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  • 保护海岸线

    Lesson
    ::经验教训

     

    lesson content

     

    Why do you see man-made structures on some beaches?
    ::你为什么在海滩上看到人造建筑?

    When you go to a  beach , you may see man-made structures like these. Most attempt to keep the sand where people want the sand to be. A smaller number keep the sand from coming into an area where it is not wanted.
    ::当你去海滩时,你可能会看到这样的人为结构。 多数人试图把沙子留在人们希望沙子存在的地方。 少量人阻止沙子进入一个人们不希望沙土存在的地区。

    Protecting Shorelines
    ::保护海岸线

    Shores are attractive places to live and vacation. But development at the shore is at risk of damage from waves. Wave  erosion  threatens many homes and beaches on the ocean. This is especially true during  storms , when waves may be much larger than normal. People build several types of structures to protect beaches.
    ::海岸是居住和度假的有吸引力的地方。 但海岸的发展面临海浪破坏的风险。 海浪侵蚀威胁着海洋上的许多家庭和海滩。 在风暴期间尤其如此,因为海浪可能比正常大得多。 人们建造了几种保护海滩的结构。

    Breakwaters
    ::隔水

    Barrier islands  provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called  breakwaters . Breakwaters also protect the shoreline from incoming waves. The breakwater pictured below ( Figure   ) runs parallel to the coast like a barrier island.
    ::屏障岛屿为海岸线提供自然保护。 风暴波在到达海岸之前袭击了屏障岛屿。 人们还建造了人为屏障,称为防波堤。 断流水也保护海岸线免受波浪的侵袭。 下面(图 ) 的断流水像屏障岛一样与海岸平行。

    A breakwater protecting a beach

     

    This rocky breakwater protects the beach at Tenerife in the Canary Islands, Spain.
    ::这块岩石防波堤保护西班牙加那利群岛 特纳里费海滩

    Groins
    ::农村

    Longshore drift  can erode the  sediment  from a beach. To keep this from happening, people may build a series of groins. A  groin  ( Figure   ) is wall of   or concrete. The structure juts out into the ocean perpendicular to the shore. A groin stops the longshore movement of sand. Sand collects on the up-current side of the groin. Sand on opposite of side of the groin erodes. This reduces beach erosion.
    ::长岸漂流会侵蚀海滩上的沉积物。 为了防止这种情况发生, 人们可能会建立一系列的腹股沟。 腹股沟( Figure ) 是墙壁或混凝土 。 结构突入与海岸垂直的海洋中。 腹股沟阻止了沙的长岸移动。 沙丘聚集在腹股沟的上侧。 腹沟对面的沙子腐蚀了。 这减少了海滩侵蚀 。

    A groin slows sand on the up-current side

     

    This groin slows sand on the up-current side. Can you determine which way the water is moving based on where the sand is collecting?
    ::这股股沟让上流的沙子减慢。你能确定水的移动方式吗?

    Seawalls
    ::海堤

    A  seawall  is also parallel to the shore. However, a seawall is built onshore.  Seawalls  ( Figure   ) protect the shore from incoming waves.
    ::海上墙也与海岸平行,但海上墙在岸上建造,海墙(图)保护海岸免受波浪的侵袭。

    A seawall protecting a shore

     

    This seawall protects a shore in Vancouver.
    ::这个海堤保护温哥华的海岸

    Does Protection Work?
    ::保护是否有效?

    People do not always want to choose safe building practices, and instead choose to build a beach house right on the beach. Protecting development from wave erosion is difficult and expensive.
    ::人们并不总想选择安全的建筑方法,而是选择在海滩上建造海滩房屋。 保护发展免受波浪侵蚀既困难又昂贵。

    Protection does not always work. The northeastern coast of Japan was protected by anti-  seawalls. Yet waves from the 2011 tsunami that resulted from the Tōhoku   washed over the top of some seawalls and caused others to collapse. Japan is now planning to build even higher seawalls to prepare for any future (and inevitable) tsunami.
    ::保护并不总是有效的。 日本东北海岸受到反海墙的保护。 但2011年海啸的波浪却冲过一些海墙的顶端,并导致其他海墙倒塌。 日本目前正在计划建造更高的海堤,为任何未来(和不可避免的)海啸做准备。

    Summary
    ::摘要

    • People love the shore, so they develop these regions and then must protect them.
      ::人们热爱岸边,所以他们发展这些区域,然后必须保护他们。
    • Seawalls and breakwaters are built parallel to the shore.
      ::防波堤和防波堤与海岸平行建造。
    • Groins are built perpendicular to the shore. They trap sand.
      ::草根建在与海岸垂直的地上,它们捕捉沙子。

    Review
    ::回顾

    1. How does a groin protect a beach?
      ::腹股沟如何保护海滩?
    1. How does a seawall protect a beach?
      ::海堤如何保护海滩?
    1. How does a breakwater protect a beach?
      ::防波堤如何保护海滩?
    1. What are the downsides of protecting beaches with engineering solutions?
      ::用工程解决方案保护海滩的不利之处何在?

    Explore More
    ::探索更多

    Use the resource below to answer the questions that follow.
    ::利用以下资源回答以下问题。

    1. What are the two methods to slow down coastal erosion?
      ::减缓海岸侵蚀的两种方法是什么?
    1. What is a sea wall? What does it protect the shore from?
      ::什么是海墙?它能保护海岸不受什么影响?
    1. What is a jetty? What does it protect the shore from?
      ::什么是码头?它能保护海岸不受什么影响?
    1. What is a groin? What does it protect the shore from?
      ::什么是腹股沟?它能保护海岸不受什么影响?
    1. What are breakwaters? What do they protect the shore from?
      ::什么是防波堤?
    1. Why don't people like most of the methods to prevent coastal erosion?
      ::为什么人们不喜欢大多数防止海岸侵蚀的方法?
    1. What is beach nourishment?
      ::什么是海滩营养?
    1. What problems does beach nourishment cause?
      ::海滩营养有什么问题?