What are GROUND WATERS - Definition, characteristics, formation and more

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The hydrosphere is an environmental system made up of all the water on the planet, in its different physical states (solid, liquid and gas). Water circulates continuously from one place to another, changing its state, its speed and intensity of flow, giving rise to what we know as the water cycle or the hydrological cycle. Thus, in the hydrosphere it is possible to distinguish several bodies or masses of water: oceans, surface waters (rivers, glaciers, lakes), groundwater and water present in the atmosphere. Approximately 97.5% of the water is concentrated in the oceans and of the remaining 2.5%, a third of the water is underground.

¿What is groundwater exactly? Is groundwater sweet or salty? Can groundwater come to the surface? By reading this Green Ecologist article you will know the answers to these questions. You will also be able to understand the importance of groundwater, what its sources are and its main characteristics, among other details. So, if you're interested, keep reading this overview of what groundwater is.

What is groundwater and its characteristics

The definition of groundwater can be summarized as the set of water that is stored deep or below the surface of the ground, completely saturating the pores of the subsoil. Some of the main groundwater characteristics are:

  • Groundwater is sweet.
  • The physical, chemical and biological composition of water can be modified once it infiltrates the ground due to its interactions with the environment.
  • The major chemical constituents of groundwater are: carbon dioxide (CO2), bicarbonates (HCO3-), carbonates (CO32-), chlorides (Cl-), sulfates (SO42-), nitrate (NO3-), nitrite (NO2-), harmonium (NH4+), calcium (Ca2+), magnesium (Mg2+), sodium (Na+), potassium (K+), silica (SiO2) and dissolved oxygen (O2).

How groundwater is formed

Groundwater is formed from rain water. Once the water precipitates, this infiltrates underground and descends until it is retained in a waterproof layer. This layer of the subsoil allows the storage of water, which fully occupies or saturates the pores or holes in the ground, thus forming the aquifers.

In this other Green Ecologist article we tell you more about How groundwater is formed.

Types of groundwater

Groundwater can be classified according to two criteria: according to its formation or its location. So these are some groundwater examples according to their types.

Depending on the origin or sources of the groundwater, these can be:

  • From infiltration or precipitation.
  • Waters of condensation of night fog in desert areas.
  • Fossils or congenital, which are those bodies of water that were trapped in aquifers thousands of years ago.
  • Youthful waters or magmatic, which are those that emerge for the first time to the surface as a result of volcanic eruptions and geysers (eg: underground water spring).

In function of the groundwater distribution on the ground or, in other words, depending on where the groundwater is, we find:

  • Edaphic waters: It is the groundwater that is located in the aeration zone or unsaturated zone of the subsoil.
  • Suspended waters: They are formed when between the surface and the real saturation zone, there is a thin strip, saturated with water, retained by an impermeable layer.
  • Groundwater: the waters of the phreatic level are those that make up the saturation zone.
  • Confined waters: located between two waterproof layers.
  • Artesian waters: under great pressure, they are stored between impermeable layers, and flow vertically towards the surface.

Groundwater fauna

The biological composition of groundwater can inform us about the quality status of the water resource. The temporal and spatial variability of biocoenosis is subject to the physical-chemical conditions of the environment and the pressure exerted by humans on the underground water bodies.

Between the unknown and valuable fauna that inhabits groundwater or stigofauna, invertebrates abound (among which stand out arthropods) which, together with the bacteria, play a key role in water purification.

In these other articles you can learn about What are arthropods, their characteristics, classification and examples and about Are bacteria living beings? and the Types of bacteria.

Why groundwater matters

Groundwater is a important water reserve for the consumption of drinking water and the performance of industrial and agricultural activities. In addition to being a source of food and enabling economic development, these inland water bodies provide support services, guaranteeing biodiversity, conservation and the proper functioning of ecosystems.

In this other post you will see what is the importance of water.

Overexploitation of groundwater

The overexploitation of aquifers it occurs when water is withdrawn from aquifers at a rate higher than that of natural recharge. How groundwater is used makes it less and less available, endangering aquatic ecosystems or those associated with certain bodies of water. For example, the lack of groundwater inflow to coastal wetlands can accelerate saline intrusion processes and thus alter the balance, morphology and dynamics of these ecosystems.

The exponential growth of the population increases the demand for this resource, contributing to its scarcity in terms of availability, as we remember that water constitutes a closed cycle, without losses or gains; it is simply stored in more or less accessible forms and in one physical state or another. In recent decades, not only have alarms sounded due to a decrease in water reserves of which we have due to the consumptive use of water, but also due to the pollution processes that it undergoes. Mainly agricultural, urban and industrial activities stand out as triggers for the loss of quality of this resource.

Finally, we advise you to read these other articles about What is an aquifer and how it is formed and the Overexploitation of natural resources, its causes and consequences.

If you want to read more articles similar to What is groundwater, we recommend that you enter our category of Other environment.

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