Chapter 15: Groundwater and Karst

Groundwater model

soil-water belt

unsaturated zone

groundwater zone/ saturated zone

water table

the top of the saturated zone

porosity

having minute spaces through which liquid or air may pass

permeability

state or quality that allows liquids or gases to pass through

low porosity and impermeable

no pore spaces and no way for water to be transmitted

slightly porous and impermeable

contains pore spaces and no way for water to be transmitted

porous and permeable

many large pore spaces and pores are connected, water can be transmitted through the pores

Aquifer

geological information containing significant water- storage

aquiclude

impermeable rock that does not allow transmission of water

recharge area

the location where surface water infiltrates the ground and replenishes an aquifer

Springs

where water seeps out naturally

artisan wells

water from confined aquifer can rise toward the surface because of pressure on aquifer

cone depression

built wells, irrigation. as water is pumped out of a saturated zone, water table lowers. if water is pumped out faster than can migrate in, a cone of depression developes

groundwater change

irrigation and water use is much higher than recharge rate

land subsidence

pore spaces grow/shrink with fluid availability

too much removal, permanent shrinkage of pore space

Karst landforms

where soluble rocks have dissolved, leaving a distinct topography

requirements for a karst landscape

groundwater, soluble rock, chemical weathering

caves

large cavities in the rock formation. a system of caves is caverns

why do sinkholes form in karst landscapes?

if the rock underground dissolves and the surface can’t be supported

tower karst

tall rock structures made up of soluble rock such as limestone