If sand dunes disappear, then that means there isn't enough water to push the dunes up. The water is melting away because of GLOBAL WARMING. Search Global Warming for more results.

Sand dunes are built by wind or water

deposition

weathering

Dunes are hills or small mountains made of sand and normally form in the desert. They can move because the wind may blow the sand from one point to another.

Is more steeply sloped than the windward side.

Sand dunes are formed by the action of running water while moraines are formed by the action of moving ice.

Sand dunes move down wind. A simple example: if the prevailing wind is from the west, the dunes will mainly move towards the east.

When the wind blows, it also blows forth tiny bits of sand. When the wind becomes calmer, the sand drops. This is called Erosion (by wind). When the winds get stronger again, the sand could be blown away again. It also keeps laying down if there is also a plant with ground-keeping roots.

The Dutch guys thank their lives on these things, it has kept them from starvation for like 100,000 ( hundred-thousand) years.

Sand dunes are continuously changing due to wind moving the sand around. The appearance of an area covered with sand dunes might remain similar for very long periods of time but the details can well have changed considerably.

Sand dunes on the beach are important and used for protecting the land against potential ravages by storm waves from the sea. The largest complex of dunes are found inland in dry regions associated with ancient lakes.

Sand n1ggers may rob you

plant roots that grow in the cracks of rocks can cause physical........

Too many people walking in the dunes, will trample and destroy the Marram Grass and Lyme Grass that binds the sand dunes together. Once destroyed, the wind can blow off the sand to form hollows known as 'blow-outs' and blow the sand inland.

windy

Sleeping Bear Dunes National Lakeshore is located in Northwestern Lower Michigan along the eastern shoreline of Lake Michigan. The closest city is Traverse City, 25 miles to the east.

See link below.

desert tutles

Illinois State Beach in Zion, IL on the west side of Lake Michigan has dunes (defined as "a hill or ridge of wind-blown sand").

the central part of Algeria

350 miles