If the water in any place falls from a height of one meter, this site is considered a waterfall.
In the world there are many natural waterfalls, they are born, for various reasons, and sooner or later die.
Most often, the waterfalls are formed when inriverbed more hard rock gives way to soft. Water is constantly erodes the river bottom, and if one breed is softer than the other, this process will be uneven. Gradually form a hard rock ledge, which is getting higher and higher, the water begins to blur water for him, as it has not only the power of the current, but also the power of falling from a height.
The harder the rock, which is formed from the ledge,the longer it will last a waterfall, and if it is eroded, albeit more slowly than the land behind it, you will soon fall away as the channel surface equal. Also falls gradually move upstream as rock ledge, no matter how hard it may be, it is still being eroded.
Falls can occur not only because ofNatural blur the channel for a long time. Sometimes there is some kind of natural disaster - landslide, volcanic eruption, earthquake, and the flow of the river is blocked. Gradually the river level reaches the height of the obstacles and the water begins to fall from a height into the mainstream, where it proceeded before. These waterfalls appear very quickly.
Often, whole cascades formed smallfalls, this happens through a suitable composition of the rocks in the channel site. Occasionally falls comb can not withstand the constant water load in only one place, it remains higher open, but the water in it breaks its thin bed and no longer falls straight down and rolls down the inclined chute.
Some waterfalls occur where the plateau turns sharply in the lowland, in the world are many places with such relief. Full-flowing rivers plateau steeply falling down from a great height.
The cause of some waterfalls steelglaciers. At the time, large glaciers formed long narrow valleys and small glaciers crashing into the side of them, creating openings in the main valley cliffs. Now of these openings are flowing mountain rivers. Many of these waterfalls of glacial origin in the Alps.