by Miguel Romão, 11º Zi Escola Secundária de Loulé
Water is found in several physical states. In the atmosphere it is in a gaseous state, resulting from the evaporation of wet all surfaces - seas, rivers and lakes; liquid form is the most common form of water, found on large deposits on the planet’s surface, like the oceans and seas (salt water), in rivers and lakes (freshwater) and also underground, forming the so-called aquifers. Finally, we can also find the water in solid form in the coldest regions of the planet, the poles and at high altitudes (not to mention our home freezers). The gaseous state, in the atmosphere, water can rush in liquid form, such as rain, dew or fog, or in solid state, such as snow or hail.
The importance of water isn’t only because of its extension on Earth’s surface but also because of its primordial importance on several processes that are conditioning of life and human activity.
Nonetheless its abundance, only 2.5% of the water of the planet is drinkable fresh water, which is the only water that is of potential human use.
The main source of fresh water is the rain that falls over land. About 65% of this water goes back to the atmosphere through the water cycle. The rest will be part of superficial water and part as aquifers.
Water is found in several physical states. In the atmosphere it is in a gaseous state, resulting from the evaporation of wet all surfaces - seas, rivers and lakes; liquid form is the most common form of water, found on large deposits on the planet’s surface, like the oceans and seas (salt water), in rivers and lakes (freshwater) and also underground, forming the so-called aquifers. Finally, we can also find the water in solid form in the coldest regions of the planet, the poles and at high altitudes (not to mention our home freezers). The gaseous state, in the atmosphere, water can rush in liquid form, such as rain, dew or fog, or in solid state, such as snow or hail.
The importance of water isn’t only because of its extension on Earth’s surface but also because of its primordial importance on several processes that are conditioning of life and human activity.
Nonetheless its abundance, only 2.5% of the water of the planet is drinkable fresh water, which is the only water that is of potential human use.
The main source of fresh water is the rain that falls over land. About 65% of this water goes back to the atmosphere through the water cycle. The rest will be part of superficial water and part as aquifers.
