Global water resources and use
- 1. Group 2 : Eight Legged Freaks’
- 2. Over 70% of our Earth's surface is covered by water ( we should really call our planet "Ocean" instead of "Earth"). Although water is seemingly abundant, the real issue is the amount of fresh water available. 97.5% of all water on Earth is salt water, leaving only 2.5% as fresh water Nearly 70% of that fresh water is frozen in the icecaps of Antarctica and Greenland; most of the remainder is present as soil moisture, or lies in deep underground aquifers as groundwater not accessible to human use. < 1% of the world's fresh water (~0.007% of all water on earth) is accessible for direct human uses. This is the water found in lakes, rivers, reservoirs and those underground sources that are shallow enough to be tapped at an affordable cost. Only this amount is regularly renewed by rain and snowfall, and is therefore available on a sustainable basis.
- 4. * ●12,000 yrs. ago: hunter-gatherers continually return to fertile river valleys ● 7,000 yrs. ago: water shortages spur humans to invent irrigation ● 1,100 yrs ago: collapse of Mayan civilization due to drought ● Mid 1800's: fecal contamination of surface water causes severe health problems (typhoid, cholera) in some major North American cities, notably Chicago ● 1858: "Year of the Great Stink" in London, due to sewage and wastes in Thames ● Late 1800s-early 1900: Dams became popular as a water management tool ● 1900s: The green revolution strengthens human dependency on irrigation for agriculture ● World War II: water quality impacted by industrial and agricultural chemicals ● 1972: Clean Water Act passed; humans recognize need to protect water
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- 7. water ice sheets ice caps glaciers icebergs bogs ponds lakes rivers groundwater aquifers concentrations solids water chalybeate salts Earth streams total dissolved seawater brackish salt water According to WIKIPEDIA
- 9. * Earth Apollo 17 Antarctic ice sheet
- 10. * soil infiltrated water rain meltwater water cycle water erosion Runoff that occur on surfaces before reaching a channel is also called a nonpoint source.
- 12. * drainage basin
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- 16. * A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. An aquifer is an underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology.
- 18. The freshwater biome is made up of any of body of water that is made of freshwater such as lakes, ponds, streams, and rivers. They cover roughly 20% of the Earth and are in various locations spread out all over the world. Most freshwater biomes consist of moving water and contain many types of fish. *
- 20. body of water current bed stream banks watercourse ocean lake freshwater sea
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- 23. * water seas Saline water Brackish water Seawater Saline (medicine) oceans
- 24. Seawater is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, or 599 mM). Seawater is denser than both fresh water and pure water because the dissolved salts add mass without contributing significantly to the volume. The freezing point of seawater decreases as salt concentration increases. The coldest seawater ever recorded (in a liquid state) was in 2010, in a stream under an Antarctic glacier, and measured−2.6 °C (27.3 °F).