Search results
Results from the WOW.Com Content Network
Aridification is the process of a region becoming increasingly arid, or dry.It refers to long term change, [1] rather than seasonal variation. It is often measured as the reduction of average soil moisture content.
For example, temperature increase by 1.5–2.1 percent across the Nile Basin over the next 30–40 years could change the region from semi-arid to arid, significantly reducing the land usable for agriculture. In addition, changes in land use can increase demands on soil water and thereby increase aridity. [6]
Aridity is different from drought because aridity is permanent whereas drought is temporary. [1] A number of aridity indices have been proposed (see below); these indicators serve to identify, locate or delimit regions that suffer from a deficit of available water, a condition that can severely affect the effective use of the land for such ...
Desertification is a gradual process of increased soil aridity.Desertification has been defined in the text of the United Nations Convention to Combat Desertification (UNCCD) as "land degradation in arid, semi-arid and dry sub-humid regions resulting from various factors, including climatic variations and human activities."
Semi-arid lands; Arid lands; Hyper-arid lands; Some authorities regard hyper-arid lands as deserts (United Nations Convention to Combat Desertification - UNCCD) although a number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands.
Dryland farming caused a large dust storm in parts of Eastern Washington on October 4, 2009. Courtesy: NASA/GSFC, MODIS Rapid Response [1]. Dryland farming has evolved as a set of techniques and management practices to adapt to limited availability of water, as in the Western US and other regions affected by climate change for crops such as tomato and maize.
Desert farming is the practice of developing agriculture in deserts. As agriculture depends upon irrigation and water supply, farming in arid regions where water is scarce is a challenge. However, desert farming has been practiced by humans for thousands of years. In the Negev, there is evidence to suggest agriculture as far back as 5000 BC. [1]
The desert climate or arid climate (in the Köppen climate classification BWh and BWk) is a dry climate sub-type in which there is a severe excess of evaporation over precipitation. The typically bald, rocky, or sandy surfaces in desert climates are dry and hold little moisture, quickly evaporating the already little rainfall they receive.