Land degradation

From CopperWiki
Jump to: navigation, search

Land degradation is a human induced or natural process which affects land negatively in such a manner that it stops functioning effectively within an ecosystem. The decline in the quality of soil, water and vegetation, as a result of land degradation, is of profound importance.

Contents

Why should I be aware of this?

  • A new study has determined that almost a quarter of the world's land area is degrading, often in very productive areas.
  • The study. which shows the extent and severity of land degradation measured in terms of loss of net primary productivity, says that degradation is primarily driven by land management and catastrophic natural phenomena.
  • There is a direct and intimate link between a degraded environment and poverty.

All about land degradation

As a significant portion of the earth's arable lands are affected by degradation, the wealth and economic development of nations decrease. As the land resource base becomes less productive, food security is threatened and there is increased competition for dwindling resources. Many lands need to be cleared for agriculture which reduces species diversity. The causes of land degradation are mainly anthropogenic and mainly agriculture related.

Major causes

Major stresses

  • Accelerated erosion by wind and water
  • Removal of nutrients
  • Acidity increase
  • Salination
  • Alkalinization
  • Destruction of soil structure
  • Loss of organic matter

Areas worst affected

According to the new study, a quarter of the world's population depends directly on these degrading areas. The worst-hit areas are Africa south of the Equator, SE Asia and S China. In terms of the rural population affected, the greatest numbers are in China, with nearly half a billion, India, Indonesia, Bangladesh and Brazil. The African Sahel and around the Mediterranean are much less affected. [1]

Land degradation is threatening the survival of more than 250 million people living in the drylands of the developing world. The poor people in the drylands, which cover about 41% of the earth’s surface, depend mainly on rainfed agriculture and natural rangelands for their survival.

CopperBytes

  • The productivity of some lands has declined by 50% due to soil erosion and desertification. [2]
  • Yield reduction in Africa due to past soil erosion may range from 2 to 40%, with a mean loss of 8.2% for the continent. [2]
  • In South Asia, annual loss in productivity is estimated at 36 million tons of cereal equivalent valued at US$5,400 million by water erosion, and US$1,800 million due to wind erosion. [2]
  • It is estimated that the total annual cost of erosion from agriculture in the USA is about US$44 billion per year, i.e. about US$247 per ha of cropland and pasture. [2]
  • On a global scale the annual loss of 75 billion tons of soil costs the world about US$400 billion per year, or approximately US$70 per person per year. [2]

See also

Soil erosion

References:

  • Land Degradation
  • A quarter of the world's land area is degrading, reveals study
  • Land degradation threatens dryland populations

Source

  1. The Times of India
  2. 2.0 2.1 2.2 2.3 2.4 National Resources Conservation Service