Lesson 5: Groundwater flow to wells Flashcards
are used for the extraction of groundwater
water wells
groundwater is extracted to fill what 4 types of needs?
domestic, municipal, industrial and irrigation
what is done as means of groundwater management when wells are sometimes used to artificially recharge aquifers at rates greater than natural recharge.
inject fluids into the ground through water wells
During well pumpage, ________ of the head in the aquifer around the well occurs.
drawdown
During injection, there is a/an ________ in the head of the aquifer
increase
it is the change in hydraulic head observed at a well in an aquifer, typically due to pumping
drawdown
is the PH surface or groundwater dependent?
surface water dependent
drawdown typically happens from pumping because of?
aquifer test or well test
forms in the aquifer around a pumping well as the water level declines.
pumping cone/cone of depression
In ________ flow, the head is constant with time
steady state
in radial flow regime, what direction is the flow?
horizontal radial direction
This type of flow exists in the time period before the pressure transient has reached the boundaries of the reservoir (infinite-acting time period).
radial flow
this flow often observed following other flow regimes
radial flow
how many gallons in a cubic feet?
7.48 gals/cubic feet
another name for aquifer test
pumping test
how is an aquifer test done?
is conducted to evaluate an aquifer by:
- “stimulating” the aquifer through constant pumping, and
- observing the aquifer’s “response” (drawdown) in observation wells.
24-48h pump @ constant rate
if constant: sustainable
if volume changes: not sustainable
Aquifer testing is a common tool that hydrogeologists use to what?
characterize a system of:
- aquifers
- aquitards and
- flow system boundaries
why are pumping tests important?
to know if the groundwater of the particular area is sustainable
is a particular type of aquifer test where water is quickly added or removed from a groundwater well
slug test / bail-down test
how does a slug test happen?
- water is quickly added or removed from a groundwater well,
- the change in hydraulic head is monitored through time
- this is done in order to determine the near-well aquifer characteristics
hydrogeologic boundaries are considered to be either what?
recharge or barrier boundaries
is a region in which the aquifer is replenished
recharge boundary
edge of the aquifer where it terminates
barrier boundary
how does the edge of an aquifer terminate?
- thinning or abutting a low-permeability formation, or
- has been eroded away
