You should spend about 20 minutes on this task.
The diagrams below show one way in which sand dunes are formed.
Summarize the information by selecting and reporting the main features and make comparisons where relevant.
Write at least 150 words.
You should spend about 20 minutes on this task.
The diagrams below show one way in which sand dunes are formed.
Summarize the information by selecting and reporting the main features and make comparisons where relevant.
Write at least 150 words.
Step-by-step process of the formation of sand dunes is illustrated in the given diagrams.
Overall, it is clear from all the three diagrams that sand dune formation exclusively depends on the movement of wind.
It can be seen from the first diagram that when wind blows downwards towards the ground, sand particles, which differ in weight and size are blown horizontally on the ground. When these particles are blown over the wet ground, they get adhered, and there forms the primary layer of the sand dunes. However, the sand does not accumulate on the dry ground.
The second diagram shows as the wind continues blowing downwards, more sand sticks to the base layer. The same happens in other wet grounds too.
In the third diagram, it is visible that the sand gets piled up in the form of a pyramid and creates a sand dune. When this happens, the wind which blows downwards the ground moves upwards over the dune formed, and rolls up sand through its top to form another big dune.