Final Flashcards
Groundwater is the largest reservoir of ______ that is readily available to humans
Freshwater
6/10 of __ percent of the hydrosphere is groundwater
1
Groundwater % out of all water
14.6%
Groundwater % out of all liquid freshwater
94.05%
Groundwater acts as an erosional agent dissolving soluble _______ such as ______.
bedrock
Limestone
Most groundwater soaks into the ground from _________.
Precipitation
Zone of soil moisture
Zone where water is held by molecular attraction on soil particles in the near-surface zone
Used by plants
Evaporates directly back into the atmosphere
Zone of saturation
Zone where all the pore spaces are completely filled with water
Water table
Upper limit of the zone of saturation
Unsaturated zone (vadose zone)
Area above the zone of saturation
Pore spaces include air and water
Capillary fringe
Region where groundwater is held in pore spaces by surface tension
Interaction between groundwater and streams constitutes a basic link in the ________ cycle.
Hydrological
Gaining streams
Gain water from the inflow of groundwater through the stream bed
Water table is higher than the stream surface
Losing streams
Lose water to the groundwater system by outflow through the stream bed
Water table is lower than the stream surface
Losing stream becomes disconnected by the ____ _____, and a bulge may form in the water table.
Unsaturated zone
Porosity
The percentage of pore(open) spaces in a rock or sediment
______ depends on the size and shape of the grains, how we’ll they are sorted, and how tightly they are packed
Porosity
_____ determines how much groundwater can be stored.
Porosity
Ability of a material to transmit a fluid
Permeability
_____ is an impermeable layer that hinders or presents water movement and is usually clay
Aquitard
______ is permeable rock strata or sediment that transmits groundwater freely
Aquifer
Examples: sands and gravels
Groundwater moves very _____.
Slowly ; 4 cm per day
A simple groundwater flow system
The force of gravity and pressure differences move groundwater
In a simple groundwater system, Groundwater is replenished in areas of _____.
Recharge
In a simple groundwater flow system, groundwater flows back to the surface in a ____ ____.
Discharge area
Darcy’s Law
Measure of the volume of Atwater that flows through an aquifer, using the hydraulic gradient, conductivity, and cross-sectional area
______ is the water table slope
Hydronic gradient
______ _____ takes into account the permeability of the aquifer and viscosity of the liquid to determine how fast water will flow through a medium
Hydronic conductivity
Hydraulic gradient formula
d
A ____ is a hole bored into the zone of saturation
Well
Drawdown
As water is withdrawn from the well, the surrounding water table is lowered
Cone of depression
Forms around a well
An ______ well or spring is a system where groundwater under pressure rises above the level of the aquifer
Artesian
Af aquifer confined by aquitards is called a _____ _____.
Confined aquifer
Non flowing artesian well
Pressure surface is below ground level
Flowing artesian well
Pressure surface is above the ground
A natural outflow of Atwater from the intersection of the water table and the ground surface is called a _____.
Spring
Water in hot springs is heated by what?
Cooling of igneous rock
Some by geothermal gradient
Intermittent hot springs in which columns of water erupt with force
Geysers
How do geysers work?
Occurs where extensive underground chambers exist within hot igneous rock
Groundwater heats, expands, changes to steam, and erupts
Geyser deposits
Chemical sedimentary rock accumulates at the surface
Type of rock reflects the ___ _____ of the bedrock
Chemical makeup
Mining groundwater
Treating groundwater as a non renewable resource
What is subsidence?
Example
The ground sinks when water is pumped from wells faster than natural recharge processes can replace it
San Joaquin valley of California
____ ____ is the excessive groundwater withdrawal causes saltwater to be drawn into wells, thus contaminating the freshwater supply
Saltwater contamination
Groundwater is often mildly _____.
Acidic
_____ acid reacts with ____ in limestone to form calcium bicarbonate, a soluble material.
Carbonic
Calcite
Caverns
Created by acidic groundwater dissolves limestone bedrock
About 17,000 caves in the US
When calcium carbonate deposited as dripping water evaporates, it is called ______.
Travertine
_____ is the general name for all dripstone features
Speleothem
Stalactites
Hanging from ceiling
Stalagmites
Form on the floor of a cavern
___ ____ is a landscape that has been shaped mainly by the dissolving power of groundwater.
Karst topography
Common features of Karst topography include:
Irregular terrain
Sinkholes
Striking lack of surface drainage
Zone of Aeration
All pore spaces are filled with air
Water is pulled up through ____ ____.
Capillary action
Losing stream that is connected provides water to the _____ _____.
Groundwater system
How can a stream be a combination of gaining and losing streams?
A stream can gain in some sections and lose in others
