Agro-environmental indicator
Parameter measured to monitor changes either in the state of environmental resources used or affected by agriculture that affect the state of these resources is called agro-environmental indicator. For example, soil quality, water quality, agro-ecosystem biodiversity, climatic change, farm resource management and production efficiency. These indicators are important because they reflect the sustainability of the agricultural practices being followed.
Agro-biodiversity
The harmonious existence of many plant and animal species on the farm is referred to as agro-biodiversity. It includes the cultivated and non-cultivated species. Agro-biodiversity is a fundamental feature of farming systems around the world. It includes many types of biological resources which are associated with agriculture, like genetic resources, edible plants and crops, cattle, freshwater fish, soil organisms vital to soil fertility, naturally occurring insects, bacteria, fungi that control insect pests and diseases of domesticated plants and domesticated animals, etc. It refers to the biodiversity that is associated with farming systems.
Air Quality Modelling
It is used for determining and visualizing the significance and impact of emissions to the atmosphere. They are especially useful to policy-makers whose decisions are often based on emission measurements.
Air Quality Index
It is a numerical scale that indicates the level of pollution in air.
Acid rain (acid precipitation)
It is rain mixed mainly with nitric and sulphuric acid that arise from emissions released during the burning of fossil fuels such as coal containing high contents of sulphur or industrial process. Acid rain usually has pH less than 5.6. Even the cleanest rains are slightly acidic due to the presence of carbon dioxide in dissolved form. Acid deposition occurs not only as rain, snow or mist but also as dry particles, which are readily absorbed by lakes and rivers. Acid rain damages the chemical balance of the soil by removing minerals from it. These minerals then pass on to water bodies and disturb the aquatic life. Acidic gasses can travel up to distances of 500 km a day depending on wind speed causing harm in another country.
Agronomy
Refers to the science of soil management, land cultivation and crop production. It is a part of agricultural science that mainly deals with the principles of crop production, soil and water conservation techniques, etc.
Advanced oxidation process
One of several combination oxidation processes. Advanced chemical oxidation processes use (chemical) oxidants to reduce COD/BOD levels and to remove both organic and oxidizable inorganic components. The processes can completely oxidise organic materials to carbon dioxide and water although it is often not necessary to operate the processes to this level of treatment.
Activated carbon
Highly adsorbent form of carbon which is used to remove odors and toxic substances from liquid or gaseous emissions. In waste treatment it is used to remove dissolved organic matter or colour from waste water. It is also used in motor vehicle evaporative control systems and as an antidote to certain poisonous substances.
Alternative energy
Include sources of energy which are non conventional and provide for decentralized generation of power. These sources provide energy without the use of fossil fuels. Examples include power generation from geothermal, solar, wind and tidal among others. These sources are seen as alternative to conventional sources of energy based on fossil fuels.
Autochthonous
Rock which has not been moved from its original site of formation
Archipelago
A chain or cluster of islands
Allochthonous
A large block of rock which has been moved from its original site of formation, usually by low angle thrust faulting.
Aquifer
A body of saturated rock or sediment through which water can move readily.
Alluvium
Soil or sediments deposited by a river or other running water.
Aquaculture
The cultivation of fish, shellfish, and/or other aquatic animals or plants, including the processing of these products for human use.