GroundwaterGroundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table.
InsecticideInsecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.
PyrethroidA pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (Chrysanthemum cinerariaefolium and C. coccineum). Pyrethroids are used as commercial and household insecticides. In household concentrations pyrethroids are generally harmless to humans. However, pyrethroids are toxic to insects such as bees, dragonflies, mayflies, gadflies, and some other invertebrates, including those that constitute the base of aquatic and terrestrial food webs.
Groundwater pollutionGroundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. This type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution.
CyhalothrinCyhalothrin is the ISO common name for an organic compound that, in specific isomeric forms, is used as a pesticide. It is a pyrethroid, a class of synthetic insecticides that mimic the structure and properties of the naturally occurring insecticide pyrethrin which is present in the flowers of Chrysanthemum cinerariifolium. Pyrethroids such as cyhalothrin are often preferred as an active ingredient in agricultural insecticides because they are more cost-effective and longer acting than natural pyrethrins.
PesticidePesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampricide. The most common of these are herbicides, which account for approximately 50% of all pesticide use globally. Most pesticides are intended to serve as plant protection products (also known as crop protection products), which in general, protect plants from weeds, fungi, or insects.
Pesticide resistancePesticide resistance describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest. Pest species evolve pesticide resistance via natural selection: the most resistant specimens survive and pass on their acquired heritable changes traits to their offspring. If a pest has resistance then that will reduce the pesticide's efficacy efficacy and resistance are inversely related. Cases of resistance have been reported in all classes of pests (i.e.
Pesticide applicationPesticide application refers to the practical way in which pesticides (including herbicides, fungicides, insecticides, or nematode control agents) are delivered to their biological targets (e.g. pest organism, crop or other plant). Public concern about the use of pesticides has highlighted the need to make this process as efficient as possible, in order to minimise their release into the environment and human exposure (including operators, bystanders and consumers of produce).
Groundwater remediationGroundwater remediation is the process that is used to treat polluted groundwater by removing the pollutants or converting them into harmless products. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. Globally, between 25 per cent and 40 per cent of the world's drinking water is drawn from boreholes and dug wells. Groundwater is also used by farmers to irrigate crops and by industries to produce everyday goods.
Arsenic contamination of groundwaterArsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater. It is a high-profile problem due to the use of deep tube wells for water supply in the Ganges Delta, causing serious arsenic poisoning to large numbers of people. A 2007 study found that over 137 million people in more than 70 countries are probably affected by arsenic poisoning of drinking water.
Groundwater rechargeGroundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally (through the water cycle) and through anthropogenic processes (i.
Groundwater modelGroundwater models are computer models of groundwater flow systems, and are used by hydrologists and hydrogeologists. Groundwater models are used to simulate and predict aquifer conditions. An unambiguous definition of "groundwater model" is difficult to give, but there are many common characteristics. A groundwater model may be a scale model or an electric model of a groundwater situation or aquifer. Groundwater models are used to represent the natural groundwater flow in the environment.
Mosquito netA mosquito net is a type of meshed curtain that is circumferentially draped over a bed or a sleeping area, to offer the sleeper barrier protection against bites and stings from mosquitos, flies, and other pest insects, and thus against the diseases they may carry. Examples of such preventable insect-borne diseases include malaria, dengue fever, yellow fever, zika virus, Chagas disease and various forms of encephalitis, including the West Nile virus.
Drinking waterDrinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, age, health-related issues, and environmental conditions. Recent work showed that the most important driver of water turnover which is closely linked to water requirements is energy expenditure. For those who work in a hot climate, up to a day may be required.
Soil contaminationSoil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons (such as naphthalene and benzo(a)pyrene), solvents, pesticides, lead, and other heavy metals.
BiopesticideA biopesticide is a biological substance or organism that damages, kills, or repels organisms seen as pests. Biological pest management intervention involves predatory, parasitic, or chemical relationships. They are obtained from organisms including plants, bacteria and other microbes, fungi, nematodes, etc. They are components of integrated pest management (IPM) programmes, and have received much practical attention as substitutes to synthetic chemical plant protection products (PPPs). The U.S.
Water qualityWater quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through treatment of the water, can be assessed. The most common standards used to monitor and assess water quality convey the health of ecosystems, safety of human contact, extent of water pollution and condition of drinking water.
OrganophosphateIn organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered as esters of phosphoric acid. Like most functional groups, organophosphates occur in a diverse range of forms, with important examples including key biomolecules such as DNA, RNA and ATP, as well as many insecticides, herbicides, nerve agents and flame retardants.
Leaching (agriculture)In agriculture, leaching is the loss of water-soluble plant nutrients from the soil, due to rain and irrigation. Soil structure, crop planting, type and application rates of fertilizers, and other factors are taken into account to avoid excessive nutrient loss. Leaching may also refer to the practice of applying a small amount of excess irrigation where the water has a high salt content to avoid salts from building up in the soil (salinity control). Where this is practiced, drainage must also usually be employed, to carry away the excess water.
ConiferConifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (pɪˈnɒfᵻtə,ˈpaɪnoʊfaɪtə), also known as Coniferophyta (ˌkɒnᵻfəˈrɒfᵻtə,-oʊfaɪtə) or Coniferae. The division contains a single extant class, Pinopsida. All extant conifers are perennial woody plants with secondary growth. The great majority are trees, though a few are shrubs. Examples include cedars, Douglas-firs, cypresses, firs, junipers, kauri, larches, pines, hemlocks, redwoods, spruces, and yews.
