H-H

Equivalent inhabitant. Theoretical population unit used in technical calculations of wastewater production. Abbreviation hab-eq.
Habitat. Place and type of environment in which organisms live.
Halophytes. Plants that live in saline soils. In many cases these are species that tolerate salinity and occupy saline habitat to the exclusion of other species., but in other cases these are species that need high concentrations of salt.
Hectare. Unit of area equivalent to 100 areas and, therefore, a 10,000 square Metres. Abbreviationhe has. 
cubic hectometer. Unit of volume equivalent to 1.000.000 of cubic meters. Abbreviation Hm3.
Heliophiles. Plants that grow well in bright lighting conditions. The heliophilous scrub usually colonizes as a pioneer the lands that have lost the vegetation cover due to fire, thus initiating the first stages of ecological succession.
Herbicides. Pesticides used in agriculture to eliminate undesirable plants. Like other pesticides, Its use can cause environmental problems due to toxicity or accumulation through food webs.
Hexaclorociclohexano. Organochlorine compound obtained by chlorination of benzene. It has insecticidal properties and is toxic to people.. Formula C6H6Cl6.
Polycyclic aromatic hydrocarbons. Aromatic hydrocarbons with two or more benzene rings (cycles with conjugated double bonds). Among them are carcinogens such as benzopyrene and dibenzocridine.
Aromatic hydrocarbons. Cyclic hydrocarbons with conjugated double bonds, like benzene, C6H6.
Hydrocarbons. Organic compounds formed by carbon and hydrogen. They can be formed by open hydrocarbon chains (aliphatic hydrocarbons, for example propane), or closed forming cycles or rings (cyclic hydrocarbons, for example cyclohexane). Hydrocarbons whose rings contain conjugated double bonds are aromatic hydrocarbons., for example, benzene. There are numerous derivatives of hydrocarbons, for example chlorinated and fluorinated. Both among hydrocarbons and among their derivatives there are numerous substances of industrial importance., agricultural, medical and environmental (fuels, pesticides, toxic, etc.). 
Hydrogen. It is the simplest and most abundant chemical element in the Universe. atomic number 1 and atomic mass 1.008. It is a flammable gas. It can be obtained by electrolysis of water or by the action of a strong acid on a metal.. It is used for welding and hydrogenating fats.. H symbol.
Hydrosphere. Earth's water layer, distributed between several liquid compartments and one solid, which are marine waters of seas and oceans, continental waters of rivers, lakes and underground and solid water from the polar caps and high mountains. These compartments, especially those made of liquid water, They are connected through the atmosphere and the water it contains, by the water cycle.
Hierro. chemical element of group VIII of the periodic table. It is a transition metal with atomic number 26 and atomic mass 55.847. Given its electronic structure, it has magnetic properties. It is a micronutrient in vegetables and an essential component in the hemoglobin molecule. It is an essential constituent of steel and has numerous technical and industrial applications.. Faith symbol.
hypocenter. Focus of an earthquake. Place where the release of energy that gives rise to the earthquake occurs. Ideally the focus is usually considered as a point located at a certain depth, but it may actually be located on a fault, Therefore, it is a non-punctual or extensive focus.. Earthquake hypocenters can be shallow or deep. The maximum depth recorded is about 700 km.
Histosol. This is the name given to soils with a high content of organic matter., very thick, typical of swampy areas.
Fungus. Fungi Kingdom Organism. Previously considered vegetables, currently (five kingdoms system) They are treated as a separate kingdom, the one with the mushrooms. They are non-photosynthetic eukaryotic organisms., heterotrophs (saprophytes or parasites), unicellular or multicellular. The latter are made up of a mycelium, which is a set of hyphae or cellular filaments, whether septated or not.
Hora. time unit. Each of the 24 parts into which the duration of the average solar day is divided. Abbreviationh. 
Relative humidity. Relationship, expressed as a percentage, between the amount of water vapor existing in the air and the amount that would saturate this air at a given temperature and pressure.
Wetland: This term encompasses a wide variety of environments, that share a property that differentiates them from terrestrial ecosystems: the presence of water as a characteristic element, which plays a fundamental role in determining its structure and ecological functions. The Convention on Wetlands (Ramsar, Irán, 1971) defines these environments as: “the expanses of marshes, swamps and peat bogs or surfaces covered with water, whether they are natural or artificial, permanent or temporary, stagnant or current, sweets, sweet o sweet, including areas of marine water whose depth at low tide does not exceed six meters.
There. Aerosol visible. Suspended particles, smaller than one micron in diameter, from the condensation of vapors, of chemical reactions or combustion processes.
Humus: It is made up of all the organic substances that are both in the soil and above it, and that have been formed by the decomposition of dead plants. It has a large amount of components that are essential for the development of plants and that they absorb through the roots..