DesertificationDesertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become arid. It is the spread of arid areas caused by a variety of factors, such as climate change and overexploitation of soil as a result of human activity. Throughout geological history, the development of deserts has occurred naturally. In recent times, the potential influences of human activity, improper land management, deforestation and climate change on desertification is the subject of many scientific investigations.
SavannaA savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to Britannica, there exists four savanna forms; savanna woodland where trees and shrubs form a light canopy, tree savanna with scattered trees and shrubs, shrub savanna with distributed shrubs, and grass savanna where trees and shrubs are mostly nonexistent.
RegionIn geography, regions, otherwise referred to as areas, zones, lands or territories, are portions of the Earth's surface that are broadly divided by physical characteristics (physical geography), human impact characteristics (human geography), and the interaction of humanity and the environment (environmental geography). Geographic regions and sub-regions are mostly described by their imprecisely defined, and sometimes transitory boundaries, except in human geography, where jurisdiction areas such as national borders are defined in law.
BiomeA biome (ˈbaɪ.oʊm) is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader term than habitat and can comprise a variety of habitats. While a biome can cover small areas, a microbiome is a mix of organisms that coexist in a defined space on a much smaller scale. For example, the human microbiome is the collection of bacteria, viruses, and other microorganisms that are present on or in a human body.
Water tableThe water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated. The water table is the surface where the water pressure head is equal to the atmospheric pressure (where gauge pressure = 0). It may be visualized as the "surface" of the subsurface materials that are saturated with groundwater in a given vicinity.
Colorado RiverThe Colorado River (Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. states and two Mexican states. The name Colorado derives from the Spanish language for "colored reddish" due to its heavy silt load. Starting in the central Rocky Mountains of Colorado, it flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border.
LandformA landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great ocean basins.
AzawadAzawad, or Azawagh (Tuareg: Azawaɣ, or Azawad; أزواد), was a short-lived unrecognised state lasting from 2012 to 2013. Azawagh (Azawaɣ) is the generic Tuareg Berber name for all Tuareg Berber areas, especially the northern half of Mali and northern and western Niger. The Azawadi declaration of independence was declared unilaterally by the National Movement for the Liberation of Azawad (MNLA) in 2012, after a Tuareg rebellion drove the Malian Armed Forces from the region.
Libyan DesertThe Libyan Desert (not to be confused with the Libyan Sahara) is a geographical region filling the northeastern Sahara Desert, from eastern Libya to the Western Desert of Egypt and far northwestern Sudan. On medieval maps, its use predates today's Sahara, and parts of the Libyan Desert include the Sahara's most arid and least populated regions; this is chiefly what sets the Libyan Desert apart from the greater Sahara.
VirgaIn meteorology, a virga, also called a dry storm, is an observable streak or shaft of precipitation falling from a cloud that evaporates or sublimates before reaching the ground. A shaft of precipitation that does not evaporate before reaching the ground is a precipitation shaft. At high altitudes the precipitation falls mainly as ice crystals before melting and finally evaporating; this is often due to compressional heating, because the air pressure increases closer to the ground.
