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Skim the text 1. Write down an annotation of the text. Title the text.


Text 1

Water controlled is a friend, water in flood is an enemy. Floods occur often and are very destructive, largely because man upsets nature’s balance. Thus when the natural forest areas are eliminated in order to get timber, the water formerly absorbed and stored in the porous forest soil runs off uncontrolled, downhill. Excessive cutting of timber, clearing of land, and bad farming practices have all led to destructive floods.

Forest lands usually control the water movement of a locality. They keep moisture, store water, and provide a steady regular and dependable flow of water.

Lack of forest land produces an independent flow of water, rising to rapid flood peaks after the rains, followed by quick drying up of rivers in the dry seasons.

Failure to store water in the soil or in natural reservoirs causes failure of the water supply during the dry months of the year. Water shortage can cause serious crop failures. There are countries where farmers today harvest only one profitable crop in five or six years, because of drought. Ruined farms, dust storms, and semidesert conditions now prevail in these regions where only one generation ago there was a sea of waving grass and profitable crops. Water power is needed in many regions to turn dynamos and generate electric power. Failure of a water supply can stop hydroelectric output.

Watersheds must be kept clean. A watershed is usually a forest or grassland area that stores water. It is very important to farms, industries and population that watersheds be maintained in good condition. The trees, branches, leaves, shrubs, grass, plants break the force of falling rain. They keep the rain from eroding the soil. They improve the porous nature of the soil and help it absorb water. The water does not run off this kind of surface rapidly; instead it sinks into the ground. When a watershed is in good condition it provides a steady, fresh flow of water. Most watersheds are valuable, not only for supplying water, but also for many other pur­poses. Some of these are livestock grazing, recreational parks, and sources of timber.

 

Topic for discussion.

Forests of your native place.

 

Unit 3 Rainforests

Text1

Tropical rainforests







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