The process diagram demonstrates how sand dunes are formed over time due to the movement of sand caused by wind.
Overall, sand dunes are collected when wind carries sand particles from dry ground to wet sand, where they begin to pile up. As the wind continues to blow, the dune gradually becomes larger and more stable.
At the beginning, wind blows sand particles from dry ground on the area of wet sand. When the sand reaches the wet surface, it stops moving and starts to build up in small amounts. This leads to the formation of a small sand dune.
After that, the wind continues to blow more sand particles to the same place. Because of this, the dune grows bigger as more sand is added. The process repeats many times, and the sand piles increase in size.
In the final stage, the dunes remain stable size and stop growing. Although the wind still blows sand particles, they are balanced between both sides of the dune. As a result, the shape remains almost the same and the dune does not become bigger anymore.