The majestic and thunderous power of water cascading down a waterfall, with its roaring might and breathtaking beauty, is awe-inspiring and remarkable.

It is hailed as one of the most spectacular and awe-inspiring natural phenomena on Earth.

Waterfalls can be found in regions around the world with significant elevation differences, especially in high mountain areas. However, they inevitably evoke curiosity: Where does the water in waterfalls come from, and why does it never stop flowing?

Generally, waterfalls are formed where water flows over a significant drop, creating a unique landscape. As long as the height is sufficient, waterfalls can form. The source of a waterfall can typically be traced back upstream along a stream or river, with additional tributaries joining along the way.

The ultimate source of a waterfall is a large reservoir of water, which originates from underground sources influenced by atmospheric pressure, as well as rain and snowmelt. Therefore, the water source of waterfalls is usually abundant, although this applies more to smaller waterfalls rather than large ones.

During a river's flow, waterfalls are a temporary feature. Due to factors such as the drop height, volume of water, types of rocks, and other factors, they eventually disappear. In places where waterfalls exist, rivers always erode upstream, attempting to flatten high areas and make the riverbed gentler. Water erosion is powerful enough to break down even the hardest rock layers.

The faster the flow of the river, the stronger its erosion force on the riverbed and banks. Rivers continually erode the upper parts of waterfalls, causing rocks to break and fall, resulting in the gradual retreat of the waterfall's position upstream and a reduction in its drop height.

In some cases, the location of the waterfall may recede upstream due to cliffs or steep slopes being washed away by the flow of water, while in other cases, this erosion tendency tends to cut downwards and diagonally across the entire river section containing the waterfall. Over time, any one or two of these factors will gradually cause the waterfall to disappear.

Many of the Earth's major waterfalls exhibit a clear trend of "recession." For example, Niagara Falls, with a current drop of about 50 meters, was estimated to have a drop of around 100 meters at its previous location downstream based on rock layers. The waterfall recedes upstream by over 1 meter each year, and the drop is decreasing. At this rate, in another 50,000 years, Niagara Falls will completely disappear.

Although all waterfalls will eventually vanish, new ones are also born over long ages. The Earth's geological movements, such as the uplifting of mountains and plateaus, as well as the fracturing and displacement of rock layers, create conditions for the birth of new waterfalls. Waterfalls, these beautiful natural landscapes, will not disappear from the Earth.