Unit 4: Hurricane Impacts

After completing this unit students will be able to:

• Identify specific inland hazards that can accompany hurricanes (landslides, flooding, damage to infrastructure), especially inland.
• Observe and quantify changes by using before and after storm images.

This unit relates to the following Earth Science Literacy Big Ideas:

• Earth scientists use repeatable observations and testable ideas to understand and explain our planet.
• Learning about some of the real data that scientists use to determine types and extent of impacts and damage (for example, stream discharge, aerial photos, satellite images, airborne lidar), and how these data are combined, are important aspects of the process of science.

This unit provides in-depth information and comparisons for hurricane impacts on the shore and inland. These activities may be used with the Natural Hazards and Risks: Hurricanes module, or as a stand-alone unit on hurricane impacts. The unit may be used in any course discussing natural hazards, or can be modified to fit a variety of earth, atmospheric, and marine science courses. The unit is appropriate for an exploration of impacts in an introductory-level college course or as the basis for more in-depth discussions of on hurricane impacts and measurements for upper-level students. For Activity 4.2, students should be familiar with river discharge and how tributaries feed water into the main branch of a river.

Activity 4.1 Overview of Hurricane Impacts on Inland Environments

Begin by asking students to contribute to a list on the board of the effects of hurricanes. (Write down all answers with no judgment, and save list.)

Present this PowerPoint on terrestrial impacts of hurricanes to highlight the diversity of impacts on communities when a hurricane makes landfall: 4.1 slides on hurricane impacts (PowerPoint 2007 (.pptx) 25.2MB Sep26 14)

Use the assessments below as discussion points, think-pair-share, or in-class writing/quiz.

End by returning to the list of hurricane effects. Ask students to revise the list (write down the additional answers in another color or column), and then ask students to write on their own what surprised them most about the effects of hurricanes.

Activity 4.2 Observations of Coastal Change (North Carolina)

First, introduce LIDAR data and how they are used in geosciences, with these slides: Introductory slides about coastal change dataset (PowerPoint 1.3MB Aug26 14). Use the sample data set PDF format for LIDAR intro slides (Acrobat (PDF) 1.3MB Aug27 14) to show pre-storm topography, post-storm topography, and changes (difference between the two).

Then, have students work on one or more of the example sites (below, both PowerPoint and PDF formats are included) making their own observations. Based on a US Geological Survey (USGS) website and data about changes from Hurricane Irene, the files below include images of the data that students can use in print or electronic format. Each of the slide sets includes an overview map, an aerial photograph pair of before and after the storm, and four co-registered images of the topography and change. For assessing student results, we also included the USGS caption with main changes. Note that on the difference images, values that are warm (positive) are actually erosional features due to the way the image differencing was done.

• Recommended files: Data set for Rodanthe (PowerPoint 1.5MB Aug26 14) , PDF format data set for Rodanthe (Acrobat (PDF) 1.4MB Aug27 14).
• Other files:
  • Data set for Ocracoke site (location 2) (PowerPoint 861kB Aug26 14), PDF format data set for Ocracoke, NC (Acrobat (PDF) 802kB Aug27 14)
  • Data set for Hatteras village, NC site (location 3) (PowerPoint 1MB Aug26 14), PDF format data set for Hatteras Village, NC (Acrobat (PDF) 991kB Aug27 14)
  • Data set for Pea Island National Wildlife Refuge, NC site (location 5) (PowerPoint 1.3MB Aug26 14), PDF format data set for Pea Island NWR, NC (Acrobat (PDF) 1.2MB Aug27 14)

Activity 4.3 Observations of Inland Flooding Impacts (New Jersey)

This presentation (PowerPoint 2007 (.pptx) 7.6MB Aug26 14) shows data from USGS river gages in New Jersey and how Hurricane Irene (and somewhat Hurricane Lee and another storm the next month) affected them. The data are presented as relative to previous historic records and show where Irene set new river discharge records. One set of rivers, the Delaware, Passaic, and Pompton, are presented. The Passaic and Pompton show an intriguing relationship: the tributary, the Pompton River, has a higher peak discharge from Irene than the gauge downstream on the Passaic. This is a good example of having students think about preconceived notions of how tributaries and rivers operate. Through examining, even qualitatively in the presentation, the volume of the discharges it is clear that the downstream Passaic River has more discharge than the tributary feeding it, the Pompton.

This unit (Activities 4.1, 4.2, and 4.3) is designed so that most instructors can either choose one of these example activities or divide the class into groups where different groups each do one of the analyses and then report back.

1. How would experiencing above-average precipitation in the weeks before a hurricane affect flooding?
   Show answer
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   Full streams and rivers will not be able to absorb much extra rain from the hurricane, leading to likely flooding.
   
   
2. Examine this image of New York Harbor days after Irene has passed. Describe how Earth operates as a system and how the hydrosphere and atmosphere impact the solid lithosphere: http://earthobservatory.nasa.gov/IOTD/view.php?id=51975
   
   
   Show answer
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   A complete answer should address how the atmosphere releases rain to the lithosphere, which then erodes and sends sediment into the hydrosphere via rivers and back out to sea.
   
   
   Direct students to list the effects of hurricanes (and/or Irene in particular) that students could name before this activity. End by returning to the list of hurricane effects. Ask students to revise the list (write down the additional answers in another color or column), and then ask students to write on their own what surprised them most about the effects of hurricanes.

Additionally, for Activity 4.1

The North Carolina Department of Transportation (NCDOT) held public meetings to present two alternatives for the long-term Rodanthe bridge and gather feedback (January 7, 8 and 9, 2014, in Ocracoke, Rodanthe, Buxton and Manteo): the NCDOT handout has some interesting background and could be modified for a more extensive discussion of community involvement in planning.

Additionally, for Activity 4.2

Students should sketch (or label) the areas of major landscape change due to the storm. Answers will vary by data set. Descriptions of each area's change are included in the notes of the PowerPoint slides, and the following file includes the descriptions of major changes from the USGS website to help the instructor with an example of major changes.

LIDAR Assessment Guide -- private instructor-only file

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• Link to Raw Data at USGS
• http://vimeo.com/28318884
• http://water.usgs.gov/floods/events/2011/irene/
• http://www.jpl.nasa.gov/news/news.php?release=2012-340
• http://water.weather.gov/resources/hydrographs/acyn4_hg.png
• http://google.org/crisismap/sandy-2012
• http://web.archive.org/web/20170513061149/https://nj.usgs.gov/hazards/flood/flood1108/index.html
• http://www.nhc.noaa.gov/surge/
• http://earthobservatory.nasa.gov/IOTD/view.php?id=52059
• http://www.nasa.gov/mission_pages/hurricanes/archives/2011/h2011_Irene.html
• http://motleynews.net/2011/09/02/hurricane-irene-photos-of-before-and-after/
• http://www.youtube.com/watch?v=5Xgu-W4837A&feature=endscreen&NR=1
• http://www.salemstate.edu/~lhanson/gls214/gls214_barrier_isl.htm Supplementary lecture notes and good diagram of barrier island
• Airborne Lidar Processing System (ALPS) Software from USGS
• Wright, C.W. and J.C. Brock. EAARL: A LIDAR for mapping shallow coral reefs and other coastal environments. Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments, Miami, FL, May 2002, Veridian International Conferences, Unpaginated CD-ROM.
• Another resource for similar kinds of data sets (not used in module): http://coastal.er.usgs.gov/hurricanes/sandy/lidar/newjersey.php
• More from SERC about floods and flooding, with background material and how to teach these concepts quantitatively.
• Image of the day from New York Harbor, following Irene (2011)
• Hurricane Irene and landslides near Troy New York New York Geological Survey
• USGS Landslide Hazards Program