Section outline

  • General

    Collapse all Expand all

  • 水循环

    Portrait of George Washington, first President of the United States, looking directly at the viewer.

    Could you be drinking the same water as George Washington?
    ::你能和乔治·华盛顿喝同样的水吗?

    Water is recycled constantly through the . That means any water you drank today has been around for millions of years. You could be drinking water that was once drunk by George Washington, the first humans, or even the dinosaurs .
    ::水不断通过水循环循环。这意味着你今天喝的任何水都已经存在数百万年了。你可能喝过曾经被第一位人类乔治·华盛顿(George Washington)甚至恐龙喝过的水。

    The Water Cycle
    ::水循环

    Whereas energy flows through an ecosystem, water and elements like carbon and nitrogen are recycled. Water and nutrients are constantly being recycled through the environment. This process through which water or a chemical element is continuously recycled in an ecosystem is called a biogeochemical cycle . This recycling process involves both the living organisms (biotic components) and nonliving things (abiotic factors) in the ecosystem. Through biogeochemical cycles, water and other chemical elements are constantly being passed through living organisms to non-living matter and back again, over and over. Three important biogeochemical cycles are the water cycle , , and .
    ::水和养分不断通过环境循环利用。通过这一过程,水或化学元素在生态系统中不断循环利用,这被称为生物地球化学循环。这种循环利用过程涉及生态系统中生物生物体(生物成分)和非生物物质(非生物因素),通过生物地球化学循环,水和其他化学元素不断通过生物生物体传入非生物物质,反复或重复。三种重要的生物地球化学循环是水循环。

    The biogeochemical cycle that recycles water is the water cycle. The water cycle involves a series of interconnected pathways involving both the biotic and abiotic components of the . Water is obviously an extremely important aspect of every ecosystem. Life cannot exist without water. Many organisms contain a large amount of water in their bodies, and many live in water, so the water cycle is essential to life on Earth. Water continuously moves between living organisms, such as plants, and non-living things, such as clouds, rivers, and oceans ( Figure ).
    ::循环利用水的生物地球化学循环是水循环,水循环涉及一系列相互关联的途径,涉及水的生物和非生物组成部分。水显然是每个生态系统的一个极为重要的方面。没有水,生命就不可能存在。许多生物体体内含有大量水,许多生活在水中,因此水循环对地球上的生命至关重要。水在植物等生物体与云、河流和海洋等非生物体之间不断移动(图 )。

    The water cycle does not have a real starting or ending point. It is an endless recycling process that involves the oceans, lakes and other bodies of water, as well as the land surfaces and the atmosphere . The steps in the water cycle are as follows, starting with the water in the oceans:
    ::水循环没有真正的起点或终点,它是一个无休止的循环利用过程,涉及海洋、湖泊和其他水体,以及陆地表面和大气。

    1. Water evaporates from the surface of the oceans, leaving behind salts. As the water vapor rises, it collects and is stored in clouds.
      ::海水从海洋表面蒸发,留下盐类,随着水蒸发,水会聚集并储存在云中。
    2. As water cools in the clouds, condensation occurs. Condensation is when gases turn back into liquids.
      ::当水在云中冷却时,会发生凝结。凝结是指气体再变成液体时。
    3. Condensation creates precipitation . Precipitation includes rain, snow, hail, and sleet. The precipitation allows the water to return again to the Earth’s surface.
      ::降水导致降水。 降水包括雨水、积雪、冰雹和流水。 降水使水能再次回到地球表面。
    4. When precipitation lands on land, the water can sink into the ground to become part of our underground water reserves, also known as groundwater . Much of this underground water is stored in aquifers , which are porous layers of rock that can hold water.
      ::当降水降落在陆地上时,水会沉入地下,成为我们地下水储备的一部分,也称为地下水,这些地下水大部分储存在含水层中,含水层是多孔的岩层,可以蓄水。

    Run-off
    ::径流

    Most precipitation that occurs over land, however, is not absorbed by the soil and is called runoff . This runoff collects in streams and rivers and eventually flows back into the ocean.
    ::然而,在陆地上发生的大部分降水没有被土壤吸收,被称为径流,这种径流聚集在溪流和河流中,最终流入海洋。

    Transpiration
    ::追踪

    Water also moves through the living organisms in an ecosystem. Plants soak up large amounts of water through their roots . The water then moves up the plant and evaporates from the leaves in a process called transpiration . The process of transpiration, like evaporation , returns water back into the atmosphere.
    ::植物通过根部吸收大量水,然后将水从叶子中蒸发。 蒸发过程,如蒸发,将水带回大气中。

    The water cycle, showing processes like evaporation, condensation, and runoff.

    The water cycle.
    ::水循环。

    Science Friday : Can Underwater Parks Protect Coral?
    ::科学星期五:水下公园能保护珊瑚吗?

    Coral communities are incredibly important for marine life. In this video by Science Friday , Marine scientists John Bruno and Elizabeth Selig describe the effects of local Marine Protection Areas on preserving coral.
    ::珊瑚群对海洋生物至关重要。 在科学星期五的这段视频中,海洋科学家约翰·布鲁诺和伊丽莎白·塞利格描述了当地海洋保护区对保护珊瑚的影响。

     

    Summary
    ::摘要

    • Chemical elements and water are constantly recycled in the ecosystem through biogeochemical cycles.
      ::化学元素和水通过生物地球化学循环在生态系统中不断回收。
    • During the water cycle, water enters the atmosphere by evaporation and transpiration, and water returns to land by precipitation.
      ::在水循环期间,水通过蒸发和蒸发进入大气,水通过降水返回土地。

    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。

    • The Water Cycle at (2:48)
      ::水循环(2:48)
    1. What is a fundamental difference between the water cycle and other nutrient cycles?
      ::水循环和其他养分循环之间的根本区别是什么?
    2. What drives the water cycle? Where does this process primarily occur?
      ::是什么驱动水循环? 这一过程主要发生在哪里?
    3. What happens to most of the water taken up by plants? How does this compare to most of the water taken up by animals?
      ::植物取水的大部分情况如何?这与动物取水的大部分相比如何?
    4. How does water's role in photosynthesis explain increased biological productivity in areas of heavy precipitation?
      ::水在光合作用中的作用如何解释大量降水地区生物生产力提高的原因?

    Review
    ::回顾

    1. What is the water cycle?
      ::什么是水循环?
    2. What are two ways water returns to the atmosphere?
      ::水返回大气层的两种方式是什么?
    3. How does water get from the atmosphere back to land? What are the various forms of this process?
      ::水是如何从大气层流回陆地的?这一过程的各种形式是什么?
    4. What is the relationship between groundwater and aquifers?
      ::地下水与含水层之间的关系是什么?