Watershed final

The primary water use in the western united states is for electric power generation

false

latent heat is required to sublimate snow

true

conductive energy transfers are relatively minor on a watershed level. why?

plant tissues and soil are poor conductors of heat and conduction is a slow process that requires direct contact

vegetation type and structure are most indicative of

long term cycles in rainfall

what was the cause of the hypoxic zone in the gulf of mexico

nutrients coming down the mississippi river

which of the following are viable means for dealing with problems of water supply (quantity)

reduction in evapotranspiration losses and importation from another location

active surface is important for management because

this is hwere energy exchanges occur on the watershed

precipitation falls as snow because

it falls through cold air

what is the difference between retention storage and detention storage

retention storage includes capillary pores or micropores. water in these storage capacities are held against the pull of gravity.

detention storage has noncapillary pores. it contains water that will be moved by gravity

which results in higher rates of infiltration

rain (as opposed to snow)

what is the mathematical difference between gross precipitation and net precipitation

net precipitation= gross precipitation - interception

when a soil is saturated only 90% of the pore space is filled

false

water held against the pull of gravity is called

field capacity

organic matter in the soil adds nutrients but it doesn’t increase available water content

false

which of the following is another name for detention storage

non capillary storage

infiltration capacity is the maximum rate at which a soil can absorb water

true

vegetative cover can offer some protection to the soil. which of these offers the least protection

field crops

other options: native grassland, pasture, native forest

which of the following results in a high infiltration capacity

loose structure, high organic matter, coarse texture (all of the above)

Both the Rational Method and the SCS Curve Number Method show that even a small development can result in increased potential runoff volumes. Describe one (1) consequence if we fail to plan for that increase in runoff.

A more "obvious" consequence of failure to plan for increased runoff is flooding. Urbanization replaces natural landsscapes with concrete, and rainwater has nowhere to infiltrate, so instead it runs off into waterways and an increased rate. Increased volume and velocity can overwhelm drainage systems and cause flooding. 

A 100 year storm is expected to only occur once in 100 years

false

List all 3 factors that increase a soil’s susceptibility to erosion

steep slope, lack of soil aggregates, lack of organic matter

(also listed: high humidity, short slope)

Which of the following are gaps in our knowledge regarding water quality issues?

Synergistic effects between different chemical compounds

Cause-and-effect between exposure and symptoms

Long-term effects of various chemical compounds

Rates of biomagnification

(all are correct)

Which is not true about the variable source area as it relates to runoff?

all areas must contribute flows

water quality standards are based on

specific use

how does biological oxygen demand impact dissolved oxygen levels

greater BOD results in lower DO

Which of the following should be considered before implementing an Active Measure on the watershed?

cost, materials available for use, legal constraints, limitations of the techniques (all of the above)

What is the purpose of the spillway for an earth dam?

prevent water flows over the dam

how much maintenance is needed for rock check dams

little; if properly built

Which of the following is NOT a consideration when planning to re-vegetate a riparian zone?

earthworm abundance

Which of the following techniques can be most improved with the use of fencing?

riparian plantings

Wildlife tunnels and crossings rely on the following for success:

fences to guide the animals

Why are fish screens important?

keep fish out of electricity generating turbines; control the spread of invasive fish

Which of the following is not a use for a snow fence?

increase snow melt rate

What is a Feasibility Study and in what step in developing a watershed management plan would you conduct it?

A feasability study is what is conducted to determine if a project is likely to succeed and is practical. Feasability studies are conducted once goals for the watershed are already set, but before any management actions have been taken. 

A watershed with a basin circularity ratio (C = Ab / Ac) closer to 1, will be less compact, and therefore more vulnerable to the direction of a storm.

false

Both latent heat and sensible heat are required to sublimate snow.

true

Hydrologic Unit Codes (HUC) are useful for watershed designations because they are not constrained by political boundaries.

true

In both theories of precipitation development, condensation nuclei are required to form droplets.

true

Increasing water yield for human use is the most important aspect of watershed management.

false

Land surfaces with a low albedo absorb more heat energy than land surfaces with a high albedo.

true

Long-term cycles of rainfall are reflected in changes in vegetation type and structure.

true

Reducing evapotranspiration loss is accomplished by increasing the energy available for the vaporization of water.

false

The greater the temperature difference between the evaporating surface and the atmosphere, the lower the rate of convective heat transfer.

false

The rain shadow effect, where one side of a mountain range receives little rainfall while the other side receives most of the rainfall, results from orographic storms.

true

The rate of convective heat transfer is directly proportional to air speed, temperature, and vapor pressure gradients between the surface and the atmosphere, as well as the surface area. Therefore, one would expect an increase in surface roughness to decrease the rate of convective heat transport.

false

When delineating watersheds with a GIS, “pour points” are those where water is added to a watershed and have no relation to where water leaves the watershed.

false

“Fossil water” is the name for an aquifer that is not being recharged.

true

Choose all the following that are Fixed Characteristics of the Active Surface.

slope, size, elevatio, aspect

Which of the following drainage basin characteristics are more likely to be associated with a basin with a High Drainage Density. Choose all the correct answers.

contain short, steep slopes; has more channelized differences; responds quicker to a storm event

Which of the following drainage basin characteristics are more likely to be associated with a basin with a Low Drainage Density. Choose all the correct answers.

drains slower; less susceptible to flash flooding

Which of the following are true about Stream Order designations?

Main channel is determined ahead of time with Horton System

 

Small tributaries have a stream order value of 1

 

Strahler System is less ambiguous than Horton System

 

(All of the above)= correct

Which of the following is most important to remember when measuring snowfall?

placement away from drifts

Which storm type is most likely to produce the rain shadow effect?

orographic

Briefly explain why drought in California is an issue that all Americans should be concerned about.

California is a major food producer, and produces over 1/3 of fruits and vegetables in the US. Drought can reduce crop yields and increase food prices, which in turn can lead to economical disadvantages through job losses and higher costs. 

How does Throughfall differ from Stemflow?

Throughfall is water that continues downward, through leaves and branches, and reaches the soil surface. 

 

Stemflow is water that flows directly down stems and a tree's trunk. It then reaches the soil surface that way. 

What are the four primary objectives of Watershed Management?

1. Maintain/increase water yield

2. Maintain/increase water quality

3. Regulate timing of stream flow

4. Control excessive soil erosion/runoff

What are the three major Water Resource Problems? Provide one viable solution for each, as we discussed in class.

1. Absolute supply problems; solution can be importation of water from an area where there is a naturally occuring surplus

2. Problems of regimen; solution= increasing channel capaticy to handle excess volume of flows

3. Problems of quality; no simple solution exists. If naturally unsafe for use, the options are finding a different source of water, or treating the water to make it safe. If unsuitable due to humans, options include treatment of wastes prior to discharging into streams or modifying waste disposal. 

What is the difference between gross precipitation and net precipitation? Why is this difference important for management?

Gross precipitation is the amount of total precipitation falling from the atmopshere, and can be measured above the canopy

Net precipitation is the amount of water that reaches the surface through the canopy. 

difference is interceptiom, which can be managed by manipulating vegetation

Briefly describe how Interception is impacted by the following:  wind, vegetation

Vegetation can impact interception through variations in vegetation density, as well as the type of vegetation. Vegetation with rough bark or hairy leaves will contain more water than those with opposite traits. Dense vegetation makes it more difficult for water to reach the soil surface, meaning the interception rate increases as density of vegetation increases.

A headcut is the actively cutting downstream extension of a gully.

false

Permeable concrete is not currently suitable for use on high-volume roads.

true

Regarding runoff, an urban area functions like a watershed with a high Drainage Density.

true

Field capacity refers to the maximum amount of water that a given soil can retain against the force of gravity.

true

With the “variable source area” concept of runoff, different areas of the watershed contribute runoff flows at different times of the event, but all areas must contribute flows.

false

When a toxin passes from one trophic level to the next, the concentration increases in a process called biomagnification.

true

Endocrine-disrupting chemicals mimic natural hormones and cause problems by interfering with hormone messaging systems.

true

Heavy metals occur naturally, but human activities concentrate them to levels that can be toxic.

true

The peak flow on the hydrograph represents the point at which the whole watershed is contributing to a runoff event.

false

E. coli is the biological indicator of drinking water use for humans.

true

Phosphorus is less of a problem for water quality than Nitrate because it is more mobile in the environment.

false

Unlike all the processes we’ve discussed, Water Quality is unique in that management can impact it, and at the same time it can influence management.

true

Water evaporates from the soil primarily from the surface. Which of the following processes brings water upward to the soil surface prior to evaporating?

capillarity

Which of the following does NOT result in increased rates of evaporation?

higher humidity

A green roof is not applicable in all urban settings. Which of the following are limitations in the application of a green roof?

cost, weight

You have a dream of solving our problem of dust clouds in Lubbock (dust from cotton fields outside of town). Describe three techniques (FROM CLASS!) that you could use to realize your dream.

Increased vegetation cover, furrow diking, and supplementing more clay-type soils can help decrease dust clouds in Lubbock 

Which step in the erosion process requires the most energy?

dislodgement

If you planned for a 50-year storm event, what is one consequence of experiencing a 100-year event? What is the probability of experiencing a 100-year event in any given year?

One consequence would be sever flooding, if only a 50-year storm event was planned for. The probability for experiencing a 100-year storm event is 1 %

It is easier to erode sand than clay, even though sand particles are larger than clay particles, because:

clay particles form aggregates, which are more difficult to dislodge and transport

Describe one route by which pharmaceuticals and other endocrine-disrupting chemicals enter the environment.

Runoff can be a route as to how pharmaceuticals and other chemicals enter the environment.

How does “Specific Use” define levels of water quality?

Specific use is how the use of the body of water itself determines what the appropriate water quality standards are. For example, irrigation water and drinking water may have different quality standards because they have different uses. 

Describe what would happen if you added sand to a heavy clay soil, using the following descriptors: 

                        Increase      Stay the same      Decrease

Infiltration rate

Field capacity

Available water

Wilting point

Capillary storage

The following would occur if sand was added to a heavy clay soil-

Infiltration rate: increase

Field capacity: decrease

Available water: decrease

Wilting point: decrease

Capillary storage: decrease

You've been hired in New Mexico to manage a large tract of land. One of the issues you face is excessive erosion, and a quick survey of the property reveals a number of large gullies. Name three (3) techniques you could propose to address erosion in them. ONLY include techniques from class!

Gullies often arise due to excessive water erosion. Three techniques to reduce the impact of water erosion and to reduce or eliminate the detachment of soil include adding more vegetative cover, increasing soil structure with organic matter, and reducing runoff by not straightening channels and using furrow diking on agricultural land. 

Reshaping the slopes of the gullies may reduce velocity of runoff and water erosion, and increase infiltration. Using fast growing, native grasses to increase vegetation cover is a quick and introductory level of management to help lessen the impact of water erosion on that land. Cover crops can also be planted while the native grasses are becoming established. Replacing and repairing erosion controls on the land after heavy storms would be recommended for long-term maintenance and monitoring.