Engage:
Show videos and satellite imagery of recent hurricanes in New York. (See Resources section.) You could also view the video Hurricane! by NOVA or another documentary about a recent hurricane (Sandy, Irene, Katrina).
Show photos of recent flooding in Dutchess County. Encourage students to share their personal experiences and thoughts. (See ‘Flooding photos’ PowerPoint below.)
Explore:
Students will begin by reading a background article (attached at the end of this lesson plan) on the impacts of flood events based on a local flood in Dutchess County in April 2007. This can be given for homework the day before or done in class.
Then, students will use data from 2 different floods to explore the changes that occur to streams during and after a flood. Students will use the Hurricane Floyd data set as well as data from the April 2007 storm to understand the impact of a flood on local waterways, creating two different graphs based on these data. Students should pay particular attention to the amount of time it takes different types of rivers to recover to normal flow after a storm of this magnitude. There is also an extension that provides historical peak flow data from Wappinger Creek at Red Oaks Mill, giving students a chance to see the difference between the two storms and other historic flood events.
The data for this lesson are found in the resources section.
Explain:
Predictions from the 2007 Intergovernmental Panel on Climate Change (IPCC) indicate that large, flooding storms will increase in intensity in northeastern North America. These types of storms could be hurricanes, nor’easters, blizzards and large storms in general. It isn’t clear yet whether the frequency of hurricanes will change. The number of hurricanes varies from year to year and ocean to ocean, but on average, there are about 6 hurricanes in the Atlantic Ocean each year.
Hurricane frequency and intensity varies on a natural cycle of 20-30 years. Floods caused by these storms can be devastating. In this lesson, students will investigate 2 different flooding storms in Dutchess County. These 2 storms occurred at different times of the year, which made a tremendous difference in the impact of the storms. In addition, the precipitation that caused the flooding occurred over different time scales. Normally a precipitation event causes stream flow to increase rapidly and then decrease in a skewed fashion, resulting in a prolonged ‘tail’ of flow as the stream recovers. The Hurricane Floyd flood (September 1999) shows this pattern, but the April 2007 flood does not. The April storm occurred during a time when the ground was saturated, so there was no room for additional moisture in the ground or in the water table. The April 2007 storm was a nor’easter that fell as rain instead of snow. Future global change may bring more of these late season nor’easters that in past years would have fallen as snow. The September 1999 storm occurred after a long summer, and there was plenty of room in the soil and groundwater to absorb this large event. Thus, the peak flows and resulting devastation from the April event surpassed the September event, even though there was more rain in the September 1999 event.
Students should read predictions of storm intensity under various global warming scenarios. “Confronting Climate Change in the Northeast” by the Union of Concerned Scientists includes two relevant sections: pgs 15-31 explains the impacts on coastal systems, while pgs 62-65 explains the impacts on water in the northeast. The report can be downloaded at: https://www.ucsusa.org/resources/confronting-climate-change-us-northeas…; Students can also use the following NASA Earth Observatory article to gather more information about hurricanes: https://earthobservatory.nasa.gov/features/Hurricanes
Extend:
Students can research the relationship between land use and storms, specifically the connections between the 2006 tsunami and loss of mangroves as well as Hurricane Katrina and wetland loss.
Evaluate:
Students should submit their graphs and answers to the accompanying questions.
Additional Resources:
Hurricane Sandy images, info, data, and analysis (NASA): https://www.nasa.gov/mission_pages/hurricanes/archives/2012/h2012_Sandy…
Hurricane Floyd images (NASA): https://earthobservatory.nasa.gov/features/FloydIntro-hurricane-floyd
Regional Highlights from the Third National Climate Assessment Climate Change Impacts in the US, 2014 Northeast: https://www.globalchange.gov/sites/globalchange/files/Regional_NE_V4.pdf
Hudson River Mile Map: https://www.dec.ny.gov/docs/remediation_hudson_pdf/hrmilesmap.pdf