Upper Volga near Nizhniy Novqorod, Russia

This image shows the Volga river from Rybinsk (left) to Nizniy Novgorod (lower right) over time. The cities along the river (white patches from left to right) are Rybinsk, Yaroslavl, Kostroma, Kineshma and Nizhniy Novgorod. The Volga is the longest river in Europe. The many reservoirs along the Volga provide hydroelectric power and irrigation to the fertile river valley. The Rybinsk (left) and the Gorkov (right) reservoir are the largest ones shown in this image. The colors in the image result from variations in the surface. Radar backseatter signal depends on soil type, vegetation development, vegetation structure and water content of the soil. Cultivated landcan be recognised as brightly colored patches. acquired on 14 November 2004, 30 September 2007 & 21 June 2009 by Envisat/AS.4R, ©ESA