Irrigation in the context of Tule River

The Fertile Crescent (Arabic: الهلال الخصيب al-hilāl al-ḵaṣīb) is a crescent-shaped region in the Middle East, spanning modern-day Iraq, Israel, Jordan, Lebanon, Palestine, and Syria, together with northern Kuwait, south-eastern Turkey, and western Iran. Some authors also include Cyprus and northern Egypt.

The Fertile Crescent is believed to be the first region where settled farming emerged as people started the process of clearance and modification of natural vegetation to grow newly domesticated plants as crops. Early human civilizations such as Sumer in Mesopotamia flourished as a result. Technological advances in the region include the development of agriculture and the use of irrigation, of writing, the wheel, and glass, most emerging first in Mesopotamia.

Yellow River civilization, Huanghe civilization or Huanghe Valley civilization (Chinese: 黃河文明), Hwan‐huou civilization is an ancient Chinese civilization that prospered in the middle and lower basin of the Yellow River. Agriculture was started in the flood plain of the Yellow River, and before long, through flood control and the irrigation of the Yellow River, cities were developed and political power found reinforcement. One of the "four major civilizations of the ancient world", it is often included in textbooks of East Asian history, but the idea of including only the Yellow River civilization as one of the four biggest ancient civilizations has become outdated as a result of the discovery of other early cultures in China, such as the Yangtze and Liao civilizations. The area saw the Yangshao and Longshan cultures of the Neolithic era and developed into the bronze ware culture of the Shang and Zhou dynasties.

Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow under atmospheric pressure, and can be thought of as artificial rivers.

In most cases, a canal has a series of dams and locks that create reservoirs of low speed current flow. These reservoirs are referred to as slack water levels, often just called levels. A canal can be called a navigation canal when it parallels a natural river and shares part of the latter's discharges and drainage basin, and leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley.

Agricultural land is typically land devoted to agriculture, the systematic and controlled use of other forms of life—particularly the rearing of livestock and production of crops—to produce food for humans. It is generally synonymous with both farmland or cropland, as well as pasture or rangeland.

The United Nations Food and Agriculture Organization (FAO) and others following its definitions, however, also use agricultural land or agricultural area as a term of art, where it means the collection of:

Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity. One is physical. The other is economic water scarcity. Physical water scarcity is where there is not enough water to meet all demands. This includes water needed for ecosystems to function. Regions with a desert climate often face physical water scarcity. Central Asia, West Asia, and North Africa are examples of arid areas. Economic water scarcity results from a lack of investment in infrastructure or technology to draw water from rivers, aquifers, or other water sources. It also results from weak human capacity to meet water demand. Many people in sub-Saharan Africa are living with economic water scarcity.

There is enough freshwater available globally and averaged over the year to meet demand. As such, water scarcity is caused by a mismatch between when and where people need water, and when and where it is available. This can happen due to an increase in the number of people in a region, changing living conditions and diets, and expansion of irrigated agriculture. Climate change (including droughts or floods), deforestation, water pollution and wasteful use of water can also mean there is not enough water. These variations in scarcity may also be a function of prevailing economic policy and planning approaches.

Water pollution (or aquatic pollution) is the contamination of water bodies, with a negative impact on their uses. It is usually a result of human activities. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants mix with these water bodies. Contaminants can come from one of four main sources. These are sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. Water pollution may affect either surface water or groundwater. This form of pollution can lead to many problems. One is the degradation of aquatic ecosystems. Another is spreading water-borne diseases when people use polluted water for drinking or irrigation. Water pollution also reduces the ecosystem services such as drinking water provided by the water resource.

Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain, a wastewater treatment plant, or an oil spill. Non-point sources are more diffuse. An example is agricultural runoff. Pollution is the result of the cumulative effect over time. Pollution may take many forms. One would is toxic substances such as oil, metals, plastics, pesticides, persistent organic pollutants, and industrial waste products. Another is stressful conditions such as changes of pH, hypoxia or anoxia, increased temperatures, excessive turbidity, or changes of salinity). The introduction of pathogenic organisms is another. Contaminants may include organic and inorganic substances. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.

Wildlife management is the management process influencing interactions among and between wildlife, its habitats and people to achieve predefined impacts. Wildlife management can include wildlife conservation, population control, gamekeeping, wildlife contraceptive and pest control.

Wildlife management aims to halt the loss in the Earth's biodiversity, by taking into consideration ecological principles such as carrying capacity, disturbance and succession, and environmental conditions such as physical geography, pedology and hydrology. Most wildlife biologists are concerned with the conservation and improvement of habitats; although rewilding is increasingly being undertaken. Techniques can include reforestation, pest control, nitrification and denitrification, irrigation, coppicing and hedge laying.

A terrace in agriculture is a flat surface that has been cut into hills or mountains to provide areas for the cultivation for crops, as a method of more effective farming. Terrace agriculture or cultivation is when these platforms are created successively down the terrain in a pattern that resembles the steps of a staircase. As a type of landscaping, it is called terracing.

Terraced fields decrease both erosion and surface runoff, and may be used to support growing crops that require irrigation, such as rice. The Rice Terraces of the Philippine Cordilleras have been designated as a UNESCO World Heritage Site because of the significance of this technique.

The Green Revolution, or the Third Agricultural Revolution, was a period during which technology transfer initiatives resulted in a significant increase in crop yields. These changes in agriculture initially emerged in developed countries in the early 20th century and subsequently spread globally until the late 1980s. In the late 1960s, farmers began incorporating new technologies, including high-yielding varieties of cereals, particularly dwarf wheat and rice, and the widespread use of chemical fertilizers (to produce their high yields, the new seeds require far more fertilizer than traditional varieties), pesticides, and controlled irrigation.

At the same time, newer methods of cultivation, including mechanization, were adopted, often as a package of practices to replace traditional agricultural technology. This was often in conjunction with loans conditional on policy changes being made by the developing nations adopting them, such as privatizing fertilizer manufacture and distribution.

Rain is a form of precipitation where water droplets that have condensed from atmospheric water vapor fall by gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water for hydroelectric power plants, crop irrigation, and suitable conditions for many types of ecosystems.

The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts. If enough moisture and upward motion is present, precipitation falls from convective clouds (those with strong upward vertical motion) such as cumulonimbus (thunder clouds) which can organize into narrow rainbands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation which forces moist air to condense and fall out as rainfall along the sides of mountains. On the leeward side of mountains, desert climates can exist due to the dry air caused by downslope flow which causes heating and drying of the air mass. The movement of the monsoon trough, or Intertropical Convergence Zone, brings rainy seasons to savannah climes.

The history of slavery in the Muslim world was throughout the history of Islam with slaves serving in various social and economic roles, from powerful emirs to harshly treated manual laborers. Slaves were widely in labour in irrigation, mining, and animal husbandry, but most commonly as soldiers, guards, domestic workers. The use of slaves for hard physical labor early on in Muslim history led to several destructive slave revolts, the most notable being the Zanj Rebellion of 869–883. Many rulers also used slaves in the military and administration to such an extent that slaves could seize power, as did the Mamluks.

Most slaves were imported from outside the Muslim world. Slavery in the Muslim world did not have a racial foundation in principle, although this was not always the case in practice. The Arab slave trade was most active in West Asia, North Africa (Trans-Saharan slave trade), and Southeast Africa (Red Sea slave trade and Indian Ocean slave trade), and rough estimates place the number of Africans enslaved in the twelve centuries prior to the 20th century at between six million to ten million. The Ottoman slave trade came from raids into eastern and central Europe and the Caucasus connected to the Crimean slave trade, while slave traders from the Barbary Coast raided the Mediterranean coasts of Europe and as far afield as the British Isles and Iceland.

Ai-Khanoum (/aɪ ˈhɑːnjuːm/, meaning 'Lady Moon'; Uzbek: Oyxonim) is the archaeological site of a Hellenistic city in Takhar Province, Afghanistan. The city, whose original name is unknown, was likely founded by an early ruler of the Seleucid Empire and served as a military and economic centre for the rulers of the Greco-Bactrian Kingdom until its destruction c. 145 BC. Rediscovered in 1961, the ruins of the city were excavated by a French team of archaeologists until the outbreak of conflict in Afghanistan in the late 1970s.

The city was probably founded between 300 and 285 BC by an official acting on the orders of Seleucus I Nicator or his son Antiochus I Soter, the first two rulers of the Seleucid dynasty. There is a possibility that the site was known to the earlier Achaemenid Empire, who established a small fort nearby. Ai-Khanoum was originally thought to have been a foundation of Alexander the Great, perhaps as Alexandria Oxiana, but this theory is now considered unlikely. Located at the confluence of the Amu Darya (a.k.a. Oxus) and Kokcha rivers, surrounded by well-irrigated farmland, the city itself was divided between a lower town and a 60-metre-high (200 ft) acropolis. Although not situated on a major trade route, Ai-Khanoum controlled access to both mining in the Hindu Kush and strategically important choke points. Extensive fortifications, which were continually maintained and improved, surrounded the city.

Center-pivot irrigation (sometimes called central pivot irrigation), also called water-wheel and circle irrigation, is a method of crop irrigation in which equipment rotates around a pivot and crops are watered with sprinklers. A circular area centered on a pivot is irrigated, often creating a circular pattern in crops when viewed from above (sometimes referred to as crop circles, not to be confused with those formed by circular flattening of a section of a crop in a field). Most center pivots were initially water-powered, however today most are propelled by electric motors.

Center-pivot irrigation systems are beneficial due to their ability to efficiently use water and optimize a farm's yield. The systems are highly effective on large land fields.

Water resources are natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. These resources can be either freshwater from natural sources, or water produced artificially from other sources, such as from reclaimed water (wastewater) or desalinated water (seawater). 97% of the water on Earth is salt water and only three percent is fresh water; slightly over two-thirds of this is frozen in glaciers and polar ice caps. The remaining unfrozen freshwater is found mainly as groundwater, with only a small fraction present above ground or in the air. Natural sources of fresh water include frozen water, groundwater, surface water, and under river flow. People use water resources for agricultural, household, and industrial activities.

Water resources are under threat from multiple issues. There is water scarcity, water pollution, water conflict and climate change. Fresh water is in principle a renewable resource. However, the world's supply of groundwater is steadily decreasing. Groundwater depletion (or overdrafting) is occurring for example in Asia, South America and North America.

Environmental resource management or environmental management is the management of the interaction and impact of human societies on the environment. It is not, as the phrase might suggest, the management of the environment itself. Environmental resources management aims to ensure that ecosystem services are protected and maintained for future human generations, and also maintain ecosystem integrity through considering ethical, economic, and scientific (ecological) variables. Environmental resource management tries to identify factors between meeting needs and protecting resources. It is thus linked to environmental protection, resource management, sustainability, integrated landscape management, natural resource management, fisheries management, forest management, wildlife management, environmental management systems, and others.

Evapotranspiration (ET) refers to the combined processes which move water from the Earth's surface (open water and ice surfaces, bare soil and vegetation) into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpiration (evaporation that occurs through the stomata, or openings, in plant leaves). Evapotranspiration is an important part of the local water cycle and climate, and measurement of it plays a key role in water resource management and agricultural irrigation.