UT Austin Invitational — Dynamic Planet

Dynamic Planet · Division B · UT Austin Invitational · 2022

53 questions · 61 points · 50 min· 24 questions from the original omitted

Original test source

Do NOT open the packet until directed to do so by the tournament proctor(s).

Each team may bring a 2” or smaller three-ring binder and two stand-alone calculators of any type.
You will have 50 minutes to complete this test.
Some questions have “select ALL that apply.” In Section 1, the point value (not given) for these questions is equal to the number of correct answers. In Section 2, the given point value is NOT necessarily equal to the number of correct answers. One or more answers may apply.
For these questions, correct answers earn 1 pt, incorrectly marked answers deduct 1 pt, and unmarked correct answers do not earn nor deduct points.
The minimum score per multiple-select question is zero.
Please write the letter(s) of the answer(s) to each multiple-choice or multiple-select question IN CAPITAL LETTERS. No credit will be given for illegible or unclear answers.
Tiebreakers are marked in the test in the order they will be broken (e.g., “TB1” is the first tiebreaker, “TB2” the second, etc.). Questions 60, 52, 28, 5, 16, 17, 34, 42, 67, 66

Section 1

Reminder: Some questions with multiple correct answers are worth more than 1 pt each.

Question 1

1 pt

Near the headwaters of a stream in steep terrain, the size and shape of the sediment is most likely

A. relatively small and angularB. relatively small and roundC. relatively large and angularD. relatively large and round

Question 2

1 pt

According to the Strahler stream order system, the merging of two third-order streams results in a stream that is of what order?

Question 3

1 pt

If a region becomes afforested (has more vegetation), which choice best describes the changes to local runoff and transpiration?

A. Runoff: Increase; Transpiration: IncreaseB. Runoff: Increase; Transpiration: No changeC. Runoff: Increase; Transpiration: DecreaseD. Runoff: Decrease; Transpiration: IncreaseE. Runoff: Decrease; Transpiration: No changeF. Runoff: Decrease; Transpiration: Decrease

Question 4

1 pt

A river that can carry and ____ large particles, by definition, has a relatively high ____.

A. erode, capacityB. erode, competenceC. deposit, capacityD. deposit, competence

PassageFor question 5

[TB4] Data collected from two different segments of the same stream are shown below.

Segment	Length of straight-line distance (km)	Length of stream segment (km)
A	2.5	1.5
B	3.5	2.5

I. Segment A is more sinuous than Segment B II. Segment B is likely to be located downstream of Segment A

Question 5

1 pt

Which of the statements above is/are true, if any?

A. I, onlyB. II, onlyC. I and IID. Neither

Question 6

1 pt

Which of these is/are true about Earth’s water and hydrologic cycle?

I. In the oceans, overall precipitation balances overall evaporation II. Most freshwater is contained in glaciers and ice III. Energy from the Sun drives the hydrologic cycle

Question 9

1 pt

Which conditions below most favor valley deepening?

A. A steep gradient with a high base levelB. A steep gradient with a low base levelC. A shallow gradient with a high base levelD. A shallow gradient with a low base level

Question 10

1 pt

Which of the following correctly ranks delta beds from coarsest sediment to finest sediment?

Question 11

1 pt

Atmospheric water content is about what percent of oceanic water content?

Question 12

1 pt

In the Midwestern US, what is the most likely consequence of excessive agricultural demand for groundwater?

Question 13

1 pt

Which of the following would provide the best aquifer?

A. MudstoneB. Fractured graniteC. Gravel mixtureD. Unweathered clay

Question 14

1 pt

What can be concluded about the soil samples?

I. The capillarity of A is greater than that of B II. Surface runoff at B is greater than surface runoff at A

A. I, onlyB. II, onlyC. I and IID. None of these

Question 15

1 pt · select all that apply

Select ALL of the following examples of nonpoint source pollution.

A. Motor oil runoff from highwaysB. Pesticides from adjacent agricultural fieldsC. Wastewater from a factory pipeD. Sedimentation pollution along stream banks

Question 16

1 pt · select all that apply

** ** Select ALL of the following that increase in the downstream direction.

PassageFor questions 17–20

Use the following choices for 17-20. Each choice may be used once, more than once, or not at all.

a. Dissolved load b. Suspended load c. Bed load d. None of these

Question 17

1 pt · select all that apply

** ** Which type(s) of load is/are affected by stream velocity? Select ALL that apply.

A. Dissolved loadB. Suspended loadC. Bed loadD. None of these

Question 18

1 pt

Which type of load is the main contributor to stream turbidity?

A. Dissolved loadB. Suspended loadC. Bed loadD. None of these

Question 19

1 pt

Pebbles and cobbles are most commonly part of which load?

A. Dissolved loadB. Suspended loadC. Bed loadD. None of these

Question 20

1 pt

Chemical pollutants, such as fertilizer, are commonly transported as part of which load?

A. Dissolved loadB. Suspended loadC. Bed loadD. None of these

Question 21

1 pt · select all that apply

Current meters can directly measure which of the following? Select ALL that apply.

Question 25

1 pt

Which of these best describes the formation of kettle lakes?

A. precipitation and hydrothermal fluid collect within a calderaB. melted glacial water fills an alpine depression formed by glacial erosionC. a segment from a meandering river cuts off, forming a crescent-shaped lakeD. an ice block melts in an outwash plain and fills a depression

Question 26

1 pt · select all that apply

Select ALL of the following that apply to oligotrophic lakes.

A. High nutrient concentrationsB. High dissolved oxygen concentrationsC. Generally low in turbidityD. High aquatic plant biodiversity

Question 27

1 pt

When lake waters warm in the summer, dissolved carbon dioxide levels tend to ____ and dissolved oxygen levels tend to ____.

A. increase; increaseB. increase; decreaseC. decrease; increaseD. decrease; decrease

Question 29

1 pt · select all that apply

Select ALL of the following impacts of dam construction on a stream.

A. Increased downstream water temperaturesB. Increased downstream erosionC. Increased upstream erosionD. Increased upstream pollutant accumulation

Question 30

1 pt

The main source of water for bogs is ____, whereas the main source of water for marshes is ____.

Question 31

1 pt

Which of the following, if any, is/are disadvantages to injecting polluted water into a deep well?

I. The polluted water will have a long residence time at depth II. The polluted water can eventually contaminate surface water sources

A. I, onlyB. II, onlyC. I and IID. Neither

Question 32

1 pt

A shallow-water wave on the surface of a lake depends on which of the following?

A. Depth onlyB. Wavelength onlyC. Both depth and wavelengthD. Neither depth nor wavelength

Question 33

1 pt · select all that apply

Select ALL statements that are true about knickpoints.

A. Tectonic uplift can result in knickpoint formationB. Knickpoints can be created as a result of glacial activityC. Knickpoints are key features of graded streamsD. Knickpoints are features contained within V-shaped valleys

Question 34

1 pt · select all that apply

Select ALL statements that are true related to the cross-section above.

A. The diagram represents the initial stage of open-system pingo formationB. The pingo that will form will be a result of hydraulic pressureC. The cross-section indicates an area with abundant groundwater supplyD. The permafrost likely exists as a continuous layer below the sands

Section 2

Question 41

1 pt

Which point on the stream profile has the highest stream velocity?

A. distance from A: 8 m, depth: 1 mB. distance from A: 14 m, depth: 2 mC. distance from A: 15 m, depth: 6 mD. distance from A: 18 m, depth: 3 m

Question 42

3 pts

** ** Assuming that the average velocity of the stream is 5 m/s, calculate the flow rate of the stream. Show your work.

Question 43

1 pt

Is the point bar located at the left side or the right side of the stream profile? Is the sediment at a point bar likely to be well sorted or poorly sorted?

Question 44

2 pts

Suppose the base level of the stream dropped. Would the stream discharge increase, decrease, or remain unchanged? Briefly justify your answer.

PassageFor questions 45–47

Questions 45 to 51. Refer to Image G, a topographic map for questions 45-47. The 50-foot contour line is labeled. The contour interval is 10 feet.

Question 45

2 pts

Indicate whether point A is located upstream or downstream of point C. Briefly justify your answer.

Question 46

1 pt

Suppose the water table depth at point B is 10 feet below the surface. State one possible whole number value of the water table elevation at point B.

Question 47

1 pt

On some months, an ephemeral lake can form at point B. Briefly describe the meaning of any clues on the topographic map that may lead to this inference.

PassageFor questions 49–50

The following data table shows the precipitation (P) and potential evapotranspiration (E_p) (in mm) for each month in the region.

Month	Jan	Feb	Mar	Apr	May	June	July	Aug	Sept	Oct	Nov	Dec
P	73	55	34	23	17	23	31	38	43	55	63	77
E_p	29	33	56	85	135	147	156	151	122	88	62	41

Question 49

1 pt

During which month does the groundwater begin to recharge again?

Question 50

1 pt

Assuming precipitation and evapotranspiration are the only inputs and outputs to the ephemeral lake, during which month is the lake level likely to be the highest?

PassageFor questions 52–53, 54a, 55

Questions 52 to 56. Refer to Image H, a cross-sectional profile of a typical floodplain. Some features are labeled; assume all features are formed naturally.

Question 52

3 pts

** ** Identify the features x, y, and z. Assume feature z is NOT part of a lake. (Hint: Feature x is a landform corresponding to the purple surface - NOT "floodplain," y is NOT "riverbank," and there is a specific name for feature z).

Question 53

1 pt

Write the letter(s) of the features (x, y, z) which formed as the direct result of flooding.

Question 54a

1 pt

Suppose zone x is designated the 200-year floodplain. What is the probability of the occurrence of a flood that affects zone x each year? Give your answer as a percent.

Question 55

1 pt

Channelization is one approach to controlling floods. Channels that are built to minimize flooding risk are designed to ____ stream velocity and ____ cross-sectional area.

A. reduce; reduceB. reduce; maximizeC. maximize; reduceD. maximize; maximize

PassageFor question 61

Questions 57 to 62. Refer to Image I, a cross section with rock units shown. The blue surface denotes the water table, and the green dashed line denotes the potentiometric surface. Wells A, B, C, and D are labeled, and w, x, y, and z refer to geologic contacts along a steep slope.

Question 61

1 pt

If groundwater is always being pumped upward from a well at a nonzero rate, which diagram(s) best show the position of the water table (indicated by the dashed lines)?

A. Diagram 1B. Diagram 2C. Diagram 3D. Diagram 1 or 3, depending on the pumping rateE. Diagram 1 or 3, depending on the hydraulic conductivity of the nearby rock

PassageFor questions 63a, 63b, 64–65, 66a, 66b

Questions 63 to 66. Lakes have several physical and chemical properties.

Question 63a

1 pt

Consider a mid-latitude dimictic lake (a lake that mixes twice a year). Let the epilimnion temperature and density of the lake be T_E and ρ_E, and the hypolimnion temperature and density of the lake be T_H and ρ_H, respectively. During the winter, which of these is true about the temperature?

A. T_E > T_HB. T_E < T_HC. T_E = T_H

Question 63b

1 pt

A. ρ_E > ρ_HB. ρ_E < ρ_HC. ρ_E = ρ_H

Question 64

1 pt

In a dimictic lake, during which season(s) is dissolved oxygen content greatest in the hypolimnion layer?

Question 65

1 pt

The total phosphorus content in a lake is ____ related to the chlorophyll a content and ____ related to the total light levels in a lake.

A. directly; directlyB. directly; inverselyC. inversely; directlyD. inversely; inversely

Question 66a

1 pt

** ** Sometimes, waves have been observed to oscillate back and forth in lakes. What is the name given to this type of wave?

Question 66b

2 pts · select all that apply

** ** Sometimes, waves have been observed to oscillate back and forth in lakes. Select ALL of the true statements regarding this phenomenon.

A. These waves are primarily driven by pressure differencesB. These waves are primarily driven by tidal forcesC. These waves are primarily wind-drivenD. These waves typically last for a few minutesE. These waves can cause lakeshore flooding

Question 67

2 pts

** ** Positive feedback loops amplify or enhance changes, whereas negative feedback loops reduce or dampen the initial change. Classify the feedback loop between soil moisture content and evapotranspiration as a positive or negative feedback loop, and briefly justify your answer.

Question 68a

1 pt

Is glacial sediment well or poorly sorted? How does the sorting affect the hydraulic conductivity of the sediment?

PassageFor question 68a

Past glaciation events can have a significant impact on the hydrology of an area.

Question 68b

1 pt

Based on the figures, what is the relationship between bog and marsh density and whether the area has been affected by glaciation?

Question 68c

1 pt

Does the dark purple shading in Image K indicate low-order dominated or high-order dominated stream connectivity?

Question 68d

1 pt

Do streams south of the glacial boundary have more or less tributaries than streams north of the glacial boundary? Are watersheds south of the glacial boundary more well drained or less well drained than those north of the boundary?