Geology 1121 Ch.16

What is groundwater?

water that resides under earths surface mostly in pores or cracks of rocks or sediments

What is an aquifer?

saturated rock that holds and transmits groundwater

What makes for a good aquifer?

high porosity and permiability

What is porosity?

amount of empty space in a rock

Does well sorted or poorly sorted rock have better porosity?

well sorted (more space between rocks)

What is permiability?

ease of water movement through the rock

What is the groundwater table?

top of rocks saturated with water

What is the unsaturated zone?

rocks with limited water, not fully saturated

What is the saturated zone?

rocks fully saturated with water (aquifers)

What is the recharge zone?

area where the aquifer is renewed with water

What is an aquiclude?

impermeable layer, water will not pass through it (low porosity and permiability)

What is an unconfined aquifer?

aquifer near earths surface with an aquiclude below it

What is a confined aquifer?

pressurized aquifer with an aquiclude below and above it

What is the potentiometric surface?

the height to which water will rise in the confined aquifer

What is an artesian well?

a well with free-flowing water

Where are artesian wells installed?

in confined aquifers where the potentiometric surface is above earths surface

What is a perched aquifer?

small lens shaped water table with an aquiclude below

What is a well?

a hole dug by people to obtain groundwater

What is a base level?

low point in topography where water will flow

What is a cone of depression?

an area devoid of water from over pumping

What is recharge?

water that enters the ground through infiltration

What is discharge?

water that leaves the ground

What is a spring?

a natural outlet for groundwater flow