Abatement

Elimination or reduction of polluting or hazardous substances (such as asbestos) by either removing them completely or lessening their effect through better waste management.


Absorption

The passage of one substance into or through another e.g., an operation in which one or more soluble components of a gas mixture are dissolved in a liquid.


Accident site

The location of an unexpected occurrence, failure, or loss, either at a plant or along a transportation route, resulting in a release of hazardous materials.


Acid Deposition

A complex chemical and atmospheric phenomenon that occurs when emissions of sulfur and nitrogen compounds and other substances are transformed by chemical processes in the atmosphere, often far from the original sources, and then deposited on earth in either a wet or a dry form. The wet forms, popularly called “acid rain,” can fall as rain, snow, or fog. The dry forms are acidic gases or particulates. 


Acid Rain

Rain or other forms of precipitation that is unusually acidic.


Activated Carbon

A highly adsorbent form of carbon used to remove odors and toxic substances from liquid or gaseous emissions. In waste treatment, it is used to remove dissolved organic matter from waste water. It is also used in motor vehicle evaporative control systems.


Activated Sludge

Residue that results when primary effluent is mixed with bacteria-laden sludge and then agitated and aerated to promote biological treatment. This speeds breakdown of organic matter in raw sewage undergoing secondary wastewater treatment.


Active Ingredient

In any pesticide product, the component that kills, or otherwise controls, target pests. Pesticides are regulated primarily on the basis of active ingredients.


Acute Exposure

A single exposure to a toxic substance that results in severe biological harm or death. Acute exposures are usually characterized as lasting no longer than a day.


Acute Toxicity

The ability of a substance to cause poisonous effects resulting in severe biological harm or death soon after a single exposure or dose; also, any severe poisonous effect resulting from a single short-term exposure to a toxic substance.


Adaptation

Changes in an organism’s structure or habit that help it adjust to its surroundings.


Add-on Control Device

An air pollution control device such as a carbon adsorber or incinerator that reduces the pollution in an exhaust gas. The control device usually does not affect the process being controlled and thus is “addon” technology as opposed to a scheme to control pollution by making some alteration to the basic process.


Adsorption

1. Adhesion of molecules of gas, liquid, or dissolved solids to a surface. 

2. An advanced method of treating wastes in which activated carbon removes organic matter from     wastewater.


Advanced Wastewater Treatment

Any treatment of sewage that goes beyond the secondary or biological water treatment stage and includes the removal of nutrients such as phosphorus and nitrogen and a high percentage of suspended solids.


Aeration

A process that promotes biological degradation of organic water. The process may be passive (as when waste is exposed to air), or active (as when a mixing or bubbling device introduces the air).


Aerobic

Life or processes that require, or are not destroyed by, the presence of oxygen.


Aerobic Composting

A method of composting organic wastes using bacteria that need oxygen. This requires that the waste be exposed to air, either via turning or by forcing air through pipes that pass through the material.


Aerobic Treatment

Process by which microbes decompose complex organic compounds in the presence of oxygen and use the liberated energy for reproduction and growth. Types of aerobic processes include extended aeration, trickling filtration, and rotating biological contactors.


Aerosol

A suspension of small liquid or solid particles in gas.


Afforestation

Planting new forests on lands that have not been recently forested.

Agricultural Pollution

The liquid and solid wastes from farming, including runoff and leaching of pesticides and fertilizers; erosion and dust from plowing; animal manure and carcasses; and crop residues and debris.


Air Mass

A widespread body of air that gains certain meteorological or polluted characteristics for example, a heat inversion or smokiness while standing in one location. The characteristics can change as the air mass moves away.


Air pollution

Air pollution is the introduction of particulatesbiological molecules, or other harmful materials into Earth's atmosphere, causing diseases, allergies, death to humans, damage to other living organisms such as animals and food crops, or the natural or built environment. Air pollution may come from anthropogenic or natural sources.


Air Quality Index

It is a numerical scale that indicates the level of pollution in air.


Airborne Particulates

Total suspended particulate matter found in the atmosphere as solid particles or liquid droplets. The chemical composition of particulates varies widely, depending on location and time of year. Airborne particulates include windblown dust, emissions from industrial processes, smoke from the burning of wood and coal, and the exhaust of motor vehicles.


Algae

Simple rootless plants that grow in sunlit waters in relative proportion to the amounts of nutrients available. They can affect water quality adversely by lowering the dissolved oxygen in the water. Algae are food for fish and small aquatic animals.


Alluvium
Soil or sediments deposited by a river or other running water.

Alternative Energy

Energy that is not popularly used and is usually environmentally sound, such as solar or wind energy as opposed to fossil fuels.


Alternative Fibers

Fibers produced from non-wood sources for use in paper making.


Alternative Fuels

Transportation fuels other than gasoline or diesel includes natural gas, methanol, and electricity.


Alternative Transportation

Modes of travel other than private cars, such as walking, bicycling, rollerblading, carpooling and transit.


Ambient air

Any unconfined portion of the atmosphere: open air, surrounding air.


Anaerobic

A life or process that occurs in, or is not destroyed by, the absence of oxygen.


Anaerobic Digestion

A method of composting that does not require oxygen. This composting method produces methane. Also known as anaerobic composting.


Ancient Forest

A forest that is typically older than 200 years with large trees, dense canopies and an abundance of diverse wildlife.


Aquaculture

The controlled rearing of fish or shellfish by people or corporations who own the harvestable product, often involving the capture of the eggs or young of a species from wild sources, followed by rearing more intensively than possible in nature.


Aquifer

Underground source of water.


Area Sown more than once

This represents the areas on which crops are cultivated more than once during the agricultural year. This is obtained by deducting Net Area Sown from Total Cropped Area.


Area under Non-agricultural Uses

This includes all land occupied by buildings, roads and railways or under water, e.g. rivers and canals, and other land put to uses other than agriculture.


Ash

The noncombustible solid by products of incineration or other burning process.


Assimilation

The ability of a body of water to purify itself of pollutants.


Atmosphere

The 500 km thick layer of air surrounding the earth which supports the existence of all flora and fauna.


Atomic Energy

Energy released in nuclear reactions. When a neutron splits an atom's nucleus into smaller pieces it is called fission. When two nuclei are joined together under millions of degrees of heat it is called fusion.


Attenuation

The process by which a compound is reduced in concentration over time, through adsorption, degradation, dilution, or transformation.


Background level

An average or expected amount of a substance or radioactive material in a specific environment, or typical amounts of substances that occur naturally in an environment.


Bacteria

Microscopic living organisms that can aid in pollution control by consuming or breaking down organic matter in sewage or by similarly acting on oil spills or other water pollutants. Bacteria in soil, water, or air can cause human, animal, and plant health problems.


Baghouse Filter

Large fabric bag, usually made of glass fibers, used to eliminate intermediate and large (greater than 20 microns in diameter) particles. This device operates in a way similar to the bag of an electric vacuum cleaner, passing the air and smaller particulate matter while entrapping the larger particulates.


Bar Screen

In wastewater treatment, a device used to remove large solids.


Barren and Un-culturable Land

This includes all land covered by mountains, deserts, etc. Land which cannot be brought under cultivation except at an exorbitant cost is classified as unculturable whether such land is in isolated blocks or within cultivated holdings.


Basel Convention

An international agreement on the control of trans-boundary movements of hazardous wastes and their disposal, drawn up in March 1989 in Basel, Switzerland, with over 100 countries as signatories.


Bay

A bay is a body of water that is partly enclosed by land.


Benthic organism

A form of aquatic plant or animal life found on or near the bottom of a stream, lake, or ocean.


Bio Degradable Plastics

Degradable plastics in which the degradation process results in lower – molecular- weight fragments produced by the action of naturally occurring microorganisms such as bacteria,fungi and algae. 


Bio Element

Element required by a living organism


Bioaccumulative

Substances that are very slowly metabolized or excreted by living organisms and thus increase in concentration with in the organisms as the organisms breathe contaminated air, drink contaminated water, or eat contaminated food.


Bioassay

Using living organisms to measure the effect of a substance, factor, or condition by comparing before-and-after data; often used to mean cancer bioassays.


Biochemical oxygen demand or BOD

The quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedures for five days at 20 degrees Celsius, usually expressed as a concentration (e.g., mg/l). 


Biodegradable Material

Any organic material that can be broken down by microorganisms into simpler, more stable com-pounds. Most organic wastes (e.g., food, paper) are biodegradable.


Biodegradation

Decomposition or breakdown of a substance through the action of microorganisms (such as bacteria or fungi) or other natural physical processes (such as sunlight). 


Biodiesel

Biodiesel is registered with the Environmental Protection Agency as a pure fuel or as a fuel additive and is a legal fuel in commerce. It is typically produced through the reaction of a vegetable oil or animal fat with methanol in the presence of a catalyst to yield glycerin and biodiesel (chemically called methyl esters). It is an alternative fuel that can be used by itself or blended with petroleum diesel for use in diesel engines. Its use can result in substantial reduction of unburned hydrocarbons, carbon monoxide, and particulate matter.


Biodiversity

It refers to the variety and the variability among living organisms. These include diversity within species, between species, ecosystems etc.


Biogeography

A branch of geography that deals with the geographical distribution of animals and plants.


Biological Control

In pest control, the use of animals and organisms that eat or otherwise kill or outcompete pests.


Biological Magnification

Refers to the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into a river or lake, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals, or humans. The substances become concentrated in tissues or internal organs as they move up the chain.


Biological Oxidation

The way bacteria and microorganisms feed on and decompose complex organic materials; used in self-purification of water bodies and in activated sludge wastewater treatment.


Biological Treatment

A treatment technology that uses bacteria to consume waste and thus break down organic materials.


Biology

Biology is a natural science concerned with the study of life and living organisms including their structure, function, growth, evolution, distribution, and taxonomy. 


Biomass

All the living material in a given area; often refers to vegetation. Also called Biota.


Biomonitoring

The use of living organisms to test the suitability of effluents for discharge into receiving waters and to test the quality of such waters downstream from the discharge.


Biota

Plants and animals in an environment. Some of these plants and animals might be sources of food, clothing, or medicines for people.


Biotechnology

Techniques that use living organisms or parts of organisms to produce a variety of products from medicines to industrial enzymes to improve plants or animals or to develop microorganisms for specific uses such as removing toxics from bodies of water or for pesticides.


Block Plantation

Tree plantation in compact blocks of more than 0.1 ha on lands outside recorded forest areas.


Bluewater

Collectible water from rainfall; the water that falls on roofs and hard surfaces usually flowing into rivers and the sea and recharging the ground water. In nature the global average proportion of total rainfall that is blue water is about 40%. Blue water productivity in the garden can be increased by improving irrigation techniques, soil water storage, moderating the climate, using garden design and water-conserving plantings


Bottom Ash

Relatively coarse, noncombustible, generally toxic residue of incineration that accumulates on the grate of a furnace.


Brackish Water

A mixture of fresh and salt water.


Cadmium

A heavy metal element that accumulates in the environment.


Cancer

Any one of a group of diseases that occur when cells in the body become abnormal and grow or multiply out of control.


Canopy

The cover of branches and foliage formed by the crowns of trees.


CAP

Community Assistance Panel.


Car pooling

Giving people lifts (in car); or, share same car to same destination; to help reduce emissions and traffic.


Carbon adsorber

An add-on control device that uses activated carbon to absorb volatile organic compounds (VOCs) from a gas stream. The VOCs are later recovered from the carbon.


Carbon budget

 measure of carbon inputs and outputs for a particular activity.


Carbon credit

 A market-driven way of reducing the impact of greenhouse gas emissions; it allows an agent to benefit financially from an emission reduction. There are two forms of carbon credit, those that are part of national and international trade and those that are purchased by individuals. Internationally, to achieve Kyoto Protocol objectives, ‘caps’ (limits) on participating country’s emissions are established. To meet these limits countries, in turn, set ‘caps’ (allowances or credits: 1 convertible and transferable credit = 1 metric tonne of CO2-e emissions) for operators. Operators that meet the agreed ‘caps’ can then sell unused credits to operators who exceed ‘caps’. Operators can then choose the most cost-effective way of reducing emissions


Carbon Dioxide (CO2)

Carbon dioxide is a colorless gas with a density about 60% higher than that of air that is odorless at normally encountered concentrations. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms.


Carbon monoxide (CO)

A colorless, odorless, poisonous gas produced by incomplete fossil fuel combustion.


Carcinogen

Any substance that can cause or contribute to the production of cancer.


CAS registry number

A unique number assigned to a substance or mixture by the American Chemical Society Abstracts Service.


Catalytic Converter

An air pollution abatement device that removes pollutants from motor vehicle exhaust, either by oxidizing them into carbon dioxide and water or by reducing them to nitrogen and oxygen.


Catalytic incinerator

A control device that oxidizes volatile organic compounds (VOCs) by using a catalyst to promote the combustion process. Catalytic incinerators require lower temperatures than conventional thermal incinerators, yielding fuel and cost savings.


Cell

The basic unit by which a landfill is developed. It is the general area where incoming waste is tipped, spread, compacted, and covered.


Cells

1. In solid waste disposal, holes in which waste is dumped, compacted, and covered with layers of     dirt on a daily basis. 

2. The smallest structural part of living matter capable of functioning as an independent unit.


Central nervous system

The part of the nervous system that consists of the brain and the spinal cord.


Chemical oxygen demand (COD)

A measure of the oxygen required to oxidize all compounds in water, both organic and inorganic.


Chemical Substance

A chemical substance is a form of matter that has constant chemical composition and characteristic properties.


Chemical treatment

Any one of a variety of technologies that use chemicals or a variety of chemical processes to treat waste.


Chemocar

A special vehicle for the collection of toxic and hazardous wastes from residences, shops, and institutions.


Chlorinated hydrocarbons

A category which includes a class of persistent, broad-spectrum insecticides that linger in the environment and accumulate in the food chain. Among them are DDT, aldrin, dieldrin, heptaclor, chlordane, lindane, endrin, mirex, hexachloride, and toxaphene. Trichloroethylene (TCE), used as an industrial solvent, is also a chlorinated hydrocarbon.


Chlorinated solvent

An organic solvent containing chlorine atoms, e.g. methylene chloride and 1,1,1-trichloromethane, which is used in aerosol spray containers and in roadway paint.


Chlorination

The application of chlorine to drinking water, sewage, or industrial waste to disinfect or to oxidize undesirable compounds.


Chlorofluorocarbons (CFCs)

A family of inert, nontoxic, and easily liquefied chemicals used in refrigeration, air conditioning, packaging, and insulation or as solvents and aerosol propellants. Because CFCs are not destroyed in the lower atmosphere, they drift into the upper atmosphere, where their chlorine components destroy ozone.


Chronic toxicity

The capacity of a substance to cause long-term poisonous human health effects.


Cleaner Production

Processes designed to reduce the wastes generated by production.


Cleanup

Actions taken to deal with a release or threat of release of a hazardous substance that could affect humans, the environment, or both. The term is sometimes used interchangeably with the terms remedial action, removal action, response action or corrective action.


Coagulation

A clumping of particles in wastewater to settle out impurities; often induced by chemicals such as lime, alum and iron salts.


Coliform index

A rating of the purity of water based on a count of fecal bacteria.


Coliform organism

Microorganisms found in the intestinal tracts of humans and animals. Their presence in water indicates fecal pollution and potentially dangerous bacterial contamination by disease causing microorganisms.


Combined sewers

A sewer system that carries both sewage and storm water runoff. Normally, its entire flow goes to a waste treatment plant, but during a heavy storm the storm water volume may be so great as to cause overflows. When this happens untreated mixtures of storm water and sewage may flow into receiving waters. Storm water runoff may also carry toxic chemicals from industrial areas or streets into the sewer system.


Commingled

Mixed recyclables that are collected together after having been separated from mixed MSW.


Comminution

Mechanical shredding or pulverizing of waste used in both solid waste management and wastewater treatment.


Communal Collection

A system of collection in which individuals bring their waste directly to a central point, from which it is collected.


Compaction

Reduction of the bulk of solid waste by rolling and tamping.


Composite Liner

A liner system for a land-fill consisting of an engineered soil layer and a synthetic sheet of material.


Compost

The material resulting from com posting. Compost, also called humus, is a soil conditioner and in some instances is used as a fertilizer.


Compostable Plastics

Plastic that undergoes degradation by biological processes during composting to yield CO2,Water,inorganic compounds and biomass at a rate consistent with other known compostable materials and leave no visible,distinguishable or toxic residue.


Composting

The natural biological decomposition of organic material in the presence of air to form a humus-like material. Controlled methods of composting include mechanical mixing and aerating, ventilating the materials by dropping them through a vertical series of aerated chambers, or placing the compost in piles in the open air and mixing or turning it periodically.


Concentration

The amount of a substance present in a certain amount of soil, water, air, food, blood, hair, urine, breath, or any other media. 


Construction and demolition debris

Waste generated by construction and demolition of buildings, such as bricks, concrete, drywall, lumber, miscellaneous metal parts and sheets, packaging materials, etc.


Contaminant

A substance that is either present in an environment where it does not belong or is present at levels that might cause harmful (adverse) health effects. 


Conventional systems

Sewerage systems that have been traditionally used to collect municipal wastewater in gravity sewers and convey it to a central primary or secondary treatment plant prior to discharge to surface waters.


Cooling tower

A structure that helps remove heat from water used as a coolant, e.g., in electric power generating plants.


Corrosion

The dissolving and wearing away of metal caused by a chemical reaction that occurs between water and the pipes that the water contacts or when chemicals touching a metal surface or when two metals are in contact.


Cover material

Soil used to cover compacted solid waste in a sanitary landfill.


Cropping Intensity

It is the ratio of Net Area Sown to the Total Cropped Area.


Cubic feet per minute (cfm)

A measure of the volume of a substance flowing through air within a fixed period of time. With regard to indoor air, refers to the amount of air, in cubic feet, that is exchanged with indoor air in a minute’s time, or an air exchange rate.


Culturable Waste Land

This includes land available for cultivation, whether taken up or not taken up for cultivation once, but not cultivated during the last five years or more in succession including the current year for some reason or the other . Such land may be either fallow or covered with shrubs and jungles which are not put to any use. They may be accessible or unaccessible and may lie in isolated blocks or within cultivated holdings.


Current Fallows

This represents cropped area which is kept fallow during the current year.


Cyclone collector

A device that uses centrifugal force to pull large particles from polluted air.


Debt-for-Nature Swap

A financial transaction in which a portion of a developing nation's foreign debt is forgiven in exchange for local investments in conservation measures.


Decomposers

Consumers, mostly microbial, that change dead organic matter into minerals and heat.


Decomposition

The breakdown of matter by bacteria and fungi; changes the chemical makeup and physical appearance of materials.


Deforestation

 The conversion of forested areas to non-forest land for agriculture, urban use, development, or wasteland


Degradation

The process by which a chemical is reduced to a less complex form.


Delayed health effect

A disease or an injury that happens as a result of exposures that might have occurred in the past.


Dematerialisation

Decreasing the consumption of materials and resources while maintaining quality of life


Dense Bamboo

Area having bamboo density of 51-200 bamboo clumps per hectare is termed as dense bamboo.


Dense Forest

All lands with a forest cover having a canopy density of 40 percent and above.


Desalination

Producing potable or recyclable water by removing salts from salty or brackish water. This is done by three methods: distillation/freezing; reverse osmosis using membranes and electrodialysis; ion exchange. At present, all these methods are energy intensive.


Desert

An area that receives an average annual precipitation of less than 250 mm (9.8 in) or an area in which more water is lost than falls as precipitation.


Desertification

The degradation of land in arid, semi arid and dry sub-humid areas resulting from various climatic variations, but primarily from human activities.


Detritivore

 Detritus feeder - animals and plants that consume detritus (decomposing organic material), and in doing so contribute to decomposition and the recycling of nutrients.


Detritus

  Non-living particulate organic material (as opposed to dissolved organic material).


Developing countries

Development of a country is measured using a mix of economic factors (income per capita, GDP, degree of modern infrastructure (both physical and institutional), degree of industrialisation, proportion of economy devoted to agriculture and natural resource extraction) and social factors (life expectancy, the rate of literacy, poverty). The UN-produced Human Development Index (HDI) is a compound indicator of the above statistics. There is a strong correlation between low income and high population growth, both within and between countries. In developing countries, there is low per capita income, widespread poverty, and low capital formation. In developed countries there is continuous economic growth and a relatively high standard of living. The term is value-laden and prescriptive, as it implies a natural transition from "undeveloped" to "developed" when such transitions can instead be imposed. Although poverty and physical deprivation are clearly undesirable, it does not follow that it is therefore desirable for "undeveloped" economies to move towards affluent Western-style "developed" free market economies. The terms "industrialised" and "non-industrialised" are no different in this assumption.


Disease prevention
Measures used to prevent a disease or reduce its severity.


Ecological sustainability

 The capacity of ecosystems to maintain their essential processes and function and to retain their biological diversity without impoverishment


Emission factor

The relationship between the amount of pollution produced and the amount of raw material processed. For example, an emission factor for a blast furnace making iron would be the number of pounds of particulates per ton of raw material.


Emission standard

The maximum amount of airpolluting discharge legally allowed from a single source, mobile or stationary.


Endemic species

Unique plant or animal species found only in that location.


Energy

 

  • A property of all systems which can be turned into heat and measured in heat units.
available energy – energy with the potential to do work (exergy);
delivered energy – energy delivered to and used by a household, usually gas and electricity;
direct energy - the energy being currently used, used mostly at home (delivered energy) and for fuels used mainly for transport;
embodied energy - t the energy expended over the entire life cycle of a good or service OR the energy involved in the extraction of basic materials, processing/manufacture, transport and disposal of a product OR the energy required to provide a good or service;
geothermal energy – heat emitted from within the Earth’s crust as hot water or steam and used to generate electricity after transformation;
hydro energy – potential and kinetic energy of water used to generate electricity;
indirect energy – the energy generated in, and accounted for, by the wider economy as a consequence of an agent’s actions or demands;
kinetic energy - the energy possessed by a body because of its motion;
nuclear energy - energy released by reactions within atomic nuclei, as in nuclear fission or fusion (also called atomic energy);
operational energy – the energy used in carrying out a particular operation;
potential energy – the energy possessed by a body as a result of its position or condition e.g. coiled springs and charged batteries have potential energy;
primary energy – forms of energy obtained directly from nature, the energy in raw fuels(electricity from the grid is not primary energy), used mostly in energy statistics when compiling energy balances;
solar energy – solar radiation used for hot water production and electricity generation (does not include passive solar energy to heat and cool buildings etc.);
secondary energy – primary energies are transformed in energy conversion processes to more convenient secondary forms such as electrical energy and cleaner fuels;
stationary energy – that energy that is other than transport fuels and fugitive emissions, used mostly for production of electricity but also for manufacturing and processing and in agriculture, fisheries etc.;
tidal/ocean/wave energy– mechanical energy from water movement used to generate electricity;
useful energy – available energy used to increase system production and efficiency;
wind energy – kinetic energy of wind used for electricity generation using turbines

Energy Accounting

Measuring value by the energy input required for a good or service. A form of accounting that builds in a measure of our impact on nature (rather than being restricted to human-based items).


Energy Audit

A systematic gathering and analysis of energy use information that can be used to determine energy efficiency improvements. The Australian and New Zealand Standard AS/NZS 3598:2000 Energy Audits defines three levels of audit.


Energy Footprint

The area required to provide or absorb the waste from coal, oil, gas, fuelwood, nuclear energy and hydropower: the Fossil Fuel Footprint is the area required to sequester the emitted CO2 taking into account CO2 absorption by the sea etc.


Energy Management

A program of well-planned actions aimed at reducing energy use, recurrent energy costs, and detrimental greenhouse gas emissions.


Energy Recovery

The productive extraction of energy, usually electricity or heat, from waste or materials that would otherwise have gone to landfill.


Energy-For-Land Ratio

The amount of energy that can be produced per hectare of ecologically productive land. The units used are gigajoules per hectare and year, or GJ/ha/yr. For fossil fuel (calculated as CO2 assimilation) the ratio is 100 GJ/ha/yr.


Enhanced Greenhouse Effect

The increase in the natural greenhouse effect resulting from increases in atmospheric concentrations of greenhouse gases due to emissions from human activities.


Environment

 The external conditions, resources, stimuli etc. with which an organism interacts.


Environmental Flows

River or creek water flows that are allocated for the maintenance of the waterway ecosystems.


Environmental Indicator

Physical, chemical, biological or socio-economic measure that can be used to assess natural resources and environmental quality.


Environmental Movement

 Environmentalism are the conservation and green movements; a diverse scientific, social, and political movement. In general terms, environmentalists advocate the sustainable management of resources and stewardship of the natural environment through changes in public policy and individual behavior. In its recognition of humanity as a participant in ecosystems, the movement is centered around ecology, health, and human rights.


Epidemiology

The study of factors affecting the health and illness of populations, and serves as the foundation and logic of interventions made in the interest of public health and preventive medicine.


Erosion

Displacement of solids (sediment, soil, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down-slope movement in response to gravity or by living organisms.


Estuary

A semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea.


Estuary

Semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea.


Ethical consumerism

Buying things that are made ethically i.e. without harm to or exploitation of humans, animals or the natural environment. This generally entails favoring products and businesses that take account of the greater good in their operations.


Fallow Lands other than Current Fallows

 This includes all land which was taken up for cultivation but is temporarily out of cultivation for a period of not less than one year and not more than five years.


Farm Forestry

The practice of cultivating and managing trees in compact blocks on agriculture lands. 


Fertigate

 Apply fertiliser through an irrigation system


Fluorides

Gaseous, solid or dissolved compounds containing fluorine that result from industrial processes; excessive amounts in food can lead to fluorosis.


Fly ash

Noncombustible residual particles from the combustion process carried by flue gas.


Food Chain

A succession of organisms in an ecological community that constitutes a continuation of food energy from one organism to another as each consumes a lower member and in turn is preyed upon by a higher member.

Food web

A network of food chains or feeding relationships by which energy and nutrients are passed on from one species of living organisms to another.


Forest Area

The area recorded as a forest in the Government records. It is also referred to as 'recorded forest area'.


Forest Blank

A patch within a forest which bears few or no trees.

Forest Cover

All lands, more than one hectare in area, with a tree canopy density of more than 10 percent irrespective of ownership and legal status. Such lands may not necessarily be a recorded forest area. it also includes orchards, bamboo and palm.

Forest Inventory

The measurement of certain parameters of forests to assess the growing stand and stock and other characteristics of forests. 


Fossil fuel

Coal, oil and natural gas. A fuel that’s been made by the decomposition of fossilised plants and animals.

Freshwater

Water containing no significant amounts of salt; potable water suitable for all normal uses cf. potable water.

Fugitive emissions

Emissions not caught by a capture system.


Galaxy

A huge aggregate of stars held together by mutual gravitation.


Gastropods

A class of mollusks that includes snails and slugs.


GDP

Gross Domestic Product.


Geiger counter

An electrical device that detects the presence of certain types of radioactivity.


Generalists

Species that have broad adaptability; more likely to survive changes in habitat.


Generator

A facility or mobile source that emits pollutants into the air or releases hazardous wastes into water or soil.


Genetic Diversity

Variability in genetic or hereditary makeup among individuals within a single species. 


Geographical Area

 The latest figures of geographical area of the State/Union Territories are those provided by the Office of the Surveyor General of India.


Grafting

Joining one plant segment (the scion) to another (the stock: a root or an entire plant) so they grow together.


Granular activated carbon (GAC) treatment

A filtering system often used in small water systems and individual homes to remove organics. GAC can be highly effective in removing elevated levels of radon from water.


Grazer

A herbivore that feeds upon grasses.


Green Architecture

Building design that moves towards self-sufficiency sustainability by adopting circular metabolism.


Green Design

Environmentally sustainable design.


Green Power

 Electricity generated from clean, renewable energy sources (such as solar, wind, biomass and hydro power) and supplied through the grid.


Green Products

Products or services that have a lesser or reduced effect on human health and the environment when compared with competing products or services that serve the same purpose. Green products or services may include, but are not limited to, those which contain recycled content, reduce waste, conserve energy or water, use less packaging, and reduce the amount of toxics disposed or consumed.


Green Purchasing

Purchasing goods and services that minimise impacts on the environment and that are socially just.


Green Waste

Green organic material or green organics, sometimes referred to as "green wealth" plant material discarded as nonputrescible waste includes tree and shrub cuttings and prunings, grass clippings, leaves, natural (untreated) timber waste and weeds (noxious or otherwise).


Greenhouse Effect

The insulating effect of atmospheric greenhouse gases (e.g., water vapor, carbon dioxide, methane, etc.) that keeps the Earth's temperature about 60 °F (16 °C) warmer than it would be otherwise .


Greenhouse Gases

Greenhouse Gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth. In order, the most abundant greenhouse gases in Earth's atmosphere are:

  • Water vapor (H
    2
    O
    )
  • Carbon dioxide (CO2)
  • Methane (CH
    4
    )
  • Nitrous oxide (N
    2
    O
    )
  • Ozone (O
    3
    )
  • Chlorofluorocarbons (CFCs)


Gross Primary Production

The total amount of energy and nutrients transformed by plants into biomass or chemical energy.


Groundwater

Water beneath the earth's surface in the spaces between soil particles and between rock surfaces.


Groundwater

The supply of fresh water found beneath the Earth’s surface (usually in aquifers), which is often used for supplying wells and springs. Because groundwater is a major source of drinking water, there is growing concern about areas where leaching agricultural or industrial pollutants or substances from leaking underground storage tanks are contaminating it.


Guild

A group of species that fill similar ecological niches. 


Habitat

 An ecological or environmental area that is inhabited by a particular species.


Hard waste

 Household garbage which is not normally accepted into rubbish bins by local councils, e.g. old stoves, mattresses.


Hazardous waste

Potentially harmful substances that have been released or discarded into the environment. 


HDPE

High Density Poly Ethylene


Heat

 Energy derived from the motion of molecules; a form of energy into which all other forms of energy may be degraded.


Heavy metals

Metallic elements with atomic number greater than 20, such as mercury and lead. They can damage living things at low concentrations and tend to accumulate in the food chain.


Herbicide

 A chemical the kills or inhibits growth of a plant.


Hill District

A district with more than 50 percent of its geographic area under 'hill talukas' based on criteria adopted by the Planning Commission for Hill Are and Western Ghats Development programmes.


HIPS

High Impact Poly Styrene


Holding pond

A pond or reservoir usually made of earth, built to store polluted runoff.


Homoclime

A region with the same climate as the one under investigation.


Horton overland flow

The tendency of water to flow horizontally across land surfaces when rainfall has exceeded infiltration capacity and depression storage capacity.


House energy

rating - An assessment of the energy efficiency of residential house or unit designs using a 5 star scale.


Household metabolism

The passage of food, energy, water, goods, and waste through the household unit in a similar way to the metabolic activity of an organism cf. industrial metabolism.


Hydrocarbons (HC)

Chemical compounds that consist entirely of carbon and hydrogen.


Hydrogen sulfide (HS)

Gas emitted during organic decomposition and as a by-product of oil refining and burning. It smells like rotten eggs and in heavy concentration, can cause illness.


Important Bird Area (IBA)

Sites of importance to birds, identified by Birdlife International and International Waterfowl and Wetlands Research Bureau. The sites are identified for four groups of birds: regularly occurring migratory species which concentrate at and are dependent on particular sites either when breeding, or migration, or during the winter; globally threatened species (i.e species at risk of total extinction); species and sub-species threatened throughout all or parts of their range but not globally; species that have relatively small total world ranges with important populations in specific areas.

Inbreeding

Mating of close relatives resulting in increased genetic uniformity in the offspring.

Indicator species

A species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem.


Industrial agriculture

  A form of modern farming that involves industrialized production of livestock, poultry, fish, and crops.


Industrial Revolution

A period in the late 18th and early 19th centuries when major changes in agriculture, manufacturing, and transportation had a profound effect on socioeconomic and cultural conditions.


Inheritance

The features of an organism are determined by a set of chromosomes.  These originate in the parents and are passed on to an offspring during fertilization. It follows then that since chromosomes are inherited, all the features of an organism must be inherited.


Inoculants

Dominant microorganisms which may be added to a compost pile. Generally, these are not necessary as there are microorganisms living on all organic matter, so your pile already has these in it.


Insecticide

A chemical substance used to kill insects.


In-situ

Maintenance or study of organisms within an organism's native environment.

In-situ conservation

The conservation of biodiversity within the evolutionary dynamic ecosystems of the original habitat or natural environment.


Integrated Pest Management (IPM)

Using the best features of chemical, biological and cultural controls to reduce reliance on synthetic pesticides. It may include use of natural predators, chemical agents and crop rotations.


Integrated pest management (IPM)

Combined use of biological, chemical, and cultivation methods in proper sequence and timing to keep the size of a pest population below the size that causes economically unacceptable loss of a crop or livestock animal.


Intellectual Property Rights (IPR)

 Rights enabling an inventor to exclude imitators from the market for a certain period of time.


Intensive agriculture

A system of maximum output of agricultural land through use of chemicals and machinery.


Intercropping

System of growing two or more crops on the same peace of land in rows simultaneously.


Intraspecific competition

Two or individual organisms of a single species trying to use the same limited resources in an ecosystem.


Intrinsic value

The value of creatures and plants independent of human recognition and estimation of their worth.


Invasive species

Invasive species are those that are introduced-intentionally or unintentionally-to an ecosystem in which they do not naturally appear and which threaten habitats, ecosystems, or native species. These species become invasive due to their high reproduction rates and by competing with and displacing native species, that naturally appear in that ecosystem.


Inventory

On-site collection of data on natural resources and their properties.


Island biogeography

The study of the relationship between island area and species number. This idea has also been applied to isolated areas of habitat in continental areas which are effectively islands for many species. The extent to which habitat fragmentation may lead to extinction of species can be predicted from the relationship between number of species and island area.


kerbside collection

Collection of household recyclable materials (separated or co-mingled) that are left at the kerbside for collection by local council services.


keystone species

 A species that has a disproportionate effect on its environment relative to its abundance, affecting many other organisms in an ecosystem and help in determine the types and numbers of various others species in a community.


Kyoto Protocol

 An international agreement adopted in December 1997 in Kyoto, Japan. The Protocol sets binding emission targets for developed countries that would reduce their emissions on average 5.2 percent below 1990 levels.


Land under Miscellaneous Tree Crops, etc.

 This includes all cultivable land which is not included in ‘Net area sown’ but is put to some agricultural uses. Land under casuring trees, thatching grasses, bamboo bushes and other groves for fuel, etc. which are not included under ‘Orchards’ are classified under this category.


Land use

Land-use change and forestry (LULUCF) - land uses and land-use changes can act either as sinks or as emission sources. It is estimated that approximately one-fifth of global emissions result from LULUCF activities. The Kyoto Protocol allows parties to receive emissions credit for certain LULUCF activities that reduce net emissions.


Land use planning

A branch of public policy which encompasses various disciplines which seek to order and regulate the use of land in an efficient and ethical way.


Landfil

Solid waste disposal in which refuse is buried between layers of soil, a method often used to reclaim low-lying ground; the word is sometimes used as a noun to refer to the waste itself.


Landfill

(dump or tip and historically as a midden) - a site for the disposal of waste materials by burial and is the oldest form of waste treatment.


Landfill gas

The gas emissions from biodegrading waste in landfill, including CO2, CH4, and small amounts of nitrogen, oxygen with traces of toluene, benzene and vinyl chloride.


Landfill levy

Levy applied at differential rates to municipal, commercial and industrial and prescribed wastes disposed to licensed landfills the levies used to foster the environmentally sustainable use of resources and best practice in waste management.


Landfill prohibition

 The banning of a certain material or product type from disposal to landfills. Occurs occasionally, for example, where a preferable waste management option is available.


LDPE

Low Density Poly Ethylene


Leachate

(waste) - the mixture of water and dissolved solids (possibly toxic) that accumulates as water passes through waste and collects at the bottom of a landfill site.


Leaching

The movement of chemical in the upper layers of soil into lower layers or into groundwater by being dissolved in water.


Leaf area index

 (LAI) – the ratio of photosynthetic leaf area to ground area covered (optimal for photosynthesis = 3-5). LAI is often optimised by shifts in leaf angle, a form of solar tracking.


Life cycle

All stages of a product's development, from raw materials, manufacturing through to consumption and ultimate disposal.


Life Cycle Analysis

 (LCA) - an objective process to evaluate the environmental impacts associated with a product, process, or activity. A means of identifying resource use and waste released to the environment, and to assess management options.


Life support systems

According to the World Conservation Union (IUCN), the biophysical processes "that sustain the productivity, adaptability and capacity for renewal of lands, waters, and / or the biosphere as a whole."


Lilacwater

Recycled water that is unsuitable for drinking.


Linear low-density polyethylene

Amember of the polyolefin family of plastics. It is a strong and flexible plastic and usually used in film for packaging, bags and for industrial products such as pressure pipe.


Linear metabolism

 Direct conversion of resources into wastes that are often sent directly to landfill


Lithosphere

 The solid outermost shell of a rocky planet.considered ideal for gardening and agricultural uses.


LLDPE

Linear Low Density Poly Ethylene 


Loam

A soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively), *locally existing capacity - the total ecological production that is found within a country’s territories. It is usually expressed in hectares based on world average productivity.


Low entropy energy

To high-quality energy, or energy that is concentrated and available. Electricity is considered the energy carrier with the lowest entropy (i.e. highest quality) as it can be transformed into mechanical energy at efficiency rates well above 90%. In contrast, fossil fuel chemical energy can only be converted into mechanical energy at a typical efficiency rate of 25% (cars) to 50 percent (modern power plants). The chemical energy of biomass is of lower quality.


Mangrove Cover

Area covered under mangrove vegetation as interpreted from remote sensing data. It is included in the forest cover.


Mangroves

Salt tolerant evergreen forest ecosystem found mainly in tropical and sub-tropical coastal and/or inter-tidal regions.

Metabolism

The conversion or breakdown of a substance from one form to another by a living organism.


Migration

Moving from one location to another. 


Moderately Dense Forest

All lands with forest cover having a canopy density between 40 to 70%.

Native species (or Indigenous species)
A species that occurs naturally in a given region or ecosystem.

Net Area Sown

 This represents the total area sown with crops and orchards. Area sown more than once in the same year is counted only once.


Net Change (in Forest Cover))

The sum of positive and negative changes in forest cover over a period of two assessment for a given area.


Non Forest Land

Land without forest cover.

Non-point-source pollution

Pollution that enters water through run-off from farmland, forestland, and urban areas. It cannot be determined exactly where this pollution comes from.

Nymph

A larval phase of an aquatic insect.

Open Forest

Lands with forest cover having a canopy density between 10 to 40 %.

Permanent Pasture and other Grazing Land

 This includes all grazing land whether it is permanent pasture and meadows or not. Village common grazing land is included under this heading.


Physiographic Zone

A physiographic  zone constitutes geographical areas that exhibit broad similarities in Factors like physiography, climate, vegetations responsible for the growth of tree vegetation. 

Population

A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age).


PPM

Parts per million.


Protected Forest

An area notified under the provisions of the India Forest Act or other State Forest Acts, having limited degree of protection. In protect forest all activities are permitted unless prohibited. 


Pure Bamboo

Are having bamboo density of 200 or more bamboo clumps per hectare is termed as pure bamboo. 


Radiative forcing

Changes in the energy balance of the earth-atmosphere system in response to a change in factors such as greenhouse gases, land-use change, or solar radiation. Positive radiative forcing increases the temperature of the lower atmosphere, which in turn increases temperatures at the Earth's surface. Negative radiative forcing cools the lower atmosphere. Radiative forcing is most commonly measured in units of watts per square meter (W/m2).


Rain garden

An engineered area for the collection, infiltration and evapotranspiration of rainwater runoff, mostly from impervious surfaces; it reduces rain runoff by allowing stormwater to soak into the ground (as opposed to flowing into storm drains and surface waters which can cause erosion, water pollution, flooding, and diminished groundwater). They can also absorb water contaminants that would otherwise end up in water bodies. The terminology arose in Maryland, USA in 1990s as a more marketable expression for bioremediation.


Rainwater harvesting

 Collecting rainwater either in storages or the soil mostly close to where it falls; the attempt to increase rainwater productivity by storing it in pondages, wetlands etc., and helping to avoid the need for infrastructure to bring water from elsewhere. Practiced on a large scale upstream this reduces available water downstream.


Rangeland

 A region where grasing or browsing livestock is the main land use.


Raw materials

Materials that are extracted from the ground and processed e.g. bauxite is processed into aluminium


Real-time data

information that is delivered immediately after collection. There is no delay in the timeliness of the information provided. Real-time data is often used for navigation or tracking.

Reclaimed water

  Water taken from a waste (effluent) stream and purified to a level suitable for further use.


Recorded Forest Area

Geographic areas recorded as forests in Government records.


Recovered material

(waste) material that would have otherwise been disposed of as waste or used for energy recovery, but has instead been collected and recovered (reclaimed) as a material input thus avoiding the use of new primary materials.


Recovery rate

(waste) the recovery rate is the percentage of materials consumed that is recovered for recycling.


Recyclables

Strictly, all materials that may be recycled, but this may include the recyclable containers and paper/cardboard component of kerbside waste (excluding garden organics).


Remote sensing
The acquisition and processing of information about a distant object or phenomenon without any physical contact; often done from satellites.

Renewable
An energy source that can be easily replenished i.e. solar, wind, geothermal, hydropower. Renewable energy sources can be used to produce secondary energy sources including electricity and hydrogen.

Reserved Forests

An area so constituted under the provisions of the Indian Forest Act or other State Forest Acts, having full degree of protection. In reserved forests all activities are prohibited unless permitted.

Risk

The probability that something will cause injury or harm.


Sanitation

Sanitation is the process of keeping places clean and healthy, especially by providing a sewage system and a clean water supply. 

Solid waste management

Entire process of storage, collection, transportation, processing, and disposal of solid wastes by any person engaging in such process as a business, or by any government agency, city, municipal authority or any combination thereof. 

Solvent

A liquid capable of dissolving or dispersing another substance (for example, acetone or mineral spirits).


Special populations

People who might be more sensitive or susceptible to exposure to hazardous substances because of factors such as age, occupation, sex, or behaviors (for example, cigarette smoking). Children, pregnant women, and older people are often considered special populations.


Species

Populations of animals that possess common characteristics and freely inter-breed in nature and produce fertile offspring.


Statistics

A branch of mathematics that deals with collecting, reviewing, summarizing, and interpreting data or information. Statistics are used to determine whether differences between study groups are meaningful.


Surface water

Water on the surface of the earth, such as in lakes, rivers, streams, ponds, and springs. 


Teratogen

A substance that causes defects in development between conception and birth. A teratogen is a substance that causes a structural or functional birth defect.


Total Cropped Area

This represents the total area sown once and/or more than once in a particular year, i.e. the area is counted as many times as there are sowings in a year. This total area is known as gross cropped area.


Total Cultivable Area

This consists of net area sown, current fallows, fallow lands other than current fallows, culturable waste and land under miscellaneous tree crops.


Total Cultivated Area

This consists of net area sown and current fallows.


Total Un-Cultivable Area

It is the area arrived at by deducting the total cultivable area from the total reported area.


Total Un-Cultivated Area

It is the area arrived at by deducting the total cultivated area from the total reported area.


Toxic

Poisonous or harmful to the body (ecotoxic relates to damage to the environment). 


Toxic agent

Chemical or physical (for example, radiation, heat, cold, microwaves) agents that, under certain circumstances of exposure, can cause harmful effects to living organisms.


Toxicology

The study of the harmful effects of substances on humans or animals.


Toxin

A poisonous substance that can either be natural (produced by plants, animals or bacteria) or manufactured.


Tropical Cyclone

Storms of various intensities that form over warm tropical and subtropical waters; classified according to intensity and degree of organization and including tropical disturbances, tropical depressions, tropical storms, and hurricanes.



Tropical storm
A warm-core tropical cyclone in which the maximum sustained surface wind (1 minute mean) ranges from 34 to 63 knots (62.4-116 kilometers per hour).

Tsunami
A shallow water progressive wave, potentially catastrophic, caused by an underwater earthquake or volcano that can rise to great heights and catastrophically inundate shore lands.

Tumor

An abnormal mass of tissue that results from excessive cell division that is uncontrolled and progressive. Tumors perform no useful body function. Tumors can be either benign (not cancer) or malignant (cancer). 


Unclassed Forests

An area recorded as forest but not included in reserved or protected forest category. Ownership status of such forests varies from state to state.

United Nations Framework Convention on Climate Change

The UNFCCC and the Convention on Biological Diversity (CBD) were established at the 1992 U.N. Conference on Environment and Development in Rio de Janeiro, Brazil. The Kyoto Protocol was then formulated by the UNFCCC and sets specific timelines and timetables for reducing industrialized nations’ GHG emissions and allows some international trading in carbon credits. For more information visi


Upstream

Those processes necessary before a particular activity is completed e.g. for a manufactured product this would be the extraction, transport of materials etc. needed prior to the process of manufacture cf. downstream.


Urban Heat Islandthe tendency for urban areas to have warmer air temperatures than the surrounding rural landscape, due to the low albedo of streets, sidewalks, parking lots, and buildings. These surfaces absorb solar radiation during the day and release it at night, resulting in higher night temperatures.

Urban metabolism

The functional flow of materials and energy required by cities.


Vaccine

A preparation intended to produce immunity to a disease by stimulating the production of antibodies.


veloway

cycle track; cycleway; contrasts with freeway.


Vermicompost

Vermicomposting is the process of having redworms and other decomposer organisms process our organic waste and turn it into a great natural fertilizer.


Very Dense Forest
Lands with forest cover having a canopy density of 70 percent and above.

Vinyl

type of plastic (usually PVC) used to make products such as fruit juice bottles, credit cards, pipes and hoses.


Virtual water

The volume of water required to produce a commodity or service. First coined by Professor J.A. Allan of the University of London in the early 1990s, though this is now more widely known as cf. embedded (embodied) water.


Volatile organic compound

Molecules containing carbon and differing proportions of other elements such as hydrogen, oxygen, fluorine and chlorine. With sunlight and heat they form ground-level ozone


Vulnerability
The degree of loss to a given element or set of elements within the area affected by a hazard. It is expressed on a scale of 0 (no loss) to 1 (total loss). Also, a set of conditions and processes resulting from physical, social, economic, and environmental factors, which increase the susceptibility of a community to the impact of hazards.

Waste

Any matter, whether liquid, solid, gaseous, or radioactive, which is discharged, emitted, or deposited in the environment in such volume, constituency or manner as to cause an alteration of the environment.


Waste disposal

The activity to get rid of the wastes either by putting the same in a landfill or incinerated or recycled etc.


Waste Reduction

Measures to reduce the amount of waste generated by an individual, household or organisation.


Waste Water
Used water; generally not suitable for drinking.

Water consumption

Water consumption - in water accounting: distributed water use self-extracted water use reuse water use - distributed water supplied to other users - in-stream use (where applicable).

Water cycle

water cycle (hydrological cycle) passage of the water between the oceans and waterbodies, land and atmosphere.

Water Footprint
The total volume of freshwater that is required in a given period to perform a particular task or to produce the goods and services consumed at any level of the action hierarchy. Country water footprint is a concept introduced by Hoekstra in 2002 as a consumption-based indicator of water use in a country – the volume of water needed to produce the goods and services consumed by the inhabitants of a country.

Water intensity

Volume of water used per unit of production or service delivery; this is generally further reduced to monetary unit return per given volume of water used. Essentially equivalent to water productivity.

Water Pollution
Any physical or chemical change in surface water or ground water that can harm living organisms or make water unfit for certain uses. 

Water Resources

Water in various forms, such as groundwater, surface water, snow and ice, at present in the land phase of the hydro-logical cycle—some parts may be renewable seasonally, but others may be effectively mined.


Water restrictions

Mandatory staged restrictions on the use of water, which are relative to water storage levels.

Water treatment

The process of converting raw untreated water to a public water supply safe for human consumption; can involve, variously, screening, initial disinfection, clarification, filtration, pH correction and final disinfection.


Xylem

Tissue in the vascular system of plants that moves water and dissolved nutrients from the roots to the leaves; composed of various cell types including tracheids and vessel elements. Plant tissue type that conducts water and nutrients from the roots to the leaves.

Zebroid
A hybrid animal that results from breeding zebras and horses.

Zero emissions

An engine, motor or other energy source that does not produce any gas or release any harmful gases directly into the environment.


Zero waste

Turning waste into resource; the redesign of resource-use so that waste can ultimately be reduced to zero; ensuring that by-products are used elsewhere and goods are recycled, in emulation of the cycling of wastes in nature.

Zone of saturation

Lower soil layers where all spaces are filled with water.