2nd, 2009

The Volga is the largest river in Europe in terms of length, discharge, and watershed. It belongs to the closed basin of the Caspian Sea.

Rising in the Valdai Hills 225 meters (738 ft) above sea level north-west of Moscow and  flows through the western part of Russia, before discharging into the Caspian Sea below Astrakhan at 28 meters (92 ft) below sea level.

The Volga Delta has a length of about 160 kilometres and includes as many as 500 channels and smaller rivers. Here, such channels appear white and grey, making a streaked, lightning-like pattern across the radar image.

The largest estuary in Europe, it is the only place in Russia where pelicans, flamingoes, and lotuses may be found.

The Volga River Delta in the Caspian Sea – April 19th, 2009

April 19th, 2009 Category: Image of the day, Rivers

Caspian Sea - March 31st, 2009

Caspian Sea - March 31st, 2009

The Volga Delta is the largest inland 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. Although some clouds partially obstruct the view of the area, the delta is visible on the northwestern shores.

The Volga Delta has grown significantly in the past century because of changes in the level of the Caspian Sea. However, in recent years 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, allowing them to grow larger.

This algae is responsible for the green color of the water immediately around the delta, and may also be contributing to the green color present in the rest of the sea’s northern section.

The Danube Delta, Romania and Ukraine – August 16th, 2009

45.0N 29.0E

August 16th, 2009 Category: Image of the day, Lakes, Rivers

Romania - July 27th, 2009

Romania - July 27th, 2009

The Danube Delta is the second largest delta in Europe, after the Volga Delta, and is the best preserved on the continent. The greater part of the Danube Delta lies in Romania (Tulcea county), while its northern part, on the left bank of the Chilia arm, is situated in the Ukraine (Odessa Oblast).

The approximate surface is 4152 km², of which 3446 km² are in Romania. If the lagoons of Razim-Sinoe (1015 km² of which 865 km² water surface; situated in the south, but attached to the Danube Delta from geological and ecological perspectives, as well as being the combined territory of the World Heritage Site) are to be added, the considered area of the Danube Delta grows to 5165 km².

Here, these lagoons appear greenish yellow, as do the branches of the river and the sediments spilling from them into the Black Sea. Inland, much of the terrain is used for agriculture, and many rectangular fields can be seen.