Gonzo goes with the flow
How do you know which direction water is traveling
high head to low head
What is a uniformity coefficient and how do you find it?
Cu = d60 / d10
found using a grain size distribution curve and used to determine how well sorted a soil is
For which method (Theis or Cooper-Jacob) do you need to check assumptions? Why?
Cooper Jacob, because it assumes a near-steady state.
What are the 3 equations you MUST have memorized for this course?
Q = -KiA
v = -(K/n)(dh/dx)
n = Vvoids / Vtotal
what is fluid dynamic viscosity
internal resistance to flow of a fluid at a given temperature
Define porosity, primary porosity, secondary porosity, and effective porosity
- porosity (quantified pore space)
- primary porosity (porosity caused by deposition)
- secondary porosity (porosity created after deposition)
- effective porosity (interconnected pore space)
When collecting slug test data for an unconfined aquifer, which test (rising or falling head) is more accurate? Why?
unconfined: rising head
What is the law of superposition in hydrogeology?
drawdown from any number of wells is equal to the sum of drawdown from all individual wells
What is the difference between confined and unconfined aquifers? What is a perched aquifer and what is an artesian aquifer?
Confined: head rises above bottom of confining unit
Perched: unconfined aquifer where water pools on top of a low-K lens like a cat on a shelf
Artesian: confined aquifer where water level rises above surface
when is it appropriate to use the word aquiclude
literally never unless you want to get sued
What are the names of the 2 muppets that heckle from the balcony?
HINT: they play Marley and Marley in A Christmas Carol
Waldorf & Statler
draw and compare the drawdown vs time curves for confined aquifers with
a. no leakage
b. leakage
(draw on board)
What are the Dupuit assumptions? Why do we care about them?
For an unconfined aquifer, the thickness of the aquifer is way larger than the change in head (true if little/no vertical flow).
This tells us if we can use confined aquifer equations on an unconfined aquifer.
Name 8 Muppets. Sesame street guys DO NOT count.
I'll know it when I hear it. I could probably name 15.
why are flow equations for unconfined and confined aquifers different
The thickness of confined aquifers are constant. The thickness for unconfined aquifers changes.
What are the 4 major aquifer classifications and how does flow occur through them?
1. Carbonate (dissolution channels)
2. Igneous and Metamorphic (fractures)
3. Course-grained Sedimentary (pores AND fractures)
4. Unconsolidated Sand and Gravel (pores)
Who do Gonzo and Rizzo play in a Muppet's Christmas Carol?
Gonzo: Charles Dickens
Rizzo the Rat: himself
List 5 assumptions needed for analysis of slug tests or pumping tests to be valid
1. aquifer is horizontal and horizontally infinite
2. aquifer is bounded on bottom by a confining layer
3. potentiometric surface is horizontal before pumping starts
4. changes in potentiometric surface are solely due to the test
5. all wells fully penetrate the aquifer of interest and are fully screened throughout the aquifer
When are 4 times it better to do a slug test compared to a pumping test?
Contaminated sites, sites with low budget/manpower, sites with low permeability, & situations that do not need high accuracy
name at least 4 different ways of finding hydraulic conductivity
1. using a grain size distribution curve
2. using empirical equations
3. using field instruments
4. using lab instruments
5. looking it up
where is vertical flow likely, and what does a vertical flow of 1.0 mean?
Likely near rivers, on slopes, near wells, after recharge, or when 2 aquifers join
A vertical flow of 1.0 is complete freefall, so you are almost certainly looking at a cavern or 2 separate aquifers.
Draw a drawdown vs time graph for pumping in an unconfined aquifer and explain each of the 3 sections
1. instantaneous release from storage (S=Ssb)
2. delayed yield
3. long term aquifer release (S=Sy)
Name 5 times you need to use the full groundwater flow equation instead of analytical solutions
1. heterogeneous & anisotropic aquifers
2. 3 dimensional aquifer flow
3. multiple pumping wells
4. boundary conditions
5. leaky aquitards
6. transient systems (sudden changes)
etc.
Explain the components of storativity in a confined aquifer.
- Compressibility of the soil matrix
- Compressibility or water
- aquifer thickness
If you were to watch A Muppets Christmas Carol today on a major streaming service, what major element of the movie would be missing and why?
The song "The Love is Gone" was taken out because "it is a bummer" and "doesn't appeal to young audiences"