Unit 2. Urban Hydrology
After completing Unit 2, students will be able to:
- Compare and contrast natural versus urban water cycle
- Define the components of the urban water cycle
- Explain the spatial and temporal variability of the water cycle
- Calculate water budget components
- Recognize and quantify the impact of urbanization on surface water
Context for Use
Unit 2 is designed for use in mid-to upper-level undergraduate courses of engineering and geoscience disciplines. It can be adopted in hydrology, engineering hydrology, water resources, or environmental science related courses. There is no discipline-specific prerequisite since the science content is basic and fundamental in nature. Pre-class reading materials (an article from Springer) and videos (YouTube) are available as web links. The unit could also be adapted for use in an online setting.
The activity is structured around a 1-hour 15-minute class period with several hours of supporting work outside of class including pre-class readings and a post-class assignment.
Description and Teaching Materials
Pre-Class Reading and Video
View the videos:
Complete the pre-class work and quiz (Microsoft Word 2007 (.docx) 30kB Sep21 16). This file can ideally be placed under the Online Course Management System such as BlackBoard or course website or can also be administered in the classroom at the start of the class.
(20 min) Topic 1: Natural hydrologic cycle versus urban water cycle
Introduce the concept of the urban water cycle within the large hydrologic cycle.
Initiate classroom discussion using the Think-Pair-Share approach. In this approach, each student will write answers, discuss in group (one or two other students sitting nearby, or groups can be made), and finally share to the class once instructor calls them to do so. Example discussion questions (also provided in the presentation slides) are:
- What are major hydrologic processes? Name at least five of them.
- What are the major hydrologic processes which are affected by urban infrastructures? What do you think is /are the most affected process(s) and why?
(30 min) Topic 2: Water budget analysis
Introduce the concept of water budget in the hydrologic cycle and complexity of dealing with various units in water budget calculation. Solve an example problem via facilitating a Faculty-coached In-class Problem Solving session where students will be divided into groups and immediately apply new information in the faculty presence.
(15 min) Topic 3: Impact of urbanization on surface runoff
Illustrate how built systems accelerate water conveyance mechanisms. Introduce an example problem on water balance and urbanization impact.
Discussion question for this topic: What are the approaches of water management to reduce peak runoff for sustainable urban development? How do they help?
(10 min) Mind Maps
Pull out Mind Map started in Unit 1 and have students add new concepts to their system.
Teaching Notes and Tips
Students may have difficulty understanding some of the new terms such as evapotranspiration, groundwater, average precipitation (monthly vs. annual vs. daily), etc. It is advised to explain the basic meanings of new terms as they appear.
More information could be added in the pre-class reading materials but it is advised to keep it within 30 minutes of reading time.
Divide the class into groups of three students and introduce and hand out the assignment. The assignment is to conduct a water balance study of a catchment
- Unit 2 Assignment (Microsoft Word 2007 (.docx) 24kB Sep21 16)
- Unit 2 Student Handout for USGS data download (Microsoft Word 2007 (.docx) 1.6MB Sep21 16)
- Pre-class Quiz (20% weightage)
- Group assignment due in a week (80% weightage)
- Excellent: >90%; Very Good: 80-90%; Good: 70-80%; Poor: 60-70%
References and Resources
Booth, Derek B. 1991. Urbanization and the Natural Drainage System-Impacts, Solutions, and Prognosis. The Northwest Environmental Journal 7(1): 93-118.
California Water & Land Use Partnership. "How Urbanization Affects the Water Cycle," Sacramento, CA, 2014.
Sowby, Robert B. 2014. [link https://blog.nationalgeographic.org/2014/03/19/the-urban-water-cycle-sustaining-our-modern-cities/ 'The Urban Water Cycle']. Posted on Water Currents on March 19, 2014. National Geographic.
Welty, Claire. 2009. Chapter 2: The Urban Water Budget. In: The Water Environment of Cities (Ed. Lawrence A. Baker). Springer.