In this lab, we’ll focus on tree rings and their uses in reconstructing the streamflow of rivers to model past activity. Specifically, we can collect tree rings from a region and evaluate how current streamflow compares to streamflow of the past. The ability to place current hydrology of a region within the context of long-term hydrologic activity is exceptionally powerful in discussions of things like water resources, policies, security, and water rights.
Streamflow Part I — The TreeFlow Platform
Much research has been done by scientists all over the world using tree rings to reconstruct hydroclimate and streamflow. Dr. Connie Woodhouse at the University of Arizona, Tucson is a dendrochronologist who specializes in streamflow reconstructions, and has built the TreeFlow data platform. The work represented on this website showcases the international collaboration and dedication to this subfield of Geography.
Please go to the following website to begin the lab www.treeflow.info, and follow the steps outlined below.
· Explore the home page of the TreeFlow website in general – scroll through the pages and links, see what’s available up front at a first glance
· Click on the “Background” tab on the left-hand side of the page. Read through the Top 10 things you need to know (you may need to scroll a little bit down the page to find these). The powerpoint slides available provide further details and I strongly encourage reviewing them for deeper learning and engagement.
· Click on the “Basin Data Access” tab on the left-hand side of the page. Select the Pacific Northwest area on the basin map, which will bring you to all of the reconstructions available on this platform for this region.
· Read through the text provided and scroll down the page until you see the available reconstructions to look through…. Note: more streamflow reconstructions are created every year, so this is not a complete list!
· Stay on this page to begin Part II!
Streamflow Part II – Snake River at Jackson Lake Dam
Submit a document that includes the following items upon submission – be sure to follow the steps and prompts below as you create plots and answer questions:
1. Click on the link for the Snake River at Jackson Lake Dam Streamflow Reconstruction Page and build two quick reference tables (an Excel spreadsheet works great here) with the following information:
a. One with the descriptive stats for both the observed and reconstructed flow periods (provided in the metadata)
b. One with the statistics for calibration and validation
2. Download the “snakemoran.xls” data file from the TreeFlow.info website and make two scatterplots:
a. One plot showing both the observed and reconstructed streamflow data for the entire time period (1591-2005)
b. One plot showing both the observed and reconstructed streamflow data for only the time period of observed data (1910-2005)
c. Be sure to title and appropriately label the axes of each plot and provide a legend. You may use whatever graphing software is most comfortable for you, but I strongly encourage Excel.
3. How do the observed and reconstructed streamflow trends match up over the 1910-2005 period? What does the value of the explained variance in the calibration period (1910-2005) tell you about the strength of the relationship between the tree rings and streamflow in KAF? Hint: the closer an R2 value is to -1 or 1, the stronger the relationship. A value of 0 indicates no relationship at all.
4. What are some things that make reconstructing streamflow in the Upper Columbia River basin difficult?
5.How does current streamflow activity compare within the context of the entire available record?
Streamflow Part III — Applications
Please read Lost Cities and Climate Change by Kate Marvel. attached
6. How has climate change impacted civilizations in the past? Use and cite the article as needed for your answer here.
7.Based on what you learned from exploring