Chapter 15 - Freshwater Systems and Resources Flashcards
watershed
the entire area of land from which water drains into a given river
water table
the upper limit of groundwater held in an aquifer
unconfined aquifer
a water-bearing, porous layer of rock, sand, or gravel that lies atop a less-permeable substrate. The water in an unconfined aquifer is not under pressure because there is no impermeable upper layer to confine it.
confined (artesian) aquifer
a water-bearing, porous layer of rock, sand, or gravel that is trapped between an upper and lower layer of less-permeable substrate, such as clay. The water in a confined aquifer is under pressure because it is trapped between to impermeable layers.
ground water
water held in aquifers underground
surface water
water located atop Earth’s surface
floodplain
the region of land over which a river has historically wandered and periodically floods
wetland
a system in which the soil is saturated with water that generally features shallow standing water with ample vegetation. these biologically productive systems include fresh water marshes, swamps, bogs, and seasonal wetlands such as vernal pools
dam
any obstruction placed in a river of stream to block the flow of water so that water can be stored in a reservoir. dams are built to prevent floods, provide drinking water, facilitate irrigation and generate electricity
reservoir
(1) an artificial water body behind a dam that stores water for human use (2) a “pool”
flooding
the spillage of water over a river’s banks due to heavy rain or snowmelt
sinkhole
an area where the ground has given way with little warning as a result of subsidence caused by depletion of water from an aquifer
nonconsumptive use
fresh water use in which the water from a particular aquifer or surface body either is not removed or is removed only temporarily and then returned. the use of water to generate electricity in hydroelectric dams is an example
consumptive use
use of fresh water in which water is removed from a particular aquifer of surface body water and is not returned. irrigation for agriculture is an example.
desalination (desalinization)
the removal of salt from seawater
non-point source
a diffuse source of pollutants, often consisting of many small sources.
point source
a specific spot where large quantities of air pollutants or water pollutants are discharged
pollution
the release of matter or energy into the environment that causes undesirable affects for living organisms. pollution can be physical, chemical, or biological, and it can affect water, air, or soil
water pollution
the act of polluting water, or the condition of being polluted by water pollutants
septic system
a wastewater disposal method, common in rural areas, consisting of an underground tank and series of drainpipes. wastewater runs from the house to the tank, where solids precipitate out. the water proceeds downhill to a drain field of perforated pipes laid horizontally in f=gravel-filled trenches. where microbes decompose the remaining waste
primary treatment
a stage of wastewater treatment in which contaminants are physically removed. wastewater glows into tanks which sewage solids, grit, and particulate matter settle to the bottom. Greases and oils float to the surface and can be skimmed off
secondary treatment
a stage of wastewater treatment in which biological means are used to remove contaminants remaining after primary treatment. wastewater is stirred up in the presence of aerobic bacteria, which degrade organic pollutants in the water. the wastewater then passes to another settling tank, where remaining solids drift to the bottom
waste water
any water that is used in house holds, businesses industries, or public facilities and is drained or flushed down pipes, as well as the polluted runoff from streets and storm drains
