The Water Cycle
The Water Cycle helps replenish and recycle the water in this world. The water cycle starts in oceans, lakes or even in trees where the water evaporates and rises into the atmosphere. Evaporation is the turning from water to water vapor, transpiration is evaporation from tree roots or leaves. Water then condensates, or changes into clouds, and falls to the ground as precipitation. Precipitation is rain, this rain then either filters underground and becomes ground water or flows back to the water source in runoff. There are a few exceptions to this cycle, sublimation may occur when snow turns directly into water vapor. Also, springs may occur when groundwater appears above ground. All of these make up the Water Cycle, Earth's way of recycling our water.
Earth's Water Basics
Earth's Water is distibuted unevenly about the world, leading to some water shortage or an abundane of water in certain places. Freshwater only makes up 2.5% of our Earth's water and most is trapped in glaciers, ice caps or underground. In fact, nearly 7,000,000 mi3 of freshwater is in glaciers and ice caps. 1.2% of freshwater is surface water and easily accessible to humans. Of this .49% of surface water is in rivers where we get our drinking water, .007% of total water is fresh and in lakes, and .79% of fresh water is underground. Wetlands cover almost 6% of the world, although the water may not be usable. 96% of water is saltwater and in the oceans and not easily used by us. About 3,100 mi3 of water in the form of vapor is i the atmosphere at any given time, often we cannot access this water. More than 2,000,000 mi3 of freshwater is stored within the Earth and out of our reach. In summary, although we may feel that water is a resource that can never be depleted, much is held out of our reach, rendering us victim to water shortages and drought.
Water Quality is important to our health and lifestyle, so we try our best to keep or water clean. However, sometimes our water ends up contaminated. most good quality water comes from the ground, unfortunately, this water is withdrawn faster than it can be replaced. 2.5 billion people in the world live without water sanitation, causing sicknesses to spread. to add to that, two tons of sewage is discharged into the world's water daily. In fact, the amount of wastewater being produced is 6 times more than all the water in the rivers of the world. unfortunately, this means contaminated water for less developed countries. 70% of industrial wastes in developing countries and disposed of in untreated waters. people in Bangladesh are exposed to water containing arsenic daily. Even France has been informed that their drinking water did not meet standards of cleanliness. Hopefully, with the help of the great minds of the world we can improve our water quality before long.