Many world's large lakes are drying up

山東 李全忠

主題語境：自然生態 篇幅：312詞 建議用時：7分鐘

1More than 50 percent of large lakes in the world are losing water,according to a groundbreaking new assessment published inScience.The main causes are warming climate and unsustainable human consumption.

2Lead author Fangfang Yao,a climate fellow at the University of Virginia,said this is the first comprehensive assessment of trends and drivers of global lake water storage variability based on an array (一系列) of satellites and models.

3The team used 250,000 lake-area pictures captured by satellites between 1992 and 2020 to survey the area of 1,972 of Earth's large lakes.They collected water levels from nine satellite altimeters and used long-term water levels to reduce any uncertainty.For lakes without a long-term level record,they used recent water measurements made by newer instruments on satellites.Combining current level measurements with longer-term area measurements allowed scientists to understand the changes in lake levels over decades.

4The results were striking: 53 percent of lakes globally experienced a decline in water storage.Yao and his colleagues also assessed storage trends in reservoirs (水庫).They found that nearly two-thirds of Earth's large reservoirs experienced significant water losses.“Sedimentation (沉 積 作用) dominated the global storage decline in existing reservoirs,”said Ben Livneh,also a co-author,CIRES fellow,and associate professor of engineering at CU Boulder.In long-established reservoirs—those that were filled before 1992—sedimentation was more important than droughts and heavy rainfall years.

5Globally,freshwater lakes and reservoirs store 87 percent of the planet's fresh water,making them a valuable resource for both humans and ecosystems.Unlike rivers,lakes are not well monitored,yet they provide water for a large part of humanity—even more than rivers.It is estimated that roughly one-quarter of the world's population,2 billion people,lives in the basin of a drying lake,which indicates an urgent need to incorporate human consumption,climate change,and sedimentation impacts into sustainable water resources management.

Reading

Check

Detail 1.What problem does the new study focus on?

A.Severe water shortage of global big lakes.

B.An increase in the waste of water resources.

C.Human activities' damaging effects on lakes.

D.The importance of lakes to Earth ecosystems.

Gist 2.What is paragraph 3 mainly about?

A.The introduction to Earth's big lakes.

B.The difficulties of measuring water levels.

C.The process of scientists conducting the research.

D.The advantages of applying satellites to collecting data.

Detail 3.What is the main cause of the storage decline in reservoirs?

A.Sedimentation. B.Frequent rainfall.

C.Long-term droughts. D.Excessive use of water.

Inference 4.What does the author suggest in the last paragraph?

A.Limiting the development of lake resources.

B.Taking urgent action to control human consumption.

C.Solving the water problem of people around drying lakes.

D.Improving the management of sustainable water resources.

Language

Study

Ⅰ.Difficult sentence in the text

It is estimated that roughly one-quarter of the world's population,2 billion people,lives in the basin of a drying lake,which indicates an urgent need to incorporate human consumption,climate change,and sedimentation impacts into sustainable water resources management.據估計，大約四分之一的世界人口，即約20 億人生活在干燥的湖泊流域，這表明迫切需要將人類消耗、氣候變化和沉積的影響納入可持續的水資源管理。

【點石成金】句中的that引導的是一個主語從句，it作形式主語；which引導的是定語從句，且在從句中作主語。

Ⅱ.Fill in the blanks with the words and phrase in the box in proper forms.

more than assessment variability combining measurement

1.Decisions could be made on the basis of price,delivery dates,after-sales service or any other ________.

2.In 1986,________ three million were receiving unemployment benefit in America.

3.Up until that point,Leah had followed traditional ________ of success.

4.The ________ of hot weather and decreased water supplies is hurting many industries.

5.Officials arrived to ________ whether it was safe to bring emergency food supplies into the city.