Land loss

This article is about land loss due to erosion. For anthropogenic loss of productive land with topsoil, see land consumption.

Summary table of the common physical and anthropogenic causes of coastal land loss.

Land loss is the term typically used to refer to the conversion of coastal land to open water by natural processes and human activities. The term land loss includes coastal erosion. It is much broader term than coastal erosion because land loss also includes land converted to open water around the edges of estuaries and interior bays and lakes and by subsidence of coastal plain wetlands. The most important causes of land loss in coastal plains are erosion, inadequate sediment supply to beaches and wetlands, subsidence, and global sea level rise. The mixture of processes responsible for most of the land loss will vary occurring the specific part of a coastal plain being examined. The definition of and loss does not include the loss of coastal lands to agriculture, urbanization, or other development.

Wetland loss

Although seemingly related, wetland loss, is defined differently than land loss. Commonly, wetland loss is defined as the conversion of vegetated wetlands into either uplands or drained areas; unvegetated wetlands (e.g., mudflats); or (submerged habitats (open water). According to this, and similar definitions, wetland loss includes both land loss and land consumption as components of it. In historic times, both wetland and land loss typically are the result of a varying, often controversial mixture of natural and anthropogenic factors. There are other definitions of wetland loss commonly used. For example, some researchers defined wetland loss as "the substantial removal of wetland from its ecologic role under natural conditions."

See also: No net loss wetlands policy

Land loss and deltas

Because of a highly variable combination of sea level rise, sediment starvation, coastal erosion, wetland deterioration, various types of subsidence, and various human activities, land loss within delta plains is a significant global problem. The large delta plains of the world, including the Danube, Ganges, Brahmaputra, Indus, Mahanadi, Mangoky, McKenzie, Mississippi, Niger, Nile, Shatt el Arab, Volga, Yellow, Yukon, and Zambezi deltas, have all suffered significant land loss as the result of either coastal erosion, internal conversion of wetlands to open water, or a combination of both. For the 15 deltas studied by Coleman and others, these deltas experienced a total irreversible land loss of 5,104 km² (1,971 sq mi) of wetlands between the early 1980s and 2002. During this period, the total average land loss for all of these deltas was about 41 km² (16 sq mi) per year. In case of the Mississippi River Delta, they found that in a 12-year period, some 253 km² (98 sq mi) of wetlands had been converted to new open water at a rate of 21 km² (8.1 sq mi) per year.

See also

• Coastal erosion in Louisiana
• Mississippi River Delta
• Wetlands of Louisiana