NRES 251 - Water Exam I

The first exam for the water portion of NRES 251.

Define: Pools

Where water is found.

What are some examples of a pool?

Oceans, ice/glaciers, groundwater, soil water, permafrost, streams, lakes, rivers, wetlands, atmosphere.

Define: Flux

how we convert one pool to another (the ocean is a pool, the atmosphere is also a pool. Evaporation from the ocean is an example of this.)

What is an example of a flux?

Condensation, precipitation, infiltration/groundwater flow, overland flow, evaporation, transpiration, sublimation.

Define Interception:

refers to precipitation that is caught and held by plant surfaces (like leaves and stems). Some of this water evaporates back into the atmosphere before it ever reaches the ground.

What is the best approximation for how much drinking water we have on Earth?

0.01%

How much of Earth’s water is fresh?

2.5%

Define: Groundwater

Location in the soil profile where 100% of the pore space is filled with water.

Define: Water Table

Line demarcating the unsaturated and saturated zone.

Define: Aquifer

body of groundwater that can be extracted by a well. Some of them get named, but it’s usually only when there’s something bad happening to them.

Define: Flocculation

the process that follows coagulation, where gentle mixing helps the tiny particles (now neutralized by coagulants) come together to form larger, visible clumps.

Define: Coagulation

the process of adding chemicals to water to help remove suspended particles—like dirt, bacteria, and other impurities—that are too small to settle out or be filtered easily on their own.

Describe the process of flocculation or coagulation.

A positively charged floc will sorb with a negatively charged dissolved species and the heavier floc with settle out of solution.

Define: Water Withdrawal

Water that is removed from a waterbody for human use.

What is the largest water withdrawal in the US?

Thermoelectric.

Water withdrawals for thermoelectric primarily come from where?

Surface water.

Once-through cooling systems cooling systems negatively impact receiving water bodies in which way?

The warm water they release influences fish community and lower dissolved oxygen.

Why has irrigation from groundwater caused aquifers to be depleted?

Pumping rates are outpacing recharge.

Define: Contaminants of Emerging Concern (CEC)

little is known about exposure limits and regulations are being developed. 

Examples of CEC

• Pharmaceuticals and personal care products

• Veterinary hormones and antibiotics

• Endocrine disruptors

• Nanomaterials 

Describe Primary Treatments

First step in the process. Using settling to remove TSS and some BOD. Water shoots in really fast, forcing the bigger stuff out to the walls so it can quiet down.

Describe Secondary Treatments

Second step in the process. using air to stimulate decomposition by bubbling oxygen in, which removes BOD. The waste coming into pipes is very low in oxygen.

Describe Biological Nutrient Removal

Third step in the process. using staggered aerobic and anaerobic cells to stimulate phosphorus uptake by bacteria and nitrogen removal by bacteria (i.e. denitrification) They then trick the bacteria into gorging itself on the phosphorus due to stimulation.

Describe Secondary Clarification

using gravity to remove microorganisms (they can be reused) that were created during secondary treatment.

Describe the Final Treatment

almost exclusively using UV to shut down any remaining pathogens. Chlorine can also be used, but we don’t do that whole lot anymore. They don’t do that during winter though, since nobody is recreating in the water during winter.

What threats are oceans facing?

• Overharvesting

• Climate change

• Coastal eutrophication

Potential ET

ET rate for a generalized short green crop and water is NOT limiting. Highest ET you’d see off the landscape. Unfortunately, only about 60% accurate. Used in worst case scenarios.

Actual ET

the actual ET rate for a plant community, and a factor of plant physiology and climate/soil conditions. It’s very hard to calculate ET but is about 95% accurate. It is expensive and difficult to calculate. 

Thalweg

the point where there is the most stream discharge and, typically, where the stream is deepest.

Sublimation

Process that converts ice/snow directly into a vapor.

La Nina

large cold water observed in the equatorial Pacific Ocean from strong upwelling.

El Nino

warm water observed in the equatorial Pacific Ocean as upwelling is blocked. Upwelling and trade winds come to a standstill. Moisture gets dumped in the southeast during winter.

Anthropogenic Forcing Factors

Deforestation

• Can alter hydrologic cycles regionally and continentally. It will take a while for plants to grow back after being removed in mass, and with no plants to transpire water, the air will get very little moisture. Landscapes downwind will get no precipitation and will undergo droughts.  

Urbanization

• Infiltration rates are greatly reduced by removal of vegetation and impervious surfaces. 

• Groundwater is not replenished as quickly as it is being depleted, which results in a lower water table.

• Generates a lot of excess storm water.

Climate Change

• Making our precipitation incredibly erratic.

• Keeling curve – a way to measure CO₂. 

• Climate change has caused our oceans to heat up.

• Warmer air holds more moisture, so when it rains, it really rains. 

Define Watershed

• Catchment or drainage basin. A plot of land that drains water to a common point

• Mainly driven by topography. Water divides are much clearer and more definable in big mountains (big topography), but in Wisconsin you can’t see much.

Q = A x V

Stream discharge. A = area with water flow, V = velocity of water.

Floodplain

area adjacent to streams that are inundated during flood events (contained by levees). Between the natural levees and the bankfull.  

Bankfull

max depth of water in the stream channel just before it spills into the floodplain. You’ll only measure this from the lowest bank of the stream. There will be dead grass here. 

Sinuosity

degree of meander in a single thread stream.

• K = Stream Length (SL)/Valley length (VL)

Embeddedness

a measurement of what’s happening in your substrate. You would like to see that the substrate is nice, free, and clean between the particles because it is an awesome habitat for little bugs and fish eggs. High sediment isn’t good, though, because it basically becomes cement. 

Horton Overland Flow

Explains 95% of the overland runoff that we see on the landscape. It’s when precipitation exceeds infiltration rate.

Saturation-Excess Overland Flow

Precipitation raises the water table to the soil surface and runoff is generated. What normally happens is that it isn’t necessarily an intense rainfall event, but it might be a rainfall event that occurs over the course of a few days.

Q = C x i x A

Runoff. C = runoff coefficient, i = rainfall intensity, and A = drainage area.

Post Filtration Additives

we use chlorine to remove pathogens, fluoride to help build enamel on your teeth, and phosphorus for building up scale on the inside of city pipes. Chlorine needs to be at just the right amount to kill pathogens and not hurt people. Fluoride can really only help kids grow their teeth. Scale in city pipes helps keep the lead from old lead pipes out of your drinking water. Water towers, due to gravity, naturally apply the perfect amount of pressure to pipes. However, phosphorus is pretty notorious for being good for algal blooms.

Biological Oxygen Demand (BOD)

measures oxygen consumption by decomposition of organic matter over a 5 or 7 day (we would then call it a BOD 5 or BOD 7) period at twenty-five degrees Celsius. ~60% of organic matter is broken down.

Chemical Oxygen Demand (COD)

measures the amount of oxygen that is consumed by a strong chemical oxidant (titration). Instead of letting bacteria break down the organic matter, we add a chemical compound that is incredibly effective. ~95% of the organic matter is broken down. You can get results near instantly.