Unit 8. Impacts of Extreme Hydroclimatic Events
Unit 8 covers the basics of hydroclimatic extreme events with a focus on floods and droughts. Topics include introduction to floods and droughts, impact of urbanization on extremes, how to understand and predict extremes, how to tackle them (management strategies), and elements of urban climate resilience. The teaching strategy is designed with short and divided lectures filled with discussion questions and a group activity. Students will be working with time series flow data for statistical analysis of extreme events.
After completing Unit 8, students will be able to:
- Define the meaning and explain the characteristics of extreme events (floods and droughts)
- Collect and and perform statistical analysis on geoscience data
- Develop the chart for predicting extremes
- Recognize the usefulness of geoscience data in engineering design and application
- Evaluate and argue potential measures to deal with extremes
- Reflect on key elements of the resilient urban water system
Context for Use
This lesson is designed for use in mid- to upper-level undergraduate courses of engineering and geoscience disciplines. It can be adopted in hydrology, engineering hydrology, or water resources-related courses. There is no discipline-specific prerequisite required since the science content is basic and fundamental in nature. The lesson 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 out of class as a class assignment.
Description and Teaching Materials
Read/Scan the following articles on flood frequency:
- 100-Year Flood - It's all About Chance poster from USGS
- The 100-Year Flood Fact Sheet 229-96 from USGS
- Floods: Recurrence intervals and 100-year floods (USGS) from USGS Water Science School
Go over the pre-class presentation slides (PowerPoint 2007 (.pptx) 521kB Sep21 16) and complete the Pre-Class Assignment (Microsoft Word 2007 (.docx) 28kB Sep21 16). These files 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) Fundamentals of floods, droughts, urban resilience
(25 min) Flood planning activity with Rational Method
(20 min) Drought analysis
- Before class, the instructor should go to the PRISM Climate Data website (more info) and
- print out the most recent year's annual precipitation map for the United States
- print out the 30-year normal precipitation map for the United States
- Divide class into groups and give each group the two maps. Have them look at the recent year's precipitation compared to the 30-year average and decide what parts of the country might be in "drought"
- Then, the instructor can pull up the current drought monitor on the screen and talk about what contributes to drought declaration and severity of drought
(10 min) Wrap-up and general discussion questions for reflecting on what was learned (metacognition)
Initiate classroom discussion using Think-Pair-Share approach (and collect group responses). Example discussion questions are:
- What do we mean by "doing a statistical analysis" for extreme events and why it is necessary?
- How does climate change affect the current understanding of and potential measures to tackle extreme events?
- What are your thoughts on how the urban system can be more resilient to uncertain extreme events?
Teaching Notes and Tips
Students may have difficulty understanding some of the new terms such as frequency analysis, return period, exceedance probability, etc. It is advised to explain the basic meanings of new terms as they appear.
- Pre-class assignment (50% weight)
- Notes of Think-Pair-Share group work (50% weight)
- Excellent: >90%; Very Good: 80–90%; Good: 70–80%; Poor: 60–70%
References and Resources
Konrad, C.P. 2003. Effects of urban development on floods. U.S. Geological Survey Fact Sheet FS-076-03 .
Tallaksen, L.M. and van Lanen H.A.J. 2004. Hydrological Drought: Processes and Estimation Methods for Streamflow and Groundwater. Volume 48 of Developments in Water Science. ISSN 0167-5648. Gulf Professional Publishing. 579 pages.
Tyler, S. and M. Moench. 2012. A framework for urban climate resilience. Climate and Development 4(4): 311-326.