John P. Rafferty writes about Earth processes and the environment. Program in which cities identify blighted inner-city neighborhoods, acquire the properties from private owners, relocate the residents and businesses, clear the site, build new roads and utilities, and turn the land over to private developers. Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting. Hydraulic civilization, according to the theories of the German-American historian Karl A. Wittfogel, any culture having an agricultural system that is dependent upon large-scale government-managed waterworks—productive (for irrigation) and protective (for flood control). We live in a world where climate change is often a hot topic of discussion. Desertification Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting. AP Human Geography Agriculture DRAFT. A machine that reaps, threshes, and cleans grain while moving over a field. In Asia, Iraq has lost over 70 percent of its irrigated land to salt accumulation. By definition, desertification is “the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture ”. Get exclusive access to content from our 1768 First Edition with your subscription. Desertification, also called desertization, the process by which natural or human causes reduce the biological productivity of drylands (arid and semiarid lands). Example: Slash and Burn promotes desertification Application: Desertification destroys soil and ultimately makes it useless for years(until the nutrients are replenished) Modern Diffusion. Desertification 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 increasingly arid. Groundwater is a valuable resource both in the United States and throughout the world. Land degradation is in turn defined as the reduction or loss of the biological or economic productivity of drylands. The conference explored the causes and contributing factors and also possible local and regional solutions to the phenomenon. A form of subsistence agriculture in which farmers must expend a relatively large amount of effort to produce the maximum feasible yield from a parcel of land. This report evaluates the condition of desertification in drylands, including hyper-arid areas, by asking pointed questions and providing answers based exclusively on the reports genera… The seasonal migration of livestock between mountains and lowland pastures. Omissions? Desertification. S- Armenian is the official language (Indo-European) and Russian is the second official language. Articles from Britannica Encyclopedias for elementary and high school students. Harvesting twice a year from the same field. Grazing lands, which are harmed by overgrazing, soil. 2.3 Overpopulation ... increasing desertification that encroaches into arable land, over-fishing of the oceans, mass extinction of species, air and water pollution, and anthropogenic (human-induced) climate change. Grass or other plants grown for feeding grazing animals, as well as land used for grazing. A form of subsistence agriculture based on herding domesticated animals. Desertification Desertification is the process of productive cropland turning into non-productive, desert-like environments. AP Human Geography - The First Agricultural Revolution. When used to irrigate crops, runoff evaporates and leaves behind much of the salts that it collected. Learn faster with spaced repetition. Political Geography: nations, boundaries, geopolitics, military movements, treaties, devolution, choke points, and imperialism 4. Includes score reports and progress tracking. He serves currently as the editor of Earth and life sciences, covering climatology, geology, zoology, and other topics that relate to... Young trees planted to hinder sandstorms and reverse desertification in the Xihu preservation area of the Gobi Desert, near Dunhuang, China. You often hear about temperature changes, sea level rising, and shifting climate zones. For example, since 1993, the One common form that migration takes is chain migration., Study Flashcards On AP Human Geography Chapter 3 at This process can rapidly transform productive land into relatively barren salt flats scattered with halophytes (plants adapted to high levels of salt in the soil). The United Nations Environment Programme (UNEP) notes that desertification has affected 36 million square km (14 million square miles) of land and is a major international concern. To remove chaff by allowing it to be blown away by the wind. Commercial agriculture characterized by integration of different steps in the food-processing industry, usually through ownership by large corporations. Desertification is defined by the U.N. Convention to Combat Desertification as land degradation in arid, semiarid and dry subhumid areas resulting from various factors, including climatic variations and human activities. A form of subsistence agriculture in which people shift activity from one field to another; each field is used for crops for a relatively few years and left fallow for a relatively long period. 0% average accuracy. “Desertification” is the name given to the process by which previously fertile agricultural lands are made infertile made by human practices. Such changes may be temporary, lasting only a season, or they may persist over many years and decades. Question #203253. ‘Pollution, erosion, desertification, increased rates of extinction and more can all be traced back to us.’ ‘Despite the massive amount of land claimed by expanding desertification each year, the phenomenon receives only infrequent attention, perhaps because the effects seldom seem to … 9th - 12th grade. desertification The encroachment of desert conditions on moister zones along the desert margins, where plant cover and soils are threatened by desiccation--through overuse, in part by humans and their domestic animals, and, possibly, in part because of inexorable shifts in … Husks of grain separated from the seed by threshing. Through AP courses in 38 subjects, each culminating in a … answer choices Malay word for wet rice, commonly but incorrectly used to describe a sawah. The word invokes images of sand dunes blowing over abandoned farms as some irresistible, dark force steadily transforms fertile fields into inhospitable wasteland. College Board’s Advanced Placement® Program (AP®) enables willing and academically prepared students to pursue college-level studies—with the opportunity to earn college credit, advanced placement, or both—while still in high school. 3 hours ago. Rapid diffusion of new agricultural technology, especially new high-yield seeds and fertilizers. Over 60 percent of these irrigated areas occur in drylands. System of planting crops on ridge tops, in order to reduce farm production costs and promote greater soil conservation. Reproduction of plants by direct cloning from existing plants. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. Certainly, some dryland areas have been irrigated for millennia, but other areas are more fragile. “Salinization,” which refers to the buildup of salt deposits through irrigation and evaporation, is an example of desertification. Let us know if you have suggestions to improve this article (requires login). Updates? Wheat planted in the spring and harvested in the late summer. All of these things have economic and environmental costs that we must consider. Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting. The United Nations’ official definition says desertification is land degradation in typically dry areas resulting from various factors, including climatic variations and human activities. The first major periods of agricultural diffusion were among the most dramatic changes in human history, but this doesn't mean that innovations stopped back in the Neolithic period. Declines in productivity may be the result of climate change, deforestation, overgrazing, poverty, political instability, unsustainable irrigation practices, or combinations of these factors. Irrigated crops need an average of 80 cm (about 30 inches) of water annually. our editorial process. Definition: Degradation of land, especially in semiarid areas, primarily because of human actions like excessive crop planting, animal grazing, and tree cutting. Considerable controversy exists over the proper definition of the term “desertification” for which Helmut Geist (2005) has identified more than 100 formal definitions.The most widely acceptedof these is that of the Princeton University Dictionary which defines it as “the process of fertile land transforming into desert typically as a result of deforestation, drought or improper/inappropriate agriculture” The earliest known discussion of the topic arose soon after the French colonization of West Africa, when the Comité d’Etud… Such losses are not restricted to developing countries. A large farm in tropical and subtropical climates that specializes in the production of one or two crops for sale, usually to a more developed country. 0. Quickly memorize the terms, phrases and much more. Another name for shifting cultivation, so named because fields are cleared by slashing the vegetation and burning the debris. Runoff percolates through the soil, dissolving and collecting much of the salts it encounters, before finding its way into rivers or aquifers. On the other hand, plants and animals are quick to take advantage of wetter periods, and productivity can rapidly increase during these times. Most salt-degraded cropland occurs in Asia and southwestern North America, which account for 75 and 15 percent of the worldwide total, respectively. Wittfogel advanced the Food security. stewart_massey_57994. Our editors will review what you’ve submitted and determine whether to revise the article. Commercial gardening and fruit farming, so named because truck was a Middle English word meaning bartering or exchange of commodities. The deliberate effort to modify a portion of Earth's surface through the cultivation of crops and the raising of livestock for sustenance or economic gain. Desertification, also called desertization, the process by which natural or human causes reduce the biological productivity of drylands (arid and semiarid lands). While interpretations of the term desertification vary, the concern centers on human-caused land degradation in areas with low or variable rainfall known as … By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. In contrast, water used for irrigation is the result of runoff from precipitation. Extensive human migration has a long history. The countries that lie on the edge of the Sahara are among the poorest in the world, and they are subject to periodic droughts that devastate their peoples. chain migration.. The First Agricultural Revolution was the transition of humans from nomadic hunting/gathering to sedentary agricultural production of domesticated plants and animals. Low rainfall and locusts caused a food crisis during the summer of 2005. (Oxford Dictionary) Areas that are predisposed to desertification are usually those located in warm, semi-arid or arid climates. Desalinization definition at, a free online dictionary with pronunciation, synonyms and translation. African drylands (which include the Sahara, the Kalahari, and the grasslands of East Africa) span 20 million square km (about 7.7 million square miles), some 65 percent of the continent. The concept does not refer to the physical expansion of existing deserts but rather to the various processes that threaten all dryland ecosystems, including deserts as well as grasslands and scrublands. The practice of rotating use of different fields from crop to crop each year, to avoid exhausting the soil. A machine that cuts grain standing in a field. Includes score reports and progress tracking. Essentially, rainwater is distilled seawater or lake water. Currently suffering due to the blockade along the borders and cannot get the supplies and raw materials it needs to be based on industry. Slightly less than half of Earth’s ice-free land surface—approximately 52 million square km (about 20 million square miles)—is drylands, and these drylands cover some of the world’s poorest countries. Dry woodlands, which are plagued by the overconsumption of fuelwood. The main cause of declining biological productivity in irrigated croplands is the accumulation of salts in the soil.
2020 desertification ap human geography definition