Desertification: A Serious and Growing Problem

The U.S. Situation

Overall, the United States has plenty of fresh water, but much of its annual runoff is not in the desired place, occurs at the wrong time, or is contaminated from agricultural and industrial activ­ities. Most of the eastern half of the country usually has ample average annual precipitation, while much of the western half has too little. Many major urban centers in the United States are located in areas that already have inadequate water or are projected to have water shortages by 2000.

In the eastern half of the United States, where there is usually no shortage of water, the major prob­lems are flooding, inability to supply enough water to some large urban areas, and increasing pollution of rivers, lakes, and groundwater. For example, 3 million residents of Long Island, New York, must draw all their water from an underground aquifer that is becoming severely contaminated by industrial wastes, leaking septic tanks and landfills, and salt water from the ocean, which is drawn into the aquifer when fresh water is withdrawn.

The major water problem in arid and semiarid areas in the western half of the country is a shortage of runoff due to low average precipitation, high rates of evaporation, prolonged periodic drought, and rapidly declining water tables as farmers and cities deplete groundwater aquifers faster than they are recharged. Present water shortages and conflicts over water sup­plies will get much worse if more industries and peo­ple migrate west as projected and compete with farm­ers for scarce water.

Упражнение 8.

Выберите из текста в упражнении 7 10–15 основных, с точки зрения смысловой нагрузки, слов (ключевые слова). Определите,
к каким частям речи они относятся.

Упражнение 9.

Составьте 5 альтернативных вопросов к тексту из упражнения 7.

Упражнение 10.

(Парная работа) Ответьте на вопросы, составленные в упражнении 8

Упражнение 11.

Переведите текст письменно. (Контрольное время – 30 минут)

The conversion of rangeland (uncul­tivated land used for animal graz­ing), rain-fed cropland, or irrigated cropland to desertlike land with a drop in agricultural productivity of 10% or more is called desertifica­tion. Moderate desertification causes a 10% to 25% drop in productivity; severe desertification causes a 25% to 50% drop; and very severe deser­tification causes a drop of 50% or more and usually the formation of massive gullies and sand dunes.

Prolonged drought and hot temperatures may accelerate the desertification process. But its basic causes are overgrazing of rangeland by concentrating too many livestock on too little land area; improper soil and water resource management that leads to increased erosion, sal-inization, waterlogging, cultivation of marginal land with unsuitable terrain or soils, and deforestation and strip mining without adequate replanting.

Each year, the amount of deser­tified land grows by at least 20 mil­lion hectares (49 million acres)—an area equal to that of South Dakota. According to the UN Environmental Programme, one-fifth of the world's people now live in areas that may become desertified over the next 20 years.

The spread of desertification can be halted or sharply reduced by improved management of range-land, forest, soil, and water resources, and much currently desertified land can be reclaimed. The total cost of such prevention and rehabilitation would be about $141 billion. Although this amount may seem staggering, it is only five and one-half times the estimated $26 billion annual loss in agricultural productivity from desertified land. Thus once this potential productiv­ity is restored, the costs of the pro­gram could be recouped in five to ten years. However, funds now devoted to preventing desertifica­tion and restoring desertified lands fall far short of the need.

Упражнение 12.

В правой колонке найдите русские эквиваленты следующих английских словосочетаний из текста Desertification: A Serious and Growing Problem:

1. rangeland 2. animal grazing 3. irrigated cropland 4. massive gullies 5. prolonged drought 6. desertification process 7. waterlogging 8. marginal land 9. too many 10. too little

a. слишком много b. орошаемая земля c. длительная засуха d. заболачивание e. слишком мало f. малоплодородная земля g. массивные овраги h. пастбище i. процесс опустынивания j. выпас животных

Дата добавления: 2014-12-27