Water is one of the most essential elements that keep all livings things alive. Whether humans or animals or birds and insects, everybody needs water to sustain themselves. Water is present practically everywhere as ¾ parts of the earth are covered with water. But how do we get all this water for our needs?
Fact 1 Forms Of Water
Water cycle is the main system that explains the existence and movements of water above, on and in the earth. Water is all moving and changes its states according to the temperature. Water is seen in three forms namely liquid, solid and gaseous states. It is water everywhere either in the form of ice, water or water vapor. But how does all this happen?
Fact 2 What Is Water Cycle?
Water cycle has no starting point. The largest amounts of water exist in the oceans. The sun heats the water in the oceans as well as other smaller water bodies. It evaporates and rises up as water vapor. Some of it is added as ice and snow sublimate directly from the solid state into vapor. The rising air absorbs the water vapor and carries it up into the atmosphere along with water that is transpired from plants and evaporated from the soil. As it rises higher up it becomes cool due to cooler temperatures and this causes the vapor to condense into clouds. The clouds are moved by air currents that grow bigger in size by collecting more water vapor from the atmosphere. These clouds collide with each other and when they become heavy and cannot bear the weight of the water vapor anymore, they fall out of the sky as precipitation.
Fact 3 Various Kinds Of Precipitation
Precipitation does not mean that all the clouds fall to the earth as rain. Some falls as snow and accumulate as ice caps on the peaks of high mountains, glaciers are formed that store frozen water for thousands of years. With the change in weather conditions when the atmosphere becomes warmer and spring arrives the snow packs gradually start melting and it flows over the lands as snowmelt. Most of this snowmelt falls back to the oceans or on land due to gravitation. Some of the waters flow into the rivers in valleys, or streams that again move to join the oceans. Water that seeps under the ground, accumulate and are stored as fresh water lakes. This system of the water going up into the air and again falling back to the earth in different forms in a cyclic order is termed as Water Cycle.
Fact 4 Important Elements Of Water Cycle
The 3 important elements that constitute water cycle are the processes of evaporation, condensation and precipitation.
Evaporation – Evaporation is the process of water turning into vapor by the heat of the sun. It becomes light and travels upwards. Waters of oceans, lakes, rivers and even ponds dry up during the summer months due to this method of evaporation.
Condensation – Condensation is the method in which gas changes into liquid. In water cycle, water vapor condenses and becomes water in the form of clouds. This can take place at ground level as well as in the atmosphere. Water vapor condenses to form clouds. Condensation is also influenced by the sun. Clouds at the ground level are called mist or fog.
Precipitation – Precipitation is the method of any solid or liquid water that falls to the earth in the form of rain, snow and hail. It helps in the water cycle process.
Other methods that are involved in water cycle are transpiration in which water vapor is released by plants and soil and evapotranspiration which is a combination of evaporation and transpiration processes.