Environmental Studies Words from Environmental Geo
Terms
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- hydrologic cycle
- is the water in hydrosphere's movement in reservoirs in time from evaporation, precipatation and percolation. The biggest revorvoir in the hydrologic cycle is the ocean.
- drainage basin
- The region from which a stream draws water from. The quantity of water flowing into a stream depends upon the size of the drainage basin upstream from it.
- discharge
- is the volume of water flowing past a given point at a given time. The size of a stream depends on its discharge.
- base level
- is the lowest elevation to which a stream can erode downward. For most streams base level is the body of water into which they flow.
- meander
- a meander is a bend in the stream. once a meander forms it tends to enlarge and aslo to shift downstream.
- cut bank
- is the eroded outside of a meander. The water flows faster on the cut bank side of the meander.
- point bar
- consists of sediment deposited on the insides of a steam. Point bars build out the banks on the inside of meanders.
- stream gradient
- is the steepness of the stream channel. The higher the gradient, the steeper the channel is.
- oxbow lake
- is a cut off meander. To find a faster and more direct route, especially in times of flood, the stream may make a short cut, abandoning the old twisted route.
- flood plain
- is where the stream spills during floods. A flat expanse of land covered in sediment around the stream channel is the flood plain.
- delta
- is a fan shaped pile of sediment in a body of water (though usually found in the ocean.) deltas are formed from a river's deposited sediment.
- levees
- are raised banks along a stream channel. Hurricane Katrina caused so much damage because the levees broke.
- stage
- is the elevation of the water's surface at any given point. A stream is at flood stage when stream stage exceeds bank height.
- hydrograph
- is the plotted flunctuations of a stream. Hydrographs spanning long periods of time are very useful for forming a picture to a stream's response to floods.
- flood frequency interval
- is how frequently a flood of that severity occurs on average for that stream. A flood can be described by its recurrence interval.
- point source pollution
- is an identifiable source from which pollutants are released. Point sources include sewer outlets, steel mills and septic tanks.
- non point source pollutants
- is an unidentifiable source from which pollutants are released. They include run off from fertilizer, or acid drainage from an abandoned strip mine.
- biological oxygen demand or BOD
- of a system is the amount of oxygen required to breakdown organic matter aereobically. The BOD may far exceed the actuall amount of dissolved oxygen in the water.
- eutrophication
- is the development of excess fertilizer or other organic matter. Algal bloom usually accompanies or results from eutrophication.
- acid
- is a substance that donates H+. The most acideic number on the pH scale is 1. Acid rain is usually 5.6
- base
- is a substance that consmes H+. Th most acidic number on the pH scale is 14. Streams and lakes have a pH of 6-9.
- the pH scale
- measures acidic and alkaline quality of liquid. The most neutral number on the pH scale is 7.
- Acid Neutralizing capacity or ANC
- measures how much hydrogen or H+ a body of water can neutralize before it becomes acidic. When a body of water is filled with acid rain, it uses its ANC to neutralize itself again.
- carbonic acid
- is a weak acid. It is found in slightly acidic rivers.
- sulfuric acid
- is produced from coal manufactoring. It is strong and highly corrosive and effects fish and forests.
- nitric acid
- is produced from combustion of fuel and organic matter. It is irritant and corrosive. It causes eutrophication and effects human health.
- aquitard
-
is a rock that can store a considerable amount of water, but the water flow is slowed or retarded, that is it's permeability is low, regardless of its
porisity. - vadoze zone
- is the zone above the saturated zone consisting of rock or soil and filled with water and air. The vadose zone is key to agriculture productivity.
- pheatric zone
- is the saturated zone below the unsaturated zone consisting of impermable layers of rock and soil. It is fully saturated/
- permeability
- is a measure of how readily fluid can flow through material. Permeability is related to the size of pores and cracks in the material and to their quantity.
- water table
- is defined by the top of the saturated zone or pheatric zone. The water table is not always below the ground surface, but can intersect with a resulting lake, spring or wetland.
- calcite
- is a mineral found in limestone and marble. Ithas high poristy and permeability. It is suceptable to chemical weathering.
- feldspar
- is a mineral found in granite. It is slow in dissolving and less suceptable to chemical weathering.
- quartz
- is a mineral found in granite. It is the most resistant to chemical weathering.
- aquifer
- is rock or glacial deposit that holds enough water and transmites it rapidly to be a useful source of water. Some of the best aquifers are sandstones beause they are porous and permeable.
- porosity
- is the proportion of void space in the material and it measures how much fluid the material can store. Sponges have high porosity.
- potentiometric surface
- is the height to which the water's pressure would raise the water if the water were unconfined. The potentiometric surface can be the ground water.
- artisian well
- is a well drilled into an unconfined aquifer. The water in an artesian well can raise above its level in the aquifer because of fluid pressure.
- confined aquifer
- is bounded above and below by low permeability rocks. Water in a confined aquifer may be under considerable pressure from adjacent rocks.
- unconfined aquifer
- is an aquifer directly overlain with permeable rocks and soil. An unconfined aquifer may be recharged throuh infiltration since it is not a sectioned off surface.