Questions tagged [groundwater]
The groundwater tag has no usage guidance.
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Would the subsurface event leading to tree death at West Tern Lake in Yellowstone be visible in thermal imaging?
The New York Times article It’s Warm and Stealthy, and It Killed Yellowstone Trees and Turned Soil Pale describes an even that took place over the past few decades where a small and well-defined ...
0
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1answer
44 views
What effect does concretization (paving/flooring with concrete) has on ground water table
I am a newbie for hydrology. If the question seems to have "well known answer", I appreciate if you point me to the resources. I will add details to the question based on comments.
Consider a town of ...
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0answers
20 views
The DRASTIC groundwater vulnerability model and it's relevance today
I am reading a groundwater pollution vulnerability study by Mark Angle of the Ohio Dpet. of Natural Resources (ODNR) for my county. The model used to assess the groundwater vulnerability for the ...
14
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3answers
3k views
How is it possible to use up the water in a region?
The Dead Sea, rivers in California and the Aral Sea are said to be shrinking due to water usage, e.g. for agriculture. Yet the water must go somewhere.
After the fields are irrigated, the water ...
1
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1answer
75 views
What is the cause of temporary smell and black color of underground water?
We have a well (about 1200KM away from sea and 60 meter deep), the water when taken out has slightly dark color and has smell. But strangely in about 12 hours the smell and black color vanishes and ...
1
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1answer
183 views
Why do we consider hydrostatic pressure and lithostatic pressure separately?
In petroleum geology, why do we consider hydrostatic pressure and lithostatic pressure separately?
Surely the pressure at any point, whether fluid or rock, at depth is simply equal the weight of all ...
2
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1answer
57 views
Does the configuration of a confined layer change the storage?
I have a confined aquifer of sand. I will temporarily drain the aquifer, remove the top one meter of the aquifer and then replace that with a layer of gravel. After that I will restore the layer (and ...
5
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3answers
80 views
Transferring water using underground channel
I heard in tv show, there are water channels in underground like rivers or small channels! So I just wondered why don't we use such underground water channels to recharge the underground water of one ...
2
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2answers
113 views
Searching for ground water
I would like to attempt to build a well-type structure in a woodland area. This woodland is mainly inhabited with Silver Birch and Sycamores and there is a shallow stream running down off of a ...
2
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1answer
90 views
Hydrology - Flowrate vs. radius of influence
I am using the following equation (Theim/Dupuit) to determine radius of influence for an unconfined aquifer.
Assume all other variables are held constant. If Q increases, does the Radius of ...
4
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2answers
51 views
Does nitrate take a particular long time to percolate from surface into groundwater?
In a recent discussion with a farmer, the (at least in northwestern Germany) "popular" topic of nitrate infiltration into groundwater came up. The general view is that lots of fields receive more ...
1
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1answer
325 views
Concept of artesian aquifers and pressure is not clear.
I do not understand how the Artesian aquifer is causing the water in the flowing well to reach a level higher than the ground surface? And what role does the piezometric surface play in it?
3
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1answer
39 views
What controls how quickly groundwater gets recharged from rainfall?
This is a follow up question to an earlier question I asked about how groundwater gets mapped. I have read that our groundwater is getting exhausted as people drill to deeper depths and lift ...
7
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2answers
130 views
How is ground water mapped?
This is probably a very easy question to answer but how are the USGS maps showing ground water locations mapped? Is it a guy going around taking core samples? Or is it done using satellites and ...
1
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1answer
252 views
Can a microGPS tracker trace the path of an underwater drainage conduit?
The Devil's Kettle is a pothole in the rock where a small river disappears underground in the Judge C.R. Magney State Park in Minnesota. Would it be possible to trace the path of the drainage conduit ...
3
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0answers
55 views
Best material for Piezometer tube in water well
I have a 150M deep borehole. We want to measure ground water level using a pressure sensor.
I believe that it is best practice to make use of a Piezometer tube ...
2
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0answers
66 views
Approaches for estimating potential evapotranspiration for non agricultural landuse classes
We are studying the water balance of a small catchment close to Jaipur, Rajasthan India in a semiarid climate. About a quarter of the landuse within the catchment is agriculture, the rest is divided ...
6
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0answers
63 views
Chloride and evaporation
I have a layered aquifer with water that contains high concentrations of calcium and sulfate (~400 mg/L Ca2+, ~1300 mg/L SO42-), at 50 cm below ground surface (bgs), 250 cm bgs and 300 cm bgs. The ...
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0answers
43 views
Pyrite oxidation
How much pyrite has to be oxidized to produce a sulfate concentration of 15 mM?
If the solution initially has a pH of 8, roughly what would the pH drop to if there is no buffering of acidity?
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0answers
18 views
What models are available to estimate effect of surface water on groundwater quality?
I want to determine the effect of surface water quality or the effect of chemicals used on surface like fertilizers on groundwater. What choices do I have for predicting groundwater quality? What are ...
4
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0answers
99 views
Dolomite and calcite precipitation
In an engineered wetland, there is groundwater flow from an aquifer with a chemical composition that is rich in magnesium, calcium and sulfate. We are finding that the aquifer is consistently ...
1
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2answers
73 views
Limitations on mineral precipitation from solution
If the solubility constant for a mineral is exceeded and, thermodynamically, a mineral is favored to precipitate in solution, are there any factors that may limit this from happening? Perhaps kinetics?...
2
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1answer
365 views
Gypsum saturation index
I did some geochemical modelling and found groundwater samples I have are saturated with respect to the mineral gypsum. I need some help with interpretation, more information is given below.
The ...
2
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2answers
115 views
Where on Earth does paleo-groundwater exist?
Where on Earth do we expect to find very old groundwater (infiltrated thousands of years ago)?
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0answers
42 views
Modelling the unsaturated zone in FeFlow in seawater intrusion scenarios
Does anyone have experience with modelling seawater intrusion scenarios in Feflow?
In my models, my mass-concentration seems to drive up into the unsaturated vadose zone, which I don't believe is ...
3
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0answers
1k views
Radius of Influence - groundwater pump well
What is the best method for calculating radius of influence for a pump well in an unconfined aquifer?
I know the aquifer transmissivity (T), storativity (S), pump rate (Q), aquifer thickness (b), ...
1
vote
1answer
320 views
Hydrology - Depression cone VS transmissivity
My question concerns the depression cone of a pumping well in a confined aquifer: Say the transmissivity of the aquifer is 1200 m^2/day how will the cone change if the transmissivity is 600 m^2/day? ...
4
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3answers
762 views
What is meant by inverted water table?
There are some papers in literature which discuss stream-aquifer interaction. They describe that the stream aquifer interaction ranges from connection to disconnection. When there is disconnection, ...
4
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1answer
55 views
What forms do groundwater flow equations have when Dupuit supposition is not considered?
Near pumping wells or near/beneath a stream, the groundwater flow is not totally horizontal and the vertical component of groundwater movement at these points cannot be ignored in reality. Often, ...
5
votes
1answer
135 views
Coupling recharge with 1D groundwater flow model
Suppose we are modeling 1D groundwater flow in an aquifer of extent $x$ from $A(x=0)$ to $C$. Lets say for unsteady state conditions, the input is at $A(x=0)$, we can model piezometeric response at $B ...
5
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0answers
193 views
What is the difference between the Hydraulic diffusion equation and the Richards equation in groundwater dynamics?
What is the difference between the Hydraulic diffusion equation and the Richards equation in groundwater dynamics? I want also to understand the difference between the different storage coefficients (...
2
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1answer
1k views
How come ZamZam water in Mecca never runs out?
It is located in the middle of a dry desert in Mecca and the astonishing thing is all wells around Mecca dried out except this one!
So how can a small well, with a diameter of about 1.46 meter to 2....
3
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0answers
305 views
Linear Boussinesq Equation for groundwater flow in inconfined aquifer?
I was reading a paper (equation 1 in linked paper) where they used 'linearized Boussinesq' equation to model groundwater in unconfined aquifer. The linearized Boussinesq equation described in the ...
8
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2answers
811 views
How old is Earth's groundwater?
In my house, we drink the groundwater that we get from our well. It is 40 meters deep. The question is, how old is the water that we drink today? Is it from the rain 100 years ago?
Another issue is, ...
3
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1answer
87 views
Has anyone driven under, or received camera footage from, the Great Artesian Basin in Australia?
I can find information about the basin as a water-source, along with photos of the ground over its 1,700,000 square km surface. But have divers ever entered this space, or tunnels been dug for cameras,...
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6answers
5k views
How can we have groundwater depletion when the Earth is 78% covered with oceans?
Why does depletion of underground water levels happening, if the Earth is covered by nearly 78% water, and there is also water in rivers and lakes?
How can we still lack groundwater?
4
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0answers
81 views
Does perchlorate(rocket fuel) and jet fuel make the salt and ground water near Cape Canaveral dangerous?
I've gotten into paddle surfing and I'm looking for a place to live and surf.
I've been looking at an buying a condo in Cocoa Beach because of it’s proximity to Orlando and Cocoa’s decent but ...
6
votes
1answer
105 views
Do Hydro-Carbon extraction units pollute ground water?
I am from India, Tamilnadu state. Our nation has planned to have hydrocarbon extraction units in our Thanjavur villages. We, a 70 million people Tamilnadu state get most of our rice from that region.
...
5
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2answers
151 views
Can ocean temperatures affect groundwater storage capacity ?
In a paper published in Nature Geoscience (paper) the authors conclude :
Declining precipitation in northern India is linked to Indian Ocean
warming, suggesting a previously unrecognized ...
4
votes
1answer
613 views
Why does an artesian well dry slower than a normal well?
In the diagram below, well A is an artesian well and well B is a normal well.
Well B's pipe is lower than the water table. By looking at the picture, I decide that well A would try quicker than well B,...
4
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3answers
636 views
How do you determine the age of >60 year old water?
I have been looking around at this topic recently, and it seems that it is relatively easy to determine the age of young water, by testing the concentration of anthropogenic contaminants. However, I'...
5
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1answer
846 views
Why confined aquifers have low storage?
Identical drop in head in unconfined and confined aquifers releases different amounts of water. The confined aquifer releases less water and thus has less specific storage. When both aquifers are ...
6
votes
2answers
8k views
How much time does water takes to reach to the ground?
I want to understand the phenomena where water droplets after precipitation reaches to the ground.
How much time does it take to become ground water or in other words how much time is taken by water ...
4
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1answer
343 views
Why is fluid pressure in a fractured rock reservoir only dependent on hydrostatic pressure?
Why does lithostatic pressure not play a role? (or does it?)
2
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0answers
258 views
What is difference between Riverbed conductance term and streambed leakance/retardation coefficient?
In literature some times to account for semi-pervious sediments at bottom of stream, streambed leakance also called retardation coefficient ($L$) is used. This is equal to the ratio of conductivity of ...
3
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0answers
60 views
How to integrate dry wells into groundwater level mapping automatically (inequality constraints on the interpolation)?
I'm interested in automating spatial interpolation of groundwater level measurements. I'm wondering if anyone knows a method for automatically taking into account things like dry wells, where I can't ...
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0answers
92 views
Groundwater “GMS-MODFLOW” Transient Model
I have transient model with domain 200*200m and consists of 5 layers with 45 stress period, first layer is alluvium and the other 4 layers are weathered rock will be solved using traditional MODFLOW ...
3
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1answer
207 views
How are biological oxygen demand and depth related?
What is the relation between biological oxygen demand (BOD) and depth? I need to calculate the BOD of a drinking water tank and I have ultimate BOD at the surface of water, but I need to calculate it ...
6
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1answer
247 views
What would happen if the same soil received waste water contaminants for a long time?
I know that soil is used to filter septic systems within our treatment system, however what happens to this soil that is used in filtration, I know it would be changed every once in a while but what ...
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1answer
415 views
Is it possible that the recent droughts are signs of epic crust failure? [closed]
The full question is: Is it possible that the recent, successive, long droughts from Australia to the West Coast of both American continents are signs of epic crust failure?
The question is aimed ...
