A river crosses a cliff and forms a waterfall.

There are many reasons for the formation of waterfalls, and the causes of waterfalls are different in different regions.

The main results are as follows:

1. The degree of softness and hardness of the rocks that make up the bottom of the riverbed are different, and the steep ridges are seriously eroded by the river water.

While the hard rocks hang relatively, and the river flows down here to form a waterfall.

Niagara Falls, on the border between the United States and Canada, for example, has a mottled dolomite roof rock on its riverbed, pressed on top of a series of softer shale and sandstone.

The Niagara River turned over the dolomite wall and fell into a large pool below.

The rolling water continuously eroded the shale, hollowed out the dolomite caves, and pieces of dolomite collapsed, making the cliff always steep. This forms Niagara Falls.

2. The waterfall may also be caused by the capture of the river.

The so-called river raiding refers to the two rivers on both sides of the watershed, in which the more erosive and deeply eroded rivers undercut and erode.

Finally seize part of the river on the other side, making it a tributary of the river.

Due to the large degree of undercutting of the raided river, the riverbed is higher than the riverbed of the raided river.

So when the attacked river merges into the raided river, it often falls, forming a capture waterfall, or suspended river waterfall.

3. On some shores where rivers flow into the sea, the rivers are "shortened" because violent waves often hit the coast, forcing the coast to "retreat".

If the coast is destroyed quite quickly, then the bottom of the river above the sea level will also be "upside down" on the coast, and the river will form a waterfall at the place where it enters the sea.

The most famous waterfalls in the world are as follows:

1. Niagara Falls

Niagara Falls, which straddles the border between Canada and the United States, is the largest transnational waterfall in the world.

Niagara Falls, famous for its beautiful scenery, huge hydropower capacity and challenging environmental protection projects, is a very popular tourist attraction for tourists.

2. Angel Falls

Also known as Angel Falls.

It is located on the Keribo River, a tributary of the Chulun River on the Guiana Plateau in the Venezuelan state of Bol í var in South America, hiding in the dense forests of Venezuela and Guyana.

It is the highest waterfall in the world, with a drop of 979 meters.

The bottom is 150 meters wide.

The waterfall is covered by dense forest and should be seen from the air.

3. Cayetur Falls

A waterfall on the Potaro River, a tributary of the Esquibo River in central Guyana.

The Potalo River falls 226 meters from the Pakalema Plateau and erodes 26 meters down to the rock at the bottom.

The waterfall is 91-106 meters wide and the scenery is magnificent, making it the widest single waterfall in the world.