The water is a composite substance molecules having two hydrogen atoms and an oxygen atom. Most of the surface of our planet is covered by water, an essential element for life. Underground, on the other hand, is what is located under the ground.
On planet Earth, much of the water is found in aquifers that are located below the planetary surface. Aquifers are geological formations that store groundwater, a very valuable resource since it allows the supply of a high percentage of the world’s population.
These aquifers receive water from rainfall. When rainfall reaches the ground, it seeps out and reaches underground rocks. Beneath the surface, groundwater is in motion by gravity and may even end up in the oceans. There is groundwater that is also lodged in pores and in sediments that absorb it.
In aquifers a saturation zone can be distinguished and, above it, an aeration zone. The saturation zone is above the impermeable layer and houses groundwater in its pores. At the top of the saturation zone is the water table, the amount of water depending on the season. Above the water table, and before the surface, the aeration zone is located.
The over – exploitation and pollution endanger aquifers and, therefore, threaten groundwater. When water is continuously drawn, the water table can drop below the natural depth and eventually dry up. Human activity, on the other hand, can deposit pollutants in groundwater, which is generally drinkable.
It is important to know that aquifers can be of various types:
-If you take into account what is the pressure to which the water is subjected, we come across confined, semi-confined and unconfined.
-On the other hand, if the criterion taken into account is the set of materials that shape the aquifers, there are the cracks, which are supported by what are consolidated rocks, and the porous ones. The latter are those that are made up of materials such as sand or gravel, for example.
Other important data that exist and that are worth considering about groundwater are the following:
-It also responds to the name of groundwater runoff.
-It is closely related to the so-called surface water, although they are different and should not be confused. Thus, when it rains, hails or snows a part of these precipitations come to flow along the surface of the earth, through streams or rivers, for example, and that is what responds to the name of surface water. For its part, the underground is the other part of the fallen rainfall that infiltrates the terrain.
-The spaces in which the underground water comes to the surface are the so-called springs. These can be of different types, such as landfill; those of reef or crack and emergency calls.
-To proceed to capture groundwater, what is done are wells and soundings.
