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  2. Sand mining - Wikipedia

    en.wikipedia.org/wiki/Sand_mining

    A process known as elutriation is used, whereby flowing water separates the grains based on their size, shape, and density. Sand mining is a direct cause of erosion, and impacts the local wildlife. [6] Various animals depend on sandy beaches for nesting clutches, and mining has led to the near extinction of gharials (a species of crocodilian ...

  3. Sand dam - Wikipedia

    en.wikipedia.org/wiki/Sand_dam

    A sand dam is a reinforced concrete wall (or a similarly robust and impermeable weir) built 1–5 metres high across a seasonal sand river.. When it rains the dam captures soil laden water behind it – the sand in the water sinks to the bottom, whilst the silt remains suspended in the water.

  4. Aquifer - Wikipedia

    en.wikipedia.org/wiki/Aquifer

    An aquifer is an underground layer of water-bearing material, consisting of permeable or fractured rock, or of unconsolidated materials (gravel, sand, or silt). Aquifers vary greatly in their characteristics. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology.

  5. Sand dredging is 'sterilising' ocean floor, UN warns - AOL

    www.aol.com/news/sand-dredging-sterilising-ocean...

    Sand is the most exploited natural resource in the world after water but its extraction for use in industries like construction is only loosely governed, prompting the U.N. to pass a resolution ...

  6. Groundwater recharge - Wikipedia

    en.wikipedia.org/wiki/Groundwater_recharge

    If water falls uniformly over a field such that field capacity of the soil is not exceeded, then negligible water percolates to groundwater. If instead water puddles in low-lying areas, the same water volume concentrated over a smaller area may exceed field capacity resulting in water that percolates down to recharge groundwater.

  7. Fracking - Wikipedia

    en.wikipedia.org/wiki/Fracking

    Hydraulic fracturing [a] is a well stimulation technique involving the fracturing of formations in bedrock by a pressurized liquid. The process involves the high-pressure injection of "fracking fluid" (primarily water, containing sand or other proppants suspended with the aid of thickening agents) into a wellbore to create cracks in the deep rock formations through which natural gas, petroleum ...

  8. Quicksand - Wikipedia

    en.wikipedia.org/wiki/Quicksand

    Quicksand (also known as sinking sand) is a colloid consisting of fine granular material (such as sand, silt or clay) and water. It forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight. Quicksand can form in standing ...

  9. Greensand - Wikipedia

    en.wikipedia.org/wiki/Greensand

    Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-layer clay minerals, such as smectite and glauconite. Greensand is also ...