Dune Landscape. In physical geography, a dune is a hill of loose sand built by aeolian processes or the flow of water.
Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the stoss side, where the sand is pushed up the dune, and have a shorter slip face in the lee side.
The valley or trough between dunes is called a slack. An erg or sand sea is a large broad, flat area covered with wind-swept sand and/or dunes with little or no vegetation.
Smaller areas are called dune fields. Dunes occur in some deserts, inland and along some coasts.
Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds. Dunes can form under the action of water flow, and on sand or gravel beds of rivers, estuaries and the sea-bed. The modern word dune came into English from French around 1790, which in turn came from Middle Dutch dune. Dunes are made of sand-sized particles, and may consist of quartz, calcium carbonate, snow, gypsum, or other materials. The upwind/upstream/upcurrent
Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the stoss side, where the sand is pushed up the dune, and have a shorter slip face in the lee side.
The valley or trough between dunes is called a slack. An erg or sand sea is a large broad, flat area covered with wind-swept sand and/or dunes with little or no vegetation.
Smaller areas are called dune fields. Dunes occur in some deserts, inland and along some coasts.
Some coastal areas have one or more sets of dunes running parallel to the shoreline directly inland from the beach. In most cases, the dunes are important in protecting the land against potential ravages by storm waves from the sea. Although the most widely distributed dunes are those associated with coastal regions, the largest complexes of dunes are found inland in dry regions and associated with ancient lake or sea beds. Dunes can form under the action of water flow, and on sand or gravel beds of rivers, estuaries and the sea-bed. The modern word dune came into English from French around 1790, which in turn came from Middle Dutch dune. Dunes are made of sand-sized particles, and may consist of quartz, calcium carbonate, snow, gypsum, or other materials. The upwind/upstream/upcurrent
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