Term
| Drainage basin / watershed |
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Definition
| water-collecting area that feeds a stream, land surface area drained by a particular stream and its tributaries |
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Definition
| assessment of whether or not a specific drainage basin and its subsurface groundwater system has gained or lost water over a period of time |
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Definition
calculation of changes in mass of water in a drainage basin (flux) or movement across boundaries
INPUTS = OUTPUTS + CHANGE IN VOLUME |
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Definition
| raingall running across surface as surface flow - sheets, distinct channels |
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Definition
| constant movement of water |
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Term
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Definition
any surface water whose flow is confined to a channel
maintained by:
1. PRECIPITATION THAT FALLS ON LAND AND RUNS OFF INTO STREAM
2. BASEFLOW |
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Term
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Definition
| underground water system that feeds a stream - allows streams to flow in times of drought with no runoff |
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Definition
| network of smaller streams feeding a larger one |
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Definition
| area of higher topography bounding a drainage basin area, dividing one from another |
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Definition
| small channels branching off of a stream |
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Definition
| slope of a stream (vertical drop over horizontal distance) |
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Definition
- SLOWEST at sides and bottom of stream because friction between water and channel
- GREATEST in center of stream in a straight segment - least amount of friction from either atmosphere or stream bed |
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Definition
| volume of water passing a given point on the stream bank per unit of time |
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Term
| Properties of ground in terms of groundwater system |
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Definition
| porosity, permeability/hydraulic conductivity |
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Term
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Definition
decimal % of rock/sediment by volume that is pore space (n)
n = volume of voids / total volume of rock |
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Definition
ease with which fluid passes through rock or sediment (K)
DEPENDS ON:
1. fluid type
2. temperature
3. SIZE OF VOIDS
4. HOW CONNECTED THE VOIDS ARE
(MORE IMPORTANT THAN POROSITY because even if a rock is not very porous, pores may still be very interconnected and easily able to circulate water) |
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Term
| Layers of Groundwater system |
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Definition
1. Land surface
2. Unsaturated area / Vadose zone / Zone of Aeration - pores not (entirely) filled with water
3. Water table - Phreatic surface, dividing line at beneath which all pores are filled with water
4. Saturated / Phreatic Zone - lots of pressure, movement of water in all directions, not just subject to gravity |
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Term
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Definition
| region just above water table in which attraction between water molecules and themselves and the mineral surface allows a little bit of water to be creep up into the zone of aeration |
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Term
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Definition
the combined influences of gravity and water pressure on groundwater flow at a given depth
- Groundwater moves from an area of HIGH POTENTIAL (high spots in water tables under hills) to LOW POTENTIAL (low spots in water tables under valleys) |
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Term
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Definition
difference in potentials of 2 points divided by the lateral distance between the points
- partially controls flow rate |
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Definition
a way to quantify permeability of a rock, sediment, or soil - reflects sizes, shapes, and degree of sorting of grains
high conductivity - coarse (large-grained), well-rounded, well-sorted
low conductivity - fine (small-grained), angular, poorly-sorted |
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Term
| Property of groundwater that makes it available for human use |
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Definition
| slow speed with which it travels underground |
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Term
| To determine depth of a water table... |
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Definition
| dig a hole or drill a well, dummy |
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Term
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Definition
| SATURATED body of rock, or very permeable bodies of rock, sediment, or soil that transmit groundwater readily, underground bodies from which we withdraw the water we use to meet our domestic, agricultural, and industrial needs |
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Definition
| aquifers extending nearly to the Earth's surface - with no beds of impermeable rock above them - top of aquifer is AT the water table |
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Definition
| water transmitting layers of rock sandwiched between other rock layers that are IMPERMEABLE of have VERY LOW PERMEABILITY (AQUITARDS) - top of aqifer is AT THE BASE OF OVERLYING AQUITARD |
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Definition
| surface water seeping into unsaturated zone (soil moisture) |
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Definition
| infiltrating water that joins groundwater system in water table |
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Definition
| infiltrating water that flows into ground surface and COMES OUT IN STREAMS AND RIVERS (baseflow) |
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Definition
| water lost from groundwater system by going up in roots of plants and evaporating into atmosphere from leaves |
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Term
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Definition
- permeability (cracks, sediment type - if it's more permeable, more infiltration)
- rain intensity (runoff when water intensity is too high, water piles up and doesn't seep in)
- ground condition (runoff if frozen, saturated)
- steepness of slope (elevation difference = relief)
- density of & type of vegetation (prevents runoff by slowing down water reaching ground, allowing it to infiltrate)
- climate
- land use (asphalt vs. forest) |
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Term
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Definition
| in a saturated body of rock when water will rise in a piezometer ABOVE THE TOP OF THE BODY OF ROCK - above the WATER TABLE in a unconfined aquifer, above the top surface of a confined aquifer - determined by PRESSURE |
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Term
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Definition
| Precipitation (P) = Evapotranspiration (Et) + Surface water flow out from stream (Q) + Change in Volume (Sgw - change in level of water table over a given time) |
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Term
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Definition
| rare saturated body of rock that has NO permeability - closed off body of water |
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Term
| Flowing Artesian Condition |
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Definition
| in a saturated body of rock when WATER WILL RISE IN PIEZOMETER ABOVE LAND SURFACE |
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Definition
| way to measure (TOTAL) HEAD, ELEVATION HEAD, PRESSURE HEAD - hollowed out pipe inserted into zone of saturation, open at top and bottom and HAS NO OTHER OPENINGS |
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Term
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Definition
elevation to which water will RISE in a piezometer above something - usually sea level
H = Z + P |
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Term
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Definition
elevation of the bottom of the piezometer above whatever level is chosen to measure from (usually sea level)
Z |
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Term
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Definition
height of a column of water in a PIEZOMETER that will balance the pressure (HEIGHT important)
P
P at water table = 0 |
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Term
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Definition
| the level to which water would rise in a tall pipe in the HYPOTHETICAL ABSENCE of friction |
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Definition
| drawing down of water table level with pumping of wells - changes head conditions at surface, pushes water down towards well - if pumping rate is too high water table will drop below well and well will dry up! |
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Definition
| in coastal areas - pumping & reduced recharge leads to DROP in water table - leads to REDUCED PRESSURE in subsurface - salt water moves UP in reduced pressure, starts to come into wells! |
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Term
| In natural groundwater chemistry we look at... |
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Definition
1. Dissolved solids (ions - cations and anions in solution)
cations: NA+, K+, Mg2+, Ca2+, H+
anions: Cl-, HCO3-, CO3-2, SO4-2, OH-
2. Dissolved gasses
CO2, O2, SO2, H2S, CH4, NH3
3. Electroneutrality - all natural solutions have a charge balance (tests for charge of water, shows high concentrations of dissolved things - water should be balanced)
4. other dissolved things - IRON creates brown/orange sink stains as it oxidizes when it hits oxygen, SULFUR if there's lots of iron - very acidic and bad to drink, LEAD - usually comes from old pipes, ARSENIC |
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Term
| TDS - Total Dissolved Solids |
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Definition
[#] in mg/L - test that measures the concentration of the total of all the dissolved ions
- rain (low TDS) 0 - 25
- fresh groundwater 300-500 mg/L
- streams 100-400 mg/L |
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Term
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Definition
way to classify water
freshwater 0-1,000 TDS
brackish water 1,000-10,000 TDS (fresh & salt)
saltwater 10,000-100,000 TDS (ocean has about 35,000)
brine > 100,000 TDS |
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Term
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Definition
dissolved or released by chemical reactions with sediment, rocks, and soils (chemical weathering)
CONCENTRATION determined by:
1. time/distance of flow in contact wit rocks & minerals
2. types of rocks & minerals its going through
3. conditions (temp, pressure, acidity, oxygen levels) |
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Definition
| energy from Earth's interior (hot springs & geysers) |
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Term
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Definition
- water in subsurface boils and expands and shoots out
- groundwater adjacent to subsurface system fills in where water was
- coming in cool and getting heated up under lots of pressure
- boiling point raises from pressure
- when it is reached it boils
- steam forms
- pressure drops and lowers boiling point
- now tons of water above boiling point
- erupts as steam all at once |
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