The picture illustrates how water circulates in a cyclical manner, which is known as the water cycle.
Overall, the process involves three main stages, namely evaporation, condensation and precipitation, through which the earth gets and maintains the levels of its surface and ground water. Notably, all three forms of water can be seen in this continuous process.
First, as the sun shines in the day time, the surface of oceans gets heated, and the water is converted in to the vapor. As the resulting water vapor is light, it goes up, which is known as the evaporation. Importantly, 80% of the atmospheric water vapor comes from the oceans in this way. After being evaporated, condensation takes place, in which vapor particles combine together to form clouds higher in the sky. When clouds are overloaded and becomes heavier, it accounts for precipitation, whereby water returns to the earth in the form of either rain or snow, from which lakes are filled with and mountain tips are usually covered with, respectively. Once precipitated, certain percentage of water flows on the earth’s surface, known as surface run off, ultimately goes in to rivers and finally to oceans, from which salt water intrudes at merging points. In addition to the surface water, a certain proportion of water is absorbed by the ground and known as the ground water, which can be found above the impervious layer of the earth.
- The bar chart below shows the production of the world s oil in OPEC and non OPEC countries Write a short report for a university lecturer describing the information shown below 67
- In some countries an increasing number of people are suffering from health problems as a result of eating too much fast food It is therefore necessary for governments to impose a higher tax on this kind of food To what extend do you agree or disagree with 67
- Some people claim that not enough of the waste from homes is recycled They say that the only way to increase recycling is for government to make it a legal requirement To what extent do you think laws are needed to make people recycle more of their waste 73
- Some people think that music plays an important role in society Others think it is simply a form of entertainment Discuss both sides and give your opinion 89
- The diagram below shows the water cycle which is the continuous movement of water on above and below the surface of the Earth 10