Scientific report on the hydrology of urban streams and benefits of restoration
Assignment
Write no more than 1500 words. [Note: Tables, figures, captions and reference lists do not count in the word tally].
In Rivers Practicals 2 and 3 you undertook a surveying exercise across an urban stream on the Macquarie University campus. You then processed this data and used the discharge and velocity equations to analyse and quantify the flow velocity and discharge characteristics for this stream. You will be using the skills learnt in these practicals (and the lecture on Stormflow) in this assignment.
In this assignment you will:
1) use the information provided below to undertake calculations of flow velocity and discharge for the channel cross section provided and using three different roughness (Manning's n) values.
2) research the scientific literature using your library database skills to investigate urban stream restoration approaches and their effects on stream flow and storm flow (hydrology). At least 10 scientific references should be used in your assignment including the compulsory reading, Chin et al. (2013).
3) write a scientific report. Only the scientific report is to be handed in to Turn It In. Do not hand in this assignment information and calculation sheet. The Data and Calculations section below should be written up (transferred) to the results section of your report (see section below on report structure).
DATA AND CALCULATIONS - URBAN STREAM CROSS SECTION AND HYDROLOGY
Figure 1 shows a cross section of an urban stream. You will use this cross section to calculate flow velocity and discharge for a range of different roughness (Manning's n) scenarios.
Remember:
Flow velocity equation
V = [(D2/3) x (S1/2) / n], where
V = mean channel velocity (m/s)
D = flow depth (m)
S = water surface slope (m/m; often approximated by the slope of the bed)
n = Manning's roughness coefficient
Discharge equation
discharge = velocity x cross-sectional area
Q = V x A, where
Q = discharge (m3/s)
V = velocity (m/s)
A = cross-sectional area (m2)
Using this channel cross-section, complete Table 1. Channel slope has been provided for you. This table will need to be reproduced as part of the results section of your scientific report.
Table 1 Hydrology of an urban stream at Macquarie University
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Channel slope
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0.005 m/m
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Bankfull channel depth
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Bankfull channel width
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Channel cross sectional area
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Three different Manning's n roughness parameters have been provided in Table 2. Use these to calculate the flow velocity and discharge for scenarios 1, 2, and 3. This table will need to be reproduced as part of the results section of your scientific report.
Table 2 Roughness scenarios, flow velocity and discharge characteristics of an urban stream at Macquarie University
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Manning's n roughness for scenario 1 (smooth stormwater pipe)
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0.007
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Manning's n roughness for scenario 2 (moderate in-channel vegetation)
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0.07
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Manning's n roughness for scenario 3 (woody debris and dense in-channel vegetation)
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0.3
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Flow velocity for scenario 1
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Flow velocity for scenario 2
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Flow velocity for scenario 3
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Discharge for scenario 1
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Discharge for scenario 2
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Discharge for scenario 3
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THE ASSIGNMENT QUESTIONS
1) As part of the introduction - What are the characteristics of stream flow (hydrology) in urban environments?
2) As part of the results - Using the results of your calculations, explain how changing roughness impacts on stream flow hydrology in an urban stream?
3) As part of the discussion - Assume that the aim of urban stream restoration is to reduce flow velocity to improve public safety, minimise sediment erosion and improve physical structure (i.e. geomorphology). What types of restoration/rehabilitation can be undertaken to achieve these aims? [Hint: read Chin et al. (2013) and take a walk around campus for examples (Mars Creek behind Y3A, University Creek between Research Park Drive and Innovation Rd)].
4) As part of the discussion - What might be some additional benefits of undertaking urban stream restoration (e.g. on stream ecology and/or water quality)?
SCIENTIFIC REPORT PRESENTATION
You will present this assignment as a scientific report with appropriate referencing. Below is a rough guide of the proportion of the report that should comprise each section. Your scientific report will comprise the following:
Introduction
- Short literature review on the topic, using an appropriate referencing style.
- You will need to define terms such as urban hydrology. Answer assignment Question 1 as part of the introduction.
- State the aims of the assignment.
Methods
- Brief summary of how you went about calculating the data for your report and the methods you used in your research of the topic.
Results
- You will present the data and calculations you undertook in the section above on Data and calculations.
- You can present this in any way you wish, but good use of figures and tables is critical. Be imaginative! You should reproduce the cross section and tables provided above as a minimum.
- You need to describe, in the text, the values you have calculated and any trends you see in the data and support this with figures (i.e. put the text first!). You should never put a figure or table into a report and then provide no description of what they show. Answer assignment Question 2 in the results.
- Make sure you add titles to your figures and tables and you place these into the correct locations in the report.
- You can choose to include any other information you think is necessary to present the data.
Discussion
- This is where you interpret the data and answer assignment Questions 3 and 4. This should be a coherent body of text with a well argued and researched case (i.e. no dot points).
- You may chose to use subheadings to define each question/section - this is fine.
- To do this section well you will need to relate your answers to the literature and use an appropriate referencing style.
Conclusion
- One paragraph summary of findings.
Reference list (no set length)
- Set out in the style of the journal Geomorphology.
- At least 10 scientific references should be used in your assignment including Chin et al. (2013).