The difference between the current amount of soil moisture and the moisture which would be in that soil at field capacity. …
A vertical section through a soil, which is often preserved with resin and mounted for display. …
The highest level within a soil classification. There are 11 soil orders in the Comprehensive Soil Classification System, which are alfisols, andisols, aridisols, entisols, histosols, inceptisols, mollisols, oxisols, spodsols, ultisols, and vertisols. …
A subdivision of a soil series, based on characteristics (such as slope) that affect the use and management of the soil but not enough to create a separate soil series. …
1 A drain that conveys liquid waste from toilets. 2 A natural small‐scale tunnel within a soil, usually part of a network, that plays a part in soil erosion and gully development. Also known as pipe . …
The capacity of a soil to produce a particular yield of crops or other plants, under a given specified system of management. …
The vertical arrangement of layers or horizons in a soil. See also soil horizon. …
A measure of the degree of acidity or alkalinity of a soil. See also pH …
An area across which soils are relatively uniform. There are 50 soil regions in the USA, which vary with climate and vegetation. …
A soil that has become damaged by large quantities of salts, usually from poor quality irrigation water, under conditions of poor or impaired drainage. See also salinization. …
A group of soils that have similar soil profile characteristics and are derived from similar parent materials. …
The liquid phase of the soil, which comprises the water and the solutes that are dissolved within it. …
The arrangement of soil particles into larger particles or clumps. …
The systematic examination, description, classification, and mapping of soils within an area. Also known as a soil resource inventory . …
A named group of soils which have a similar soil taxonomy. …
The relative proportion of the various size groups of individual particles (sand, silt, and clay) in a soil. …
A subdivision of a soil series defined in terms of surface soil texture. …
Water that is contained in the pore spaces of a soil, as gravitational water, capillary water, and hygroscopic water. Also known as soil moisture . …
Any natural factor that influences soil formation, the most important of which are parent material, climate, natural vegetation, living organisms, slope, and time. …
The processes by which soil formation occurs, which include leaching, eluviation, illuviation, laterization, podsolization, calcification, acidification, and salinization. …
The design and building of structures that are energy efficient in terms of solar energy, involving a combination of technologies including solar panels and photovoltaic systems. …
A means of indirectly harnessing solar energy, using panels made from a semiconductor material (usually silicon) that generate electricity when illuminated by sunlight. Solar cells can be used at any latitude, and large installations are required because of the low efficiency of the technology (currently about 15%). The energy they produce is relatively expensive. Also known as a photovoltaic cel…
A device that collects solar energy, concentrates it, and converts it to useful forms of energy. Typical systems are based on heat‐absorbing (usually black) panels containing pipes through which air or water is circulated, either by thermal convection or by a pump. The air or water is heated as it passes through the panel, and the heat is usually circulated around a building through pipes. Such …
The rate at which solar energy is received just outside the Earth's atmosphere, which is about 1360 watts per square metre (W m-2). The exact rate varies a little through time, depending on variations in the total amount of energy released by the Sun, variations in the Earth's rotation around its axis, and variations in the Earth's orbit around the Sun. …
The natural regular cycle of variation in the frequency or number of sunspots, which has a length of roughly 11 years. Also known as the sunspot cycle . See also Maunder minimum. …
Energy that is derived from the radiation of the Sun, which is a sustainable, renewable, non‐polluting, and relatively reliable energy source. Nearly all the energy we use is ultimately solar, except perhaps for tidal energy (which is generated mainly by the gravitational pull of the Moon) and nuclear energy. Fossil fuels and biomass fuels are ultimately derived from solar energy. Hydropower and…
A bright eruption of hot gas in the Sun's outer atmosphere, usually associated with active groups of sunspots. …
The use of solar energy or sunlight to heat buildings. Traditional approaches to heating buildings have relied heavily on passive solar heating, particularly in sunny places. More recently, technologies have been developed to pump heat around buildings, using active solar heating or passive solar heating. There is great scope for expanding the use of solar heating systems because the energy supply…
A measure of the brightness of the Sun, which is determined by the amount of solar radiation it is emitting. …
Energy that comes from the Sun in the form of electromagnetic radiation, mostly at wavelengths of between 1.0 and 0.1 micrometres. Very shortwave (high‐energy) gamma and X‐rays are absorbed in the upper atmosphere and none reaches the surface. Much of the radiation within the ultraviolet (UV) range (0.2?0.4 micrometres) is filtered by atmospheric gases, particularly at wavelengths below 0.29 m…
The collection of celestial bodies that orbit around the Sun. …
A range of technologies that are similar in concept to solar heating technologies in using sunlight to generate heat, but they create enough heat to power a generator, which is then used to produce electricity. …
The steady stream of charged particles (mostly hydrogen and helium) that flows away from the Sun out into the solar system at all times. The solar wind creates auroras and geomagnetic storms when it interacts with the Earth's upper atmosphere. …
The time it takes the Earth to make one orbit around the Sun, which is roughly 365.24 days. …
A metallic compound of tin and lead that is used to seal joints between pipes. …
A volcano that no longer erupts lava and volcanic ash, but releases steam and gases from small vents. The steam might be exploited for geothermal energy. …
The conversion of a liquid into a solid, either naturally (such as the freezing of water into ice) or by adding material (like cement) to a liquid waste stream to make it more solid and less soluble. Also known as chemical fixation . …
Solid materials which are discarded from industrial, commercial, mining, or agricultural operations, and from community activities. Also known as garbage, refuse, or rubbish . …
The placement of solid waste that is not salvaged or recycled into its permanent, final location, such as a landfill. …
US legislation on waste disposal that provided states with money for research on the disposal of solid wastes. It was replaced by the Resource Conservation and Recovery Act (RCRA) (1976). …
The systematic collection, source separation, storage, transportation, transfer, processing, treatment, and disposal of solid waste. …
A type of soil creep that occurs in areas underlain by permafrost, under periglacial conditions. …
Living alone, not in colonies. Contrast gregarious. …
A type of grasslandsoil that is found in a subhumid or semi‐arid climate, under grass and shrub vegetation. …
The day when the Sun at mid‐day is either highest or lowest in the sky, which determines the seasons. In the northern hemisphere the Sun is highest in the sky when it is over the Tropic of Cancer on 22 June , and this defines the summer solstice; the Sun is lowest in the sky when it is over the Tropic of Capricorn on 22 December , which defines the winter solstice. The solstices, and thus the …
The ability of a substance to dissolve into another. See also gas solubility. …
That part of the soil that is capable of supporting life, which is mainly the A‐horizon and B‐horizon within a soil profile. …
A substance that can be dissolved into another substance (a solvent). …
A mixture of one or more solutes dissolved in a solvent. …
The sediment that is carried in solution by a river. Also known as dissolved load, dissolved solids, or solute load . …
A substance that has the ability to dissolve another (a solute). See also universal solvent. …
The entire body of an organism, excluding the germ cells. …
Relating to or characteristic of the body (soma). …
Damage that is caused to the chromosomes in individual body tissue cells (such as skin cells or lung cells) by environmental factors (for example, UV light in the case of skin cells and tobacco smoke/air pollution or radiation from radon decay products in lung cells), which can accumulate over successive cell divisions and lead to cancer. Contrast genetic damage. …
A device for detecting and locating objects by means of sound waves which are sent out and reflected back by the objects. Short for ?sound navigation and ranging?. See also sodar. …
A loud explosion‐like sound in the air that is caused by a shock wave from an aircraft (or any object) travelling at or above the speed of sound. …
One of the largest and hottest deserts in North America, which straddles part of the border between the USA and Mexico and covers large parts of the states of Arizona, California, and Sonora. It has a dry, clear climate and contains some unique plants and animals, such as the saguaro cactus. …
Fine carbon dust that is formed by the incomplete combustion of fossil fuels, and gives smoke its colour. …
The action of soaking up (absorption) or attracting (adsorption) substances, which is used in many pollution control systems. …
1 A measure of the depth of water. 2 A plot of variation in height of one or more atmospheric parameters (such as temperature, humidity, pressure, or wind speed) at a particular point in time, usually based on data from a radiosonde. …
The full range of noises that are heard in a particular place or area. …
Timber that is in a good condition, free from damage, decay, or defects. …
Any area (such as a city), place (such as a power plant), or object (such as a chimney stack) from which particular pollutants are released, or at which waste materials are produced. Contrast sink. …
A habitat that is a net exporter of individuals. Contrast sink habitat. …
A population that occupies a source habitat. Contrast sink population. …
The elimination or reduction of waste material at the source, by modifying the process which produces the waste. See also backyard composting, integrated waste management. …
A region where air masses originate and acquire their properties (particularly temperature and moisture). …
Segregating waste materials where they are generated, such as separating paper, metal, and glass from other wastes in order to make recycling simpler, more efficient, and more cost‐effective. …
Wastewater that contains containing foul‐smelling material, usually sulphur compounds. …
1 The compass point that is at 180? from north. 2 A general term (?the South?) for the less developed countries that are located in the southern hemisphere and are often referred to as the Third World. …
The half of the Earth that lies south of the equator. Contrast northern hemisphere. …
The area of ocean that lies within the Antarctic Convergence. …
A periodic reversal of the pattern of atmospheric pressure across the tropical parts of the Pacific Ocean during El Ni?o events, which occurs on average every 2.3 years, and is accompanied by variations in wind speed, ocean currents, sea‐surface temperatures, and precipitation in the surrounding areas. See also ENSO. …
A coniferous forest biome in the USA that is characterized by a warm, moist climate. …
The most southerly point on Earth, at 90?S latitude in the southern hemisphere; the southern end of the Earth's rotational axis. Contrast North Pole. See also Antarctica. …
The exercise by a state of absolute power over its territory, system of government, and population. …
1 An empty area or the distance between two or more objects. 2 The area in which the solar system, stars, and galaxies exist. …
The metaphor of the Earth as a spaceship, travelling through space as a self‐contained system, dependent on its own vulnerable supplies of natural resources (including air, water, and soil). There are some interesting implications of the Spaceship Earth metaphor. For example: spaceships are self‐contained, and as such must carry all the resources they require; spaceships are small relative to …
The arrangement of individuals in a particular area or space. …
The eggs of certain aquaticorganisms (particularly fish and amphibians), or the act of producing such eggs or egg masses. …
See Spill Prevention, Control and Countermeasure. …
An area within the European Union that is designated for protection under the Habitats Directive, because of its natural habitats and/or populations of species. See also Natura 2000. …
A large group of people who share a common cause, interest, or issue, which uses its organizational power to promote change which is beneficial to its members. See also pressure group. …
A species that has a very narrow range in terms of habitat or food requirements. Contrast generalist. …
An area within the European Union that has been designated for protection because it contain important populations of birds and habitats for birds. See also Natura 2000. …
A group of people (such as children or the elderly) which is at high risk because of its sensitivity or exposure to one or more particular hazards. …
Items of solid waste, such as household hazardous waste, bulky wastes (including refrigerators and furniture), tyres, and used oil. …
The process by which new species originate through mutation, natural selection, and evolution, dividing one species into two, which at least in theory are unable to interbreed. Rapid speciation is known as adaptive radiation. Contrast extinction. …
A population of organisms that reproduce with one another but not with other populations. This preserves the identity of the individual species through time, and it raises questions about how new species can evolve from existing ones. Species are defined in various ways, including the biological species concept, cladistic species concept, ecological species concept, phenetic species concept, and r…
An international project that was set up to index all of the known species of organisms (animals, plants, fungi, and micro‐organisms) on Earth, in order to provide a baseline dataset for comparative studies of global biodiversity. …
A measure of the total number of individuals of a particular species in a defined area, population, or community. Contrast species richness. …
A special part of a biodiversity action plan, which sets objectives and targets for the maintenance or enhancement of the population and range of particular species, and the actions necessary to achieve them, over a period of 10?15 years. See also Local Biodiversity Action Plan. …
Species whose future is at risk, either globally or within a particular region. The IUCN classification defines species in terms of the degree of threat they face, as extinct, possibly extinct, endangered, vulnerable, rare, no longer threatened, and status unknown. …
The types and number of species that occupy a particular area. …
The basis on which a species is defined. See also biological species concept, cladistic species concept, ecological species concept, phenetic species concept, recognition species concept. …
The number and relative abundance of species that are present in a particular community. See also biodiversity. …
The ratio between the total number of species in a particular community, and some measure of the relative importance of individual species (for example, in terms of number, biomass, or productivity). See also Shannon?Wiener index. …
A North American term for a native species that is not listed as endangered or threatened but whose population is declining fast enough to cause concern among biologists. …
A plan that is designed to halt the decline of an endangered species, and increase its population, through protection, habitat management, captive breeding, disease control, or other techniques. …
The number of species that are present in a habitat or ecosystem. Also known as alpha diversity . …
Within the UK Biodiversity Action Plan, an overview of the status of species and broad policies developed to conserve them. …
A captive breeding programme, usually within a zoo or aquarium, that is designed to aid the recovery of a particular species by breeding a healthy, genetically diverse, and self‐sustaining captive population. …
In island biogeography, the relationship between the area of the island and the number of species that occur within it; as area increases, the number of species present (diversity) usually also increases. …
A measure of the conductivity of a sample of water (its ability to conduct an electrical current), which reflects its content of dissolved solids. …
The relative weight of a mineral compared with the weight of an equal volume of pure water, which has a specific gravity of one. …
The amount of heat that is required to raise the temperature of one gram of a substance by 1?C. See also heat capacity. …
The mass of water vapour in a given mass of air, usually expressed as grams per kilogram (g kg-1): a measure of humidity. …
The amount of water that a unit volume of saturatedpermeable rock will yield when drained by gravity. …
An individual, item, or part that is considered typical of a group, class, or whole. …
The distribution of electromagnetic radiation in order of wavelength. See also electromagnetic spectrum. …
Nuclear fuel from a commercial reactor that is no longer capable of sustaining the fission process. See also nuclear fuel cycle, reprocessing. …
The deliberate release of water from a dam, through the spillway. See also oil spill. …
A North American plan that outlines how a facility will prevent oil spills, and how it plans to control and contain an oil spill to keep it from reaching surface water. …
The overflow structure of a dam, through which excess or flood flows are released. …
A low ridge or bar of sand and gravel that projects from the shore into the sea, and is formed by the deposition of sediment moved along the coast by longshore drift. …
The B‐horizon in a spodosol, in which aluminium and organic matter accumulate. …
A soil order in the Comprehensive Soil Classification System, comprising sandy soils that develop under forests (particularly coniferous forest), are acidic, and have accumulations of organic matter and iron oxides and aluminium oxides in the B‐horizon. …
The overburden of rock and soil that is removed to gain access to the coal or mineral material in surface mining. …
A mound of mine refuse that is created by the deposit of overburden or waste rock. Also known as spoil heap . …
The microscopic seed‐like cells of fungi that grow directly into a new plant. …
A vehicle that has the load‐hauling and passenger‐carrying capacity of a large station wagon or minivan, which may or may not be suitable for off‐road driving. …
Syst?me Probatoire d'Observation de la Terre, a satelliteremote sensing system which was launched in 1986 and provides information on a commercial basis for environmental research and monitoring, ecology management, and for use by the media, environmentalists, and legislators. …
A special type of land use zoning that allows particular activities in an isolated plot of land which would not be allowed in the surrounding area. …
Low density development on the edge of cities and towns, which is usually poorly planned, occupies much land, and depends heavily on vehicles. See also suburban sprawl. …
The application of a liquid (such as a fertilizer, herbicide, or insecticide) in the form of small particles which are ejected from a sprayer. …
To extend, scatter, or disperse, for example to expand the geographical distribution of an organism within a particular area. …
The area around a mid‐ocean ridge, under the sea, where newly formed crust is moving away from the central axis of the ridge, at rates of 1?10 centimetres per year. …
1 A place where groundwater flows naturally from the water table in rock onto the land surface. 2 The season of growth, between winter and summer, when temperatures at mid‐latitudes increase as the Sun approaches the summer solstice. Astronomically this is the period between the vernal equinox and the summer solstice, which covers the months of March, April, and May in the northern hemisphere, a…
A line of springs, usually defined by changes in rock type. …
A tide which occurs about every two weeks and coincides with the new and full moon, which has a large tidal range because the gravitational forces of the Moon and Sun complement each other. Contrast neap tide. …
A method of irrigation that uses mechanical devices that sprinkle water over crops to simulate rain. …
A sudden, violent wind that is often accompanied by rain. …
A line of thunderstorms or squalls that may extend over several hundred kilometres. …
Someone who settles upon land without permission or authority. …
A shanty town that occupies land without the owner's permission. …
1 A condition of the atmosphere that exists when the dry adiabatic lapse rate is greater than the normal lapse rate, so that a parcel of air that is caused to rise will tend to sink back to its original height without cooling to the dew point, so no condensation occurs. 2 The propensity of a system to attain a steady state or stable oscillation. See also persistence, resilience, sensitivity. …
The process that is used to convert harmful bacteria and odours in sludge into inert, harmless material, which usually involves aerobic or anaerobicdigestion. …
Air that has little or no tendency to rise, which is usually accompanied by clear dry weather. See also stability. …
A system that tends to return to the same equilibrium after disturbance. …
An atom whose nucleus is not radioactive and therefore does not alter (decay) through time. …
1 A large, tall chimney through which combustion gases and smoke are released into the air. Also known as a smokestack . 2 An isolated pillar of rock in the sea, the remnant of a former cliff that has been eroded by wave attack. …
An upward flow of air in a building that is caused by warm air rising, which creates positive pressure at the top of a building and negative pressure at the bottom. It can disrupt ventilation and air circulation within the building. …
A brief period of glacial advance (glaciation) within a glacial stage. Contrast interstade. …
A cold period, within a generally warmer climate, which is too short‐lived for an ice sheet or glacier to fully form. …
The level of the water surface relative to a given datum, at a given location, such as in a stream channel. …
Not in a current or stream, and thus still rather than moving or flowing. …
A person or group who have a vested interest in a particular project, activity, or issue because they are involved in it or affected by it. …
An analysis of the interests of different stakeholders in a project, activity, or issue, such as a conservation project. …
A group of similar plants in a particular area. See also timber stand. …
A basis for comparison, such as the maximum concentration of a particular air pollutant or effluent that is adopted by a regulatory authority as enforceable. …
A hypothetical vertical distribution of temperature, pressure, and density of air in the atmosphere which, by international consent, is regarded as representative of the overall atmosphere, for example for use in designing missiles and aircraft.? …
The ratio of the number of deaths in a population to the expected number of deaths in a standard population adjusted for age and possibly other factors such as gender or race. …
An urban region in the USA that has at least 100?000 inhabitants, and has strong economic and social ties to a central city of at least 50?000 people. …
The level of material well‐being of an individual or group, in terms of goods and services available to them. A measure of quality of life. …
The degree of crowding of trees in a stand or a forest, often expressed as the number of trees per unit area. …
The total amount of biomass in an ecosystem at a particular point in time, usually expressed as the weight (in grams) of living material per unit area or volume. …
A complex carbohydrate that is found mainly in the seeds, fruits, roots, and other parts of plants, particularly in corn, potatoes, wheat, and rice. …
The first specified future date when the forward contractemissions reductions will be delivered under the Kyoto Protocol. …
The price of the emissions reductions at the starting delivery date in the bid or offer for a forward contract, under the Kyoto Protocol. …
The presence of very strong colours in a species. Contrast camouflage, disruptive coloration. …
A state of extreme hunger that results from lack of essential nutrients over a prolonged period of time. …
A period of little or no detectable change, for example in the evolution of a species. …
A detailed description of the programmes a state in the USA will use to carry out its responsibilities under the Clean Air Act, which must be approved by the Environmental Protection Agency. …
Land that is owned and administered by the state in which it is located. …
The informal name of a non‐legally binding framework for international action in dealing with the causes and impacts of deforestation, particularly within the tropics, that was agreed at the United Nations Conference on Environment and Development in 1992 . Its formal title is Non‐Legally Binding Authoritative Statement of Principles for a Global Consensus on the Management, Conservation and …
One of the three normal states of matter, which are solid, liquid, and gas. …
A report that provides up‐to‐date information relating to environmental quality and natural resources, which usually includes an inventory of what is there, an assessment of their state and quality, a baseline against which to compare changes, and the prospect of monitoring of changes through time. …
A park or recreation area in the USA that is owned and administered by the state in which it is located. …
A type of equilibrium that occurs where force and reaction are balanced, and the properties of the system remain unchanged over time. Contrast steady‐state equilibrium. …
A front between warm and cold air masses, which is moving very slowly or not at all. …
A source of pollution (such as a smokestack) that does not move. Contrast mobile source. …
A measure that is calculated from a sample of data. …
The difference between the upper and lower values in a set of data. …
A branch of mathematics that deals with the collection, analysis, interpretation, and presentation of large amounts of numerical data. …
An unknown category of species that is defined by the IUCN *Red Data Book as ?no information is available with which to assign a conservation category?. …
An act that is passed by a legislative branch of government, which declares, commands, or prohibits something, and which describes law and defines the time within which parties must take action to comply. …
A government body which has powers defined in law, such as the Environment Agency in the UK and the Environmental Protection Agency in the USA. …
Law which is enacted by the legislative branch of government, in contrast to case law or common law …
A state in which the properties of a system remain constant and there are no net exchanges of mass or energy with the surrounding environment over time. Also known as equilibrium state . See also homeostasis. …
An economy in which birth and death rates are relatively low, and the use of renewable energy sources and recycling of materials is relatively constant over time. …
A type of equilibrium in which the average condition of the system remains unchanged over time. Contrast static equilibrium. …
An equation that can be used to calculate the black body temperature of a body (including a planet, such as the Earth). …
A bright electric discharge that is projected from objects when they are in a strong electric field, such as during a thunderstorm. …
The upright structure (stalk) that supports a plant or fungus, usually above the ground and in a direction opposite to the roots. …
The water (precipitation after interception) that trickles down the stems of plants and eventually reaches the ground below the vegetation as part of the throughfall. …
A prefix denoting the ability of an organism to tolerate only a narrow range of changes in environmental conditions. Contrast eury‐. …
An extensive, mid‐latitude, temperate, grassland biome that covers much of Eurasia, particularly Russia. …
An approach to fly pest control, which is based on releasing sterile males with which females mate only once, producing eggs that do not hatch. …
The removal or destruction of all micro‐organisms, using heat, irradiation, gas, or chemicals. Also known as disinfection . …
Responsibility for the sustainable management and use of a particular resource or place. See also land ethic. …
A process or event that involves a random variable or behaviour, or a pattern that results from random effects, but with some direction. Contrast deterministic. …
1 Farm animals that are bred and kept for meat or milk. See also livestock. 2 A plant or stem onto which a graft is made. 3 A discordantintrusive igneous feature that is smaller than a batholith, with no distinct shape. Also known as boss . …
See United Nations Conference on the Human Environment. …
A statement of ?common principles to inspire and guide the peoples of the world in the preservation and enhancement of the human environment? which was agreed at the 1972 United Nations Conference on the Human Environment. …
A reserve, held in store for future use or a special purpose. …
The small openings in leaves, herbaceous stems, and fruits, through which gases and water vapour pass from the surrounding air. …
The prehistoric period of human culture in Europe that lasted up to about 2000 bc (up to the dawn of the Bronze Age), during which stone was the main material used for making tools and weapons. Archaeologists usually divide the Stone Age into four periods: the eolithic, the Palaeolithic, the Mesolithic, and the Neolithic. …
A type of patterned ground on low slopes, in which stones are moved across the ground surface by freeze‐thaw action and are aligned in the shape of polygons. Contrast stone stripe. …
A type of patterned ground on steep slopes, in which stones are moved across the ground surface by freeze‐thaw action and are aligned in stripes oriented downhill. Contrast stone polygon. …
General term for the temporary holding (for example in containers, tanks, waste piles, and surface impoundments) of waste material while it awaits treatment or disposal. …
A violent weather episode that often includes extreme conditions, such as strong winds (force 11 on the Beaufort scale), heavy rain, hail, or snow, often accompanied by thunder and lightning. …
The rapid runoff on a river hydrograph that is created directly by the input of precipitation from a storm. …
A sewer system that collects and carries rain and snow runoff to a point where it can soak back into groundwater or flow into surface waters. …
An abnormally high wall of seawater that is pushed ashore by high winds, and is normally associated with the approach of a hurricane. …
A warning that is issued about an impending storm, which involves sustained surface winds of greater than about 90 kilometres an hour. …
The portion of precipitation which flows over land into storm sewers or surface waters. …
The equipment (which includes pipes, pumps, and conduits) that is used to collect and transport surface water from precipitation, and/or wastewater, to and from storage or treatment areas. …
The side of a slope that faces the direction of flow of ice, wind, or water. Contrast lee. …
1 A genetic variant, or group of organisms within a species that differ very little from similar groups. See also cultivar. 2 Deformation of a material as a result of applied force. See also isostatic adjustment. …
