Deltas in Crisis

During the last decade, a substantial amount of concern has arisen regarding the health of the planets major deltas. Over-exploitation of deltaic resources by humans, the introduction of pollutants and excess nutrients to the rivers, as well as management of river water that feeds deltas has severely damaged the sensitive environments of many deltas. Additionally, reduced sediment loads in many deltas, because of construction of dams, coupled with global sea level rise and or local land subsidence has resulted in widespread loss of deltaic wetlands and fronting sandy barrier shorelines. Because deltaic plains are so heavily relied upon by humans and, in some cases, are densely inhabited by humans, there are for some deltas widespread efforts to try to halt coastal erosion and environmental damages.

For example, the wetlands of the Mississippi River delta have undergone substantial change during the last century with large areas of wetlands converted to open water because of relative sea level rise and erosion by storms. The loss of wetlands across the delta is so severe that communities and infrastructure that were once separated from the open Gulf of Mexico by wetlands are now exposed to open marine water and have become more vulnerable to the damaging effects of storm surge. As a result the state of Louisiana has developed a series of plans to build new land and infrastructure that would help reduce the net loss of land.

Voluntary Reading

For more information on deltaic systems check out these links

• http://toptenonworld.blogspot.com/2012/06/top-10-largest-delta-in-world.html delta scales
• https://futureearth.org/2014/06/26/deltas-at-risk/ dynamics and vulnerability of delta systems