Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
10 Cards in this Set
- Front
- Back
|
What is the belt of soil moisture?
|
- the near surface zone that is composed of water that soaks in but does not travel far due to molecular attraction.
- this surface film is also supported by roots and animal and worm burrows. |
|
|
What is the zone of saturation?
|
- water that percolates downward until it reaches a zone where all of the open spaces in sediment are completely filled with water.
- water within this zone is called groundwater |
|
|
What is the zone of aeration?
|
- it is the area above the water table that includes the capillary fringe and the belt of soil moisture.
- water cannot be withdrawn from this zone. |
|
|
Which rocks have the greatest porosity?
|
- rocks with sediments of various sizes generally have a lower porosity since the smaller sediments fill the spaces of the larger sediments.
- igneous and metamorphic rock tend to have minimal porosity since they are composed of tightly interlocking crystals. |
|
|
What is specific yield and specific retention?
|
- specific yield is the amount of water actually available for us whereas specific retention indicates how much water is bound to its material.
|
|
|
What is an aquitard?
|
- impermeable layers that prevent water movement.
- an example is clay, it has a high porosity, but a low specific yield and a high specific retention. |
|
|
Which way does groundwater move?
|
- since gravity is the driving force of groundwater, water moves from areas of high zones to low zones.
- meaning it gravitates towards a stream or lake. - water tends to migrate toward points of lower pressure. |
|
|
What is groundwater used for?
|
1) 65% of groundwater is used as irrigation for agriculture.
2) industrial 3) city water systems and rural homes. |
|
|
what is a cone of depression?
|
- when water is withdrawn from a well, the water table is lowered below it.
- the drawdown decreases as it moves away from the well resulting in a cone of depression. - this will lower the water table and cause nearby wells to become dry. |
|
|
What is subsidence?
|
- as water is withdrawn, the water pressure drops and the weight of the overburden is dropped onto the sediments, cause an increase in pressure of the grains, leading to the ground subsiding.
|
