首页
登录
职称英语
Scientists say there has been a severe decrease in the amount of water in La
Scientists say there has been a severe decrease in the amount of water in La
游客
2024-08-18
40
管理
问题
Scientists say there has been a severe decrease in the amount of water in Lake Chad in northern Africa in the last thirty years. They reported that nature and humans share equal blame for this loss.
In 1963, the fresh-water lake covered 25,000 square kilometers. Now the lake is only about five percent of that size. It measures only about 1,300 square kilometers in the dry season.
Four nations surround Lake Chad. People in Niger, Nigeria, Chad, and Cameroon use it for water, fish and plant life.
Michael Coe and Jonathan Foley, water experts at the University of Wisconsin in Madison, reported on Lake Chad in a science journal. They say the area has suffered from a lack of heavy rain for more than thirty years. This has forced people to build systems to carry water to dry land. These irrigation systems further decrease the amount of lake water.
Mr. Coe says Lake Chad will be only a small body of water in the future. He says people still can get water from the lake to drink and for crops. But he says the lake will no longer provide a healthy environment for fish and plant life.
The researchers used a computer to study what caused the water loss. Their computer study estimated the climate and amount of water in the area. The estimate started with written records from the early 1960s. Then the researchers compared the estimates with the area’s recorded climate and water supply for the same period.
The computer study showed results similar to the recorded ones for the first twenty years. But there was a big change in the 1980s. At the time, the lake got smaller much faster than the computer research had estimated.
The researchers say that major irrigation systems were built in the 1980s. The systems took water from two rivers that flow into Lake Chad. The Chari and Logone rivers carry most of the water that enters the lake. Climate changes also were responsible for the reduction. The flow of the two rivers was reduced by almost seventy-five percent.
Scientists say the problem is expected to worsen in the coming years as the population and demand for water continued to increase. [br] When did the scientists find that Lake Chad got smaller much faster?
选项
答案
in the 1980s
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3725289.html
相关试题推荐
ScientistssaytherehasbeenaseveredecreaseintheamountofwaterinLa
ScientistssaytherehasbeenaseveredecreaseintheamountofwaterinLa
ScientistssaytherehasbeenaseveredecreaseintheamountofwaterinLa
Scientistshavedevelopedapioneeringtechnologythatallowschildrenwith
Scientistshavedevelopedapioneeringtechnologythatallowschildrenwith
Scientistshavedevelopedapioneeringtechnologythatallowschildrenwith
______thecalculationisright,scientistscanneverbesurethattheyhaveincl
Scientistsknowthattherearetwobasicapproachestoprolongingforlife.
Scientistsknowthattherearetwobasicapproachestoprolongingforlife.
Scientistsknowthattherearetwobasicapproachestoprolongingforlife.
随机试题
Readthememoandnotesbelow.Completetheformbelow.Writeaword
[originaltext]Mostpeoplehavehadadogorwantedoneastheircompaniona
在重置抽样时,样本均值的标准差为总体标准差σ的()。
与CAD相比,BIM模型的特性不包括()。A.模型信息的完备性 B.模型信息的
电缆竖井中应分层设置防火隔板,电缆沟每隔一定的距离(____)应采取防火隔离措施
女性,35岁,发现血压高3年,血压平时在150~170/80~100mmHg范围
《中国人民银行法》第32条规定,中国人民银行对金融机构以及其他单位和个人的()行
(2019年真题)除另有规定外,应检查黏附力的制剂是A.贴膏剂 B.软膏剂
某水电站投资项目要识别社会分析中的利益相关者,可分为主要利益相关者和次要利益相关
男孩,3岁。生后4个月见表情呆滞,易激惹,不能抬头,伴有惊厥,每日10余次。2岁
最新回复
(
0
)