Why does this sand flow like a river? In some arid areas such as deserts, it is not uncommon for extreme weather such as hail storms to occur. and sometimes causes flash floods. because the density of ice from rain is low, the ice can float on the water so it mixes easily with sand. because this heavy flash flood mixes and moves quickly through the sand, making the flow look like flowing sand.
![](https://s2.save4k.ru/pic/xUSSo_RayaQ/maxresdefault.jpg)