last week we discussed how run-off can occur two different ways: surface run-off – water flowing...
TRANSCRIPT
WATER BENEATH THE SURFACE
Last week… Last week we discussed how run-off
can occur two different ways: Surface Run-off – water flowing on
the surface to streams, rivers and oceans.
Subsurface Run-off – water absorbed by and flowing under the ground. It still flows back to oceans.
Vocabulary
Aeration Zone – the zone that lies between the water table and the Earth’s surface
Saturation Zone – The layer of an aquifer where the pore space is completely filled with water.
Water Table – the boundary line of the
zone of saturation.
Infiltration Infiltration is the process of water
entering the soil. Since water has infiltrated (entered) the
soil, it is considered groundwater.
Porosity & PermeabilityPOROSITY PERMEABILITY
Groundwater seeps down through the soil and fills the pores, or spaces between rock particles.
Porosity is the indicator of how much groundwater those pores can store.
Sometimes the pores in the ground are connected to each other.
Permeability is the ease that water can pass through a porous material.
A substance is impermeable if water cannot flow through it.
Porosity
Which picture shows greater porosity? Which picture shows lesser porosity?
Permeability
Which picture shows the most permeability?
Which picture shows the least permeability?
Aquifers An underground body of rock or sediment
where large amounts of water can flow and be stored is called an aquifer.
Groundwater Diagram
Wells and Springs
Wells and Springs
A WELL is a manmade hole dug in order to access groundwater.
It is manmade, so it is not natural.
A SPRING is a place where the water table naturally meets the ground’s surface.
It is a natural flowing of water from a natural hole in the ground.
Wells and Springs
Wells and springs are divided into two groups – Ordinary
- Artesian
Ordinary
ORDINARY WELL ORDINARY SPRING
An ordinary well is a hole that is dug below the water table to bring groundwater to the surface
An ordinary spring is a natural flowing of groundwater out onto the surface
Artesian
ARTESIAN WELL ARTESIAN SPRING
A manmade hole where water flows freely without being pumped
Water flowing through cracks in impermeable rock