{"id":213680,"date":"2022-01-26T16:04:47","date_gmt":"2022-01-26T15:04:47","guid":{"rendered":"https:\/\/www.ferrovial.com\/?page_id=213680"},"modified":"2022-09-22T18:11:15","modified_gmt":"2022-09-22T16:11:15","slug":"groundwater","status":"publish","type":"page","link":"https:\/\/www.ferrovial.com\/en\/resources\/groundwater\/","title":{"rendered":"Groundwater"},"content":{"rendered":" \n \n
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  1. Ferrovial<\/a><\/li>\n
  2. Resources<\/a><\/li>\n \n <\/ol>\n\n <\/c-breadcrumb>\n \n
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    \n Groundwater <\/h1>\n <\/div>\n <\/m-final-content-header>\n\n \n\n\n
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    What is groundwater?<\/h2>\n\n\n\n

    Groundwater is water that’s found below the surface of the Earth and which forms primarily as a result of precipitation<\/strong>. Groundwater is located within a geological formation called an aquifer, which is permeable and allows a certain amount of water to be stored. <\/strong><\/p>\n\n\n\n

    These bodies of water cover over twenty times the total surface water of the continents and islands<\/strong>, and the largest ones can extend over more than a million square kilometers. This is why they’re a precious resource;<\/strong> according to UNESCO<\/a>, they are the source of half of all the drinking water in the world. <\/p>\n\n\n\n

    How does groundwater form?<\/h2>\n\n\n\n

    Groundwater responds to the water cycle. When precipitation occurs \u2014 whether rain or snow \u2014 the water that doesn’t evaporate percolates through the ground until it comes to a permeable rock (an aquifer) below the surface. That aquifer absorbs it like a sponge. <\/strong>Its porosity permits both the flow and the extraction of groundwater. <\/strong><\/p>\n\n\n\n

    An aquifer’s structure is classified into the following:<\/p>\n\n\n\n

    1. Aeration zone: <\/strong>the space between the surface and the water table \u2014the accumulation of groundwater at a low depth with respect to the ground\u2014 where not all the pores absorb water. <\/li>
    2. Saturation zone: <\/strong>located just above the impermeable layer of rock, whose pores are completely filled with water.<\/li><\/ol>\n\n\n\n

      How are aquifers where groundwater is found classified?<\/h2>\n\n\n\n
      1. Free:<\/strong> those that do not have an impermeable layer on top, so the water pressure is equal to atmospheric pressure <\/li>
      2. Confined:<\/strong> groundwater is between two impermeable layers; the pressure is greater than atmospheric pressure <\/li>
      3. Semi-confined:<\/strong> has characteristics between the free and confined varieties; its upper layer is not entirely waterproof, so water can be discharged and refilled. <\/li><\/ol>\n\n\n\n

        Why is groundwater important?<\/h2>\n\n\n\n

        In addition to being easy to find and resistant to drought,<\/strong> groundwater entails the largest reserve of freshwater on Earth.<\/strong><\/p>\n\n\n\n