Water Crisis PDF

Ch. 10 The Water Crisis 1.​ Soil retention structures a.​ Soil retention measures are structures or practices that hold soil in place or keep it contained within a site boundary. They can include grading or reshaping the ground to lessen steep slopes but most com...

Ch. 10 The Water Crisis 1.​ Soil retention structures a.​ Soil retention measures are structures or practices that hold soil in place or keep it contained within a site boundary. They can include grading or reshaping the ground to lessen steep slopes but most commonly include shoring excavated areas with wood, concrete or steel structures. 2.​ Fresh water amount vs total water on Earth a.​ Only 2% of earth’s water is freshwater 3.​ Liquid water vs ice and snow a.​ 87% ice and snow. 13% is liquid water 4.​ Surface water a.​ Water found in lakes and streams represents only a minuscule fraction, amounting to less than 0.5% of the total freshwater reservoir 5.​ Closed system a.​ No matter enters or leaves, energy flows in and out 6.​ Hydrologic cycle a.​ Water moves, continually cycling both around and through the earth as water vapor, liquid water, and ice. 7.​ Variation in availability of freshwater a.​ Varies significantly across the globe due to natural variations in geography and climate 8.​ Orographic rainfall a.​ Mountain-induced precipitation b.​ Access to water is more complicated than whether you simply receive adequate rainfall levels 9.​ Groundwater a.​ When water seeps into the ground 10.​Zone of aeration a.​ Layer of soil near the surface where the pores (spaces) between soil particles are filled with both water and air; serves as the primary source of water for most vegetation 11.​Zone of saturation a.​ When the water reaches an area where there is no longer any air present in the pores 12.​Water table a.​ Boundary between the zone of aeration and the zone of saturation 13.​Aquifer a.​ When underground water is held in permeable rock in quantities that make it a significant water store b.​ Categorized as either unconfined or confined 14.​Confined aquifer a.​ Characterized by water being pressurized between two confining layers of very low permeability, known as aquitard i.​ Aquitard: impermeable layer that hinders or prevents water movement  ii.​ Aquifer: permeable rock of sediment that transmits groundwater freely 15.​Unconfined aquifer a.​ Is defined by the water table as its upper surface, nad groundwater within it is replenished directly by infiltrating rainfall 16.​Recharge a.​ Over-pumping occurs when the amount of water extracted from an aquifer exceeds the volume replenished through recharge; when it occurs the water table of the aquifer is lowered 17.​Drawdown a.​ Vertical disparity between the original qatar table elevation and lowered table is termed drawdown 18.​High Plains Aquifer a.​ Underlies an area of about 174000 square miles 19.​Consequences of over-pumping a.​ Ground subsidence b.​ Ground contamination c.​ Salt intrusion 20.​Ground subsidence a.​ Reduction in fluid pressure in the pores and cracks of aquifers causes overlying rocks to compact the sediments, resulting in a lowering of the land surface 21.​Groundwater contamination: a.​ Seawater naturally extends beneath land, but typically remains greater depths than freshwater due to its higher density 22.​Saltwater intrusion a.​ often occurs in coal areas through a process termed saltwater intrusion when freshwater is withdrawn from an unconfined coastal groundwater basin 23.​How much water do we use in the U.S.? a.​ 322 billion gallons per day 24.​Is more freshwater withdrawal from surface water or groundwater? a.​ More surface water than groundwater has been utilized for irrigation, but this trend is changing 25.​Most water withdrawal (42%) is for; a.​ Thermoelectric power 26.​2nd largest water withdrawal (37%) is for: a.​ Irrigation 27.​U.S. states with highest water withdrawal a.​ California b.​ Texas c.​ Idaho d.​ Florida 28.​Direct water a.​ Bathing, cooking, drinking 29.​Indirect (virtual) water a.​ Water used to produce goods and services 30.​Minimum water required for basic needs a.​ WHO suggests that a minimum of 5 gallons of water per day is needed to meet a person’s basic needs for drinking, sanitation, bathing, and cooking 31.​Average American water use per day a.​ Average american uses 155 gallons of water per day 32.​U.S. Clean Water Act a.​ Enacted by U.S. congress in 1972 to safeguard the quality of our water 33.​How are we doing today compared to 1972? a.​ Today more than ⅔ of water if safe for swimming and fishing b.​ Wetland losses decreased to 80000 acres annually c.​ Agricultural runoff causes less than 1 billion tons of topsoil loss annually d.​ Sewage treatment plants serve over 250 million people e.​ We are doing better than we were in 1972 34.​Point source pollution a.​ Effluent being released from a single outlet; generally easier to monitor and control 35.​Effluent a.​ Water mixed with waste matter 36.​Nonpoint source pollution a.​ Cannot be linked to one specific source, such as when runoff picks up pollutants from agricultural fields. 37.​Sediment pollution a.​ Are the main concern b.​ Loose particles of sand, clay, and silt c.​ Originate from erosion processes where soil is removed by wind or water 38.​Turbidity a.​ Cloudiness of water 39.​Bioaccumulation a.​ Organisms that live at the bottom of the stream (benthic) can ingest pollutants, which can be absorbed in their tissues (bioaccumulation) 40.​Biomagnification a.​ The movement and concentration of pollutants within a food chain is called biomagnification 41.​Wastewater/sewage pollution a.​ The UN estimates that more than 80% of the world’s wastewater flows back into the environment without being treated. In developing nations, that figure exceeds 95%. This means that human waste, household sewage, and sometimes toxic and even medical waste, are released directly into the planet’s ecosystems 42.​Dissolved oxygen (DO)  a.​ The most important characteristic determining the quality of a river or stream is its dissolved oxygen 43.​Ideal DO is _____ ppm a.​ A stream is generally considered healthy as long as its DO exceeds 5 ppm; below that, most fish do not survive. 44.​Oxygen deficit DO is _____ ppm a.​ Bacteria decompose the organic matter in the sewage and DO levels fall, reaching a maximum “oxygen deficit” when DO levels reach approximately 2 ppm 45.​Nutrient pollution a.​ Polluted runoff containing nutrients can originate from various sources: agricultural fertilizers, septic systems, household lawn care products, yard and animal waste 46.​Nitrogen a.​ nutrients like nitrogen which is essential for an organism’s metabolism 47.​Eutrophication a.​ Surplus nutrients seep from soil into groundwater and surface waters, triggering the overgrowth of aquatic plants leading to algal blooms 48.​Hypoxia a.​ Aas algae die off and are decomposed by bacteria, oxygen in the water drops to levels that can be deadly for many marine organisms 49.​Dead zones a.​ Large areas of hypoxia=dead zone; oxygen levels are so depleted that fish and other aquatic organisms cannot survive 50.​Gulf of Mexico a.​ Largest of the dead zones occurs annually in the gulf of mexico, spanning up 20,000 square kilometers 51.​Any other contaminants in water of concern? a.​ In addition to sediment, sewage, and nutrient, there is pesticide, pharmaceuticals, polychlorinated biphenyls (PCBs), volatile organic compounds, (VOCs), and potentially hazardous trace elements 52.​Plastic pollution a.​ Is emerging as a significant environmental challenge 53.​Great Pacific Garbage Patch ​ A huge area of floating trash in the north pacific ocean. Mostly made of plastic 54.​Watershed approach a.​ Involves considering not just the water body itself but also the entire area that contributes to runoff to it, it allows communities to focus on the most serious water concerns within an area 55.​What watershed do you live in? a.​ Trinity HUC 12030102 (Trinity R, W FK)