study zone


The Ogooué is the largest river in Gabon. Its basin drains 215,000 km2 of which 22,000 are outside the national territory. It is bordered to the east by the Congo basin, to the south by the Niari and Nyanga basins, to the east and north-east by the coastal river basins. It is mostly covered by rainforests and wooded savannahs. Covering about 1,000 km, the Ogooué River has its source in the Congo in the Ntalé Mountains, at an altitude of about 840 m.


Western Siberian Plain, one of the world’s largest regions of continuous plains, in the center of Russia. It occupies an area of nearly 3,000,000 km2 between the Ural Mountains in the west and the valley of the Yenisey River in the east. To the north, the West Siberian Plain is bounded by the Kara Sea and to the south by the Torghay Plateau, the Kazakh Highlands (Saryarqa) and the Altai Mountains.