More than 70% of the planet is covered by water.
From the Latin aqua , water is a substance whose molecules are composed of one oxygen atom and two hydrogen atoms . It is an odorless (odorless), tasteless (flavorless) and colorless (colorless) liquid, although it can also be found in a solid state (when it is known as ice ) or in a gaseous state ( vapor ).
Water is the component that appears most abundantly on the Earth's surface (it covers about 71% of the Earth 's crust). It forms the oceans, rivers and rain, in addition to being a constituent part of all living organisms. The circulation of water in ecosystems occurs through a cycle that consists of evaporation or transpiration, precipitation and movement towards the sea.
Types of water: fresh, drinking, salty and mineral
Water that contains a minimum amount of dissolved salts (unlike seawater, which is salty ) is known as fresh water . Through a purification process, humans manage to convert fresh water into drinking water , that is, suitable for consumption thanks to the balanced value of its minerals. It is important to highlight that the scarcity of drinking water in many regions of the planet causes more than 5 million deaths per year.
Mineral water , as its name indicates, contains minerals and other dissolved substances, in such a way that therapeutic value is added or the flavor is altered. This type of water is what is sold packaged throughout the world for human consumption.
The problem of scarcity
Water scarcity is a problem that occurs everywhere on the planet . Around 20% of the world's population lives in areas where there is not enough water, and another 10% is close to this situation. On the other hand, 25% must face the lack of resources on the part of their country to transport water from aquifers and rivers.
Lack of access to drinking water is a global problem.
For many, water scarcity has become one of the most urgent issues to resolve in the 21st century, partly due to the excessive consumption that took place during the previous hundred years, whose rate doubled the birth rate. Although it is not correct to say that the entire Earth suffers from a lack of water, the number of areas that lack this vital resource is growing worryingly.
Human responsibility in the lack of water
As is known, the action of our species is, in large part, responsible for this phenomenon: the amount of drinking water present in the entire world is enough to supply us all; However, given the irregularity with which it is distributed and the enormous waste by a large percentage of the population, its management becomes unsustainable.
Hydrology generally uses the relationship between water and population to measure scarcity, which exists when the annual water supply to a region decreases by 1,000 cubic meters per person; We speak of water stress , however, when the decrease is 1700 cubic meters. Absolute scarcity occurs when each individual has access to less than 500 cubic meters per year.
In other words, water scarcity occurs when the demand for said resource cannot be satisfied, either due to its quantity or quality. It is important to remember that it is not only used for drinking, but that humans have given it other uses, which also enter into the equation.
For this reason, scarcity is a relative concept, a phenomenon that can arise from excessive demand in an environment that could well supply real needs, or from the lack of the minimum necessary for the life of its users.