NRES 251 Exam 4 - UWSP

How do we measure groundwater elevation in the field?

You can determine the ground water level/elevation by subtracting the depth to water from the surface level.

Determine which direction groundwater flows

Always flows from a high hydraulic head to a low hydraulic head.

Recharge: Surface water flows into groundwater
Discharge: Groundwater flows into surface water

Capillary Fringe

Area just above the water table where soil is partially saturated

Water Table

Point where saturated zone and non saturated zone meet

Artificial Recharge

Specific areas designated to recharge groundwater

- Made up of a recharge basin in order to saturate a depleting aquifer.

Understand and be able to use Darcy's Law based on real life data

- Medium (Sand or Clay) that water flows through determines flow rate
- Diameter/cross sectional area determines flow rate
- Hydraulic head at each end of each pipe determines flow

Calculate Hydraulic Gradient

H1 - H2/Distance Between

Darcys Law Equation

Q = s K A

s = hydraulic gradient
K = hydraulic conductivity
A = cross sectional area (ft squared)
n = pore space

Velocity : Q/A = s * K
Seepage : Vsub s : (s * K)/n

Hydraulic Head

Water table elevation relative to sea level

Potentiometric

Level that ground water needs to be for a well
Unconfined Aquifer: Water Table
Confined: Over ground level (Needs pressure to flow in artesian well)

Understand the structure of H2O and why this structure results in unique properties

2 Hydrogen and 1 Oxygen Covalently Bonded
Partially positive and partially negative charged

Special Capabilities Of Water

- Only substance that can be a liquid, gas, and a solid
- Has slightly positive and negative charge so it bonds to other water molecules as well as surfaces (adhesion/cohesion)
- One of highest specific heat capacities of any substance (requires lots of energy)
- Good at dissolving polar substances like salt
- Capillary action (moves up in plants/defies gravity)
- Holds more Dissolved Oxygen when cold

Physical Water Quality Measures

Temp
- Can increase of decrease biological activity in the water
- Effects amounts of DO in the water
- Major temp changes can cause fish mortality (3-5 degrees)
Turbidity
- How well light can penetrate the water
- High turbidity means low quality
- Influenced by erosion or algae

Chemical Water Quality Measures

Heavy metals: Cancer causing
Nutrients: Too much means algae which can eat up all of the DO for fish
Chloride: From road salts or septic tanks
Specific conductance: Higher specific conductance can indicate pollutants (freshwater should be 150-200 micro siemens)
Organic pollutants: pesticides and herbicides

Eutrophication

increase in organic matter (typically N or P) that results in DO depletion

How Eutrophication works

1. Excess nutrients are carried into water
2. They help stimulate algae growth with sunlight
3. Algae die and float to bottom
4. Microbes colonize on the dead algae
5. Microbes decompose algae and eat up all of the dissolved oxygen

Concerns of Eutrophication

- Can kill off fish due to decreased DO
- Can release toxins into the water and air
- Loss of revenue from tourism and home ownership

Nitrogen Compounds

- Nitrate: Highly mobile, leaches into the ground water
- Nitrite: Unstable form of nitrogen, indicates reactions are taking place
- Ammonium/Ammonia: Ionized form of nitrogen, common with manure application (Ammonia is toxic to biotic life)

Describe stream formation of compartments/habitats

- Oxbows
- Alluvial Deposition
- Meander Scars
Inside bends: Deposition
Outside Bends: Erosion

Riffle

pollution intolerant, low predation (High DO)

Run

Run - predators

Pool

Pool - pollution tolerant, larger organisms (Low DO)

Floodplains

Remove nutrients, sediment deposition

Oligotrophic lakes

low nutrients, productivity is low, high clarity

Mesotrophic lakes

moderate nutrients, productivity, and clarity

Eutrophic lakes

high nutrients and productivity, low clarity

Deep lakes

large volume, more diluted, smaller littoral zone (grassy area), startification

Shallow Lakes

small volume, high nutrients, very productive, constant mixing

Epimilion

top layer of lake, high temp, low density

Metalimnion

middle layer of lake, rapid temp change, prevents mixing (in winter it is closer to the surface)

Hypolimnion

bottom layer of lake, low temp, high density

Aerators

Disrupt ice formation and help provide DO for fish

Wetland definition

Saturated soils and/or standing water exists long enough during the growing season to develop hydric soils and a plant community dominated by hydro phytic vegetation

Hydrophytic Vegetation

Plants that evolved to grow in low oxygen environments

Hydric soils

Soil developed under low oxygen conditions

Purposes of wetland

- Ground water recharge
- Flood mitigation
- Carbon storage in soils (slow decomposition)
- Favor denitrification (removal of N)
- Nutrient removal

Management of wetlands

Managed for waterfowl, and restoration projects are ongoing to increase the number of wetlands