8.9池塘与湖泊
章节大纲
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Why are lakes important?
::为什么湖泊很重要?Lakes are important habitats for lots of plants and animals. The slow motions of the water are easier for organisms to live in than the water from rapidly moving streams . Some animals live on land but get at least part of their food from lakes or ponds . This eagle is fishing for its meal. What would happen if lakes dried up?
::湖泊是许多植物和动物的重要栖息地。 水的缓慢运动比迅速移动的溪流的水更容易让生物生活在其中。 有些动物生活在陆地上,但至少从湖泊或池塘中获取部分食物。 这只鹰正在捕食。 如果湖泊干涸,会发生什么情况?Ponds and Lakes
::池塘和湖泊After a heavy rain , you may find puddles of water standing in low spots. The same principle explains why water collects in ponds and lakes. Water travels downhill, so a depression in the ground fills with standing water. A pond is a small body of standing water. A lake is a large body of standing water. Most lakes have freshwater , but a few are salty. The Great Salt Lake in Utah is an example of a saltwater lake.
::暴雨过后,你可以在低点找到水坑。同样的原则也解释了为什么水会聚集在池塘和湖泊中。水会向下流,因此地底的低潮会充斥着站立水。池塘是一小块站立水。湖是一大块站立水。湖中大部分有淡水,但有一些是咸水。犹他大盐湖就是咸水湖的一个例子。The water in a large lake may be so deep that sunlight cannot penetrate all the way to the bottom. Without sunlight, water plants and algae cannot live on the bottom of the lake. That’s because plants need sunlight for photosynthesis .
::大湖的水可能太深,阳光无法穿透到底部。 没有阳光,水植物和藻类无法生活在湖底。 这是因为植物需要光合作用阳光。Water in Ponds and Lakes
::池塘和湖泊的水Ponds and lakes may get their water from several sources. Some falls directly into them as . Some enters as runoff and some from streams and rivers . Water leaves ponds and lakes through evaporation and also as outflow.
::水池和湖泊可能从几个来源获得水,有些直接流入水池和湖泊,有些进入水池和湖泊,有些进入水池和湖泊,有些进入水池和湖泊,有些进入水池和湖泊,有些进入水池和湖泊,有些进入水池和湖泊,通过蒸发和流出。How Lakes Form
::湖湖形态The depression that allows water to collect to form a lake may come about in a variety of ways. The Great Lakes, for example, are glacial lakes. A glacial lake forms when a scrapes a large hole in the ground. When the glacier melts, the water fills the hole and forms a lake. A kettle lake forms in the sediment left by a glacier when a block of ice melts. Kettle lakes are found where continental glaciers once covered the land ( Figure ). Over time lakes get water from rain, streams, and coming to the surface.
::允许水收集形成湖泊的萧条可能以多种方式出现。例如,五大湖是冰川湖。当地面上一个大洞被刮开时,冰川湖形成冰川湖。冰川融化时,水会填满洞洞,形成湖。冰川留下的沉积物中,冰块融化时,水会形成小湖。发现喀特湖曾经覆盖着陆地(图 ) 。随着时间的推移,湖泊会从雨水、溪流和地表得到水。A moose in a kettle lake at Denali National Park in Alaska.
::在阿拉斯加Denali国家公园的一个水壶湖里 一只驼鹿Other lakes are crater lakes or rift lakes ( Figure ). Crater lakes form when volcanic eruptions create craters that fill with water. Rift lakes form when movements of tectonic plates create low places that fill with water.
::其他湖泊是弹坑湖或裂谷湖(图)。火山爆发时形成火山湖,形成填满水的火山坑。构造板块移动时形成裂谷湖,形成填满水的低位。Craters and rifts become lakes when they fill with water. Where does the water come from?
::当它们填满水时,裂缝和裂缝会变成湖泊。水来自何方?The Great Lakes
::大湖区大湖区Large lakes are similar to oceans. They have and currents. Large lakes can affect patterns. The Great Lakes ( Figure ) contain 22% of the world’s fresh surface water. The largest of them, Lake Superior, has a tide that rises and falls several centimeters each day . The Great Lakes cause “lake effect” snow . In the winter, a large amount of snow may fall downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife.
::大湖与海洋相似,大湖和洋流相似。大湖可以影响形态。大湖(图)占世界淡水地表水的22%。最大的大湖 — — 苏必利尔湖(Lake Superior) — — 每天涨跌几厘米。大湖造成了“湖泊效应 ” 的雪。 在冬季,大湖可能会下下下下大量雪,相对温暖的湖。 大湖有无数鱼类和野生动物。The Great Lakes of North America get their name from their great size.
::北美大湖从他们巨大的面积中取出他们的名字。Reservoirs
::储 储 地Many lakes are not natural, but are human-made. People dam a stream in a suitable spot. Water backs up behind the dam, creating a lake. These lakes are "reservoirs" ( Figure ).
::许多湖泊不是自然的,而是人为的。人们在合适的地方筑起一条溪流。大坝后面有水,形成一个湖。这些湖是“蓄水层”(图 ) 。Hoover Dam, near Las Vegas, Nevada, creates a reservoir on the Colorado River. The reservoir is called Lake Mead.
::内华达州拉斯维加斯附近的胡佛大坝在科罗拉多河上建了一个水库,叫做米德湖。Summary
::摘要- Ponds are small water bodies often fed by springs.
::池塘是小水体,通常由泉水喂养。
- A lake or pond may form wherever water can collect. A lake basin could be a volcanic crater, where a glacier has carved out a depression, or a fault zone.
::湖川盆地可以是火山坑,冰川在火山口中划出了萧条或断层区。
- A reservoir is a man-made lake.
::水库是人造湖
Review
::回顾- Describe how different types of lakes form.
::描述不同类型的湖泊是如何形成的。
- How is a large lake like an ocean? How is it different?
::这么大的湖怎么会像大海?
- What is the difference between ponds and lakes? How are they similar?
::池塘和湖泊之间有什么区别?它们如何相似?
- Ponds are small water bodies often fed by springs.
