When water is pumped from a well a depression is often produced in the water table such a depression is called?
quiz 11 geol
| Question | Answer |
|---|---|
| ________ would have the largest capacity to naturally remove sewage pollutants | slightly clayey sand |
| When water is pumped from a well, a depression is often produced in the water table. Such a depression is a(n) _______ | cone of depression |
What happens to the water table when water is pumped from a well?
Pumping from a well in a water table aquifer lowers the water table near the well. This area is known as a cone of depression. The land area above a cone of depression is call the area of influence.
When water is pumped from a well drawdown occurs Which of the following is a true statement regarding drawdown?
When water is pumped from a well, drawdown occurs. Which of the following is a true statement regarding drawdown? Drawdown decreases with increasing distance from the well.
What is the cone of depression in wells?
Cone of depression: A depression in the groundwater table or potentiometric surface that has the shape of an inverted cone and develops around a well from which water is being withdrawn. The slopes of the cone become increasingly steep the closer they are to the well.
What causes cone of depression?
A Cone of Depression is formed where the water table sinks at an exact point because of heavy pumping. Water is extracted out of the ground which leaves an airy space around the soil particles.
What is a drawdown in water?
Drawdown is a term applied to the maximum lowering of the groundwater table caused by pumping or artesian flow (Figure D60). It is measured as the difference between the initial level of water in a well before pumping, and the static, or stabilized, level of water after a long period of pumping.
What happens when the cone of depression created by pumping of wells extends to the nearby wells?
Pumping a well lowers the water level around the well to form a cone of depression in the water table. If the cone of depression extends to other nearby wells, the water level in those wells will be lowered.
What causes a cone of depression?
The 'zone of saturation' occurs where the pores in the aquifer area are filled with water completely and is just beneath the water table. Aquifers are underground water bodies from which groundwater can be pumped out using a water well. This leads to the formation of a 'cone of depression'.
What happens when water is pumped from a well quizlet?
When water is pumped form a well, the water table is typically drawn down around the well into a depression shaped like an inverted cone known as a cone of depression. In turn, this lowers the water table around the region of the well.
How is a cone of depression formed?
A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer (water table), this is an actual depression of the water levels. In confined aquifers (artesian), the cone of depression is a reduction in the pressure head surrounding the pumped well.
What causes a depression on the water table?
As the water flows into the well, the water levels or pressure in the aquifer around the well decrease. The amount of this decline becomes less with distance from the well, resulting in a cone-shaped depression radiating away from the well.
Why is a cone of depression significant?
Because water flows down to lower points, the cone of depression could change the direction groundwater flows in. That might change what you find IN your well water; if there's a source of pollution near your well, the cone of depression might affect whether the pollution flows toward or away from the well.
How fast does well water replenish?
Well water can replenish at a rate of 5 gallons per minute on average, but it will vary. It depends on the age of your well, how long you've been using it, the well's location or geology, and the aquifer the well taps into to replenish its water level.
What is the draw down at the pumping well?
Drawdown is a term applied to the maximum lowering of the groundwater table caused by pumping or artesian flow (Figure D60). It is measured as the difference between the initial level of water in a well before pumping, and the static, or stabilized, level of water after a long period of pumping.
What is a good drawdown for a well?
As a first approximation, 30' has been used as an effective limit to high-rate irrigation pumping (the actual limiting thickness will vary with local conditions). For an irrigated area, this is effective depletion.
When water is withdrawn from a well a cone of depression is created in which?
A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer (water table), this is an actual depression of the water levels.
What is the cone of depression quizlet?
What is the cone of depression? the shape that the water table takes on near a pumping well.
When a cone of depression forms around a pumping well does it increase or decrease the gradient of the water table in the area around the well?
When a well is pumped, the water level in the well is lowered. By lowering this water level, a gradient occurs between the water in the surrounding aquifer and the water in the well. Because water flows from high to low water levels or pressure, this gradient produces a flow from the surrounding aquifer into the well.
Can you run out of water with a well?
Can Your Well Run Out of Water? If your well has been correctly drilled, it can last your family a lifetime, but it is possible for a well to run dry. This often happens with wells that are too shallow. If a well is not drilled deep enough, it may only be a water table well.
Does rain replenish well water?
While your well is a 6” hole in the ground, it is not directly replenished by rainfall, as you might expect a cistern to function. The rainfall that seeps into the ground on your property moves through the soil at a rate of only 10 feet per year.
Why is well drawdown important?
Drawdown data can be combined with the yield from the well to evaluate the efficiency and performance of a well or pumping unit. One of the most important reasons for measuring drawdown is to make sure that the source water is adequate and not being depleted.
What is considered good gallons per minute for a well?
That said, a typical minimum acceptable well yield is 3 gallons per minute; some lenders want to see 5 gpm; And some authorities will accept lower well yields, down to 2 gpm provided that 1,500 gallons or a similar quantity of on-site water storage is also provided.
When a well is heavily pumped?
When a well is over pumped, water is withdrawn faster than it is coming in and the water level in the well drops dramatically as the geology around the well drains. The longer this goes on the more widespread the dewatered area is.
What causes a cone of depression in the water table?
A cone of depression occurs in an aquifer when groundwater is pumped from a well. In an unconfined aquifer (water table), this is an actual depression of the water levels. In confined aquifers (artesian), the cone of depression is a reduction in the pressure head surrounding the pumped well.
What might cause a cone of depression to become larger or smaller?
The cone of depression changes size If there is no precipitation to recharge the aquifer, and the well keeps pumping, the pump will pull water from a greater distance, and the cone of depression will get deeper and wider. After heavy precipitation, with good recharge, it will get smaller.
How long does a well take to refill?
Well water can replenish at a rate of 5 gallons per minute on average, but it will vary. It depends on the age of your well, how long you've been using it, the well's location or geology, and the aquifer the well taps into to replenish its water level.
Does rain fill your well?
While your well is a 6” hole in the ground, it is not directly replenished by rainfall, as you might expect a cistern to function. The rainfall that seeps into the ground on your property moves through the soil at a rate of only 10 feet per year.
How long does a well take to fill back up?
Well water can replenish at a rate of 5 gallons per minute on average, but it will vary. It depends on the age of your well, how long you've been using it, the well's location or geology, and the aquifer the well taps into to replenish its water level.
Can you run out of well water?
Well water will run out if the groundwater level drops below the water intake depth. This can be caused by natural or man-made variations in groundwater height including reduced precipitation, slow groundwater recharge, well infill, high water usage, well drawdown or hydrofracking.
Do wells run out of water?
Well water will run out if the groundwater level drops below the water intake depth. This can be caused by natural or man-made variations in groundwater height including reduced precipitation, slow groundwater recharge, well infill, high water usage, well drawdown or hydrofracking.