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
12
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:https://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
Onceaplanisstarted,heis(determine)______tofollowitthrough.determined分析
买进股票组合的同时卖出相同数量的股指期货合约是()。A、买入套期保值B、跨期套利C、反向套利D、正向套利D担心未来价格上涨,买入股指期货合约为买
音像制品责任编辑的工作内容不包括( )。A.担任导演并与主创人员、主要演员和其
在高等学校科研应遵循的原则中,教学的开展与科研的进行应互为条件、相互促进的原则属
诊断巨幼细胞贫血的重要指标是A.叶酸和维生素B测定 B.骨髓象 C.胃液分析
决策制定角色有四种,它们是()。A.企业家角色 B.谈判者角色 C.混乱驾
某地按照“众人的事情由众人商量”原则,以顺口溜、打油诗、俏皮话等易懂易记的方式制
已知网络计划中,工作M有两项紧后工作,这两项紧后工作的最早开始开始时间分别为第1
133.企业、农村、机关、学校、科研院所、街道社区、社会团体、社会 中介组织、
逆向服务是在产品(服务)销售以后,企业向顾客提供实现产品(服务)使用价值的服务。
最新回复
(
0
)