Delta - a special ecosystem

most people is that this river delta, but not all, think about the role that it plays in the lives of all species of flora and fauna.What does she like?Delta - is formed by sediments of the river lowlands, located in its lower reaches.Most often it is strongly penetrate the network of ducts and hoses.This creates a particularly lowland ecosystem.Delta got its name from one of the letters of the Greek alphabet, which in its form is strongly reminiscent of the ancient Nile delta triangle.

In the process of long-term interaction between river flows, sea or ocean unrest surges wind-currents, tides, and sediment load in the river each form a unique delta, which can take up to a hundred thousand or more square kilometers.In the Ganges, it takes almost 106 thousand sq., while the Amazon - 100 thousand square kilometers.

River Delta may start hundreds of kilometers from its mouth.Delta put forward some rivers in the sea or ocean, while others - not.Under the influence of tidal rivers such as the Amazon, Amur, the Ob, Taz, Pur Delta have not beyond their native shores.

When the water in the river has almost the same density of sea water, the delta becomes a cone shape (for example, the Nile).If river water is rich in precipitation, it becomes more dense than the sea, so the delta under its influence becomes an elongated shape.At low density of river water of the delta formed with a large number of hoses and ducts (p. Mississippi).

Most of the rivers of the world have developed the delta alluvial (alluvial) operations.These are the Volga, Lena, Terek, the Northern Dvina, Kuban, Neva.Many southern rivers have developed "smoothly" with rich vegetation and varied wildlife.They are significant fisheries.The vegetation is represented by various grasses, reeds and rushes, shrubs and trees.They settle poultry and like various kinds of animals.

difficult to overestimate the importance of moisture and soil fertility, located in the delta of the river.In many countries of the world is growing at a significant part of these crops.Juicy grass on moist meadows, located in the lower reaches of rivers, are an excellent feed for livestock.Valley of the Ganges, the Nile, the Yellow River, the Danube are areas with intensive agriculture.

peculiar is the delta of the Neva River, which flows through the swampy lowlands and flat Neva.This river is conventionally divided into 2 parts (in character mode) top (source - Ivanovo rapids), a length of 30 km, and the lower (Ivanovo rapids - the mouth), the length of 44 km.In the lower reaches (about 15 km from the mouth) forms a wide delta of the Neva, abounding channels, branches, islands and channels.It arose as a result of surges and ebbs of water from the sea and under the influence of the current of water.In the delta of the Neva largest islands are Krestovskiy, Vasilevsky, Petrograd, the Decembrists.Her sleeves are Small and Big Neva Small, Medium and Large Neva.The most famous canals - Bypass, Sea, hook, Griboyedov.