What is the Discharge of the Congaree River at Congaree National Park?

Module by: Mark C. Rains and Len Vacher, University of South Florida

Cover Page by: Len Vacher and Denise Davis, University of South Florida

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This material was originally developed by Spreadsheets Across the Curriculum as part of its collaboration with the SERC Pedagogic Service.


This Spreadsheets Across the Curriculum activity introduces Geology of National Parks students to the discharge and floodplain-forest ecosystem of the Congaree River, which is approximately in the middle of South Carolina. Photos in the module show river at various flood stages. Students will determine discharge from reading values on a graph along a trendline. Students get an opportunity to determine correlations by fitting trendlines to scatter plots with arithmetic and logarithmic scales. The intent of the module is to have Geology of National Parks students make straightforward numerical calculations as they learn about river discharge and how it affects the ecosystem.

This material is based upon work supported by the National Science Foundation under Grant Number NSF DUE-0836566. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

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Learning Goals

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Students will:

  • Construct a rating curve and table to convert from stage height to discharge.
  • Relate discharge on the Congaree River to climatic, geologic, and land-use conditions upstream and outside the park.
  • Understand how the discharge on the Congaree River (especially flood flows) are essential to the health of the floodplain-forest ecosystem.

In the process the students will:

  • Create plots using arithmetic and logarithmic scales.
  • Get practice formatting graphs in Excel: e.g., adding grid lines; adding trendlines, and R2 values.
  • Learn about positive and negative correlation (and correlation vs. causation); linear and nonlinear relationships; power functions and log-log plots.
  • Have the opportunity to learn some surface water concepts: discharge, stage, and flood.
  • See how some surface water quantities can be determined -- namely the discharge and stage height.

Context for Use

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This module is designed for potential use in the Geology of National Parks service course at USF. The course is offered as an online course every semester. It includes readings from Parks and Plates, weekly quizzes based on that textbook, and weekly student activities designed to align the course with the University's general education requirements. This module is intended to be one of those activities, with the specific goal of meeting the gen-ed quantitative literacy dimension.

Description and Teaching Materials

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The module is a PowerPoint presentation with embedded spreadsheets. Click on the link below to download a copy of the module. This will open a read-only PowerPoint slideshow. If you would like to edit the module, save the file to disk. The author's intent was for the file to be used as a slide show.

Optimal results are achieved with Microsoft Office 2007 or later; the module will function in earlier versions with slight cosmetic compromises. If the embedded spreadsheets are not visible, save the PowerPoint file to disk and open it from there.

The above PowerPoint slide show file is the student version of the module. It includes a template for students to use to complete the spreadsheet(s) and answer the end-of-module questions, and then turn in for grading. Each module was created to be the first slide show that the student would view. Therefore the first slide of each show includes instructions. Click on the close button to exit these instructions and see the entire title slide.

An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (vacher@usf.edu) by filling out and submitting the Instructor Module Request Form.

Teaching Notes and Tips

The module is constructed to be a stand-alone resource. It can be used as a homework assignment or lab activity. It can also be used as the basis of an interactive classroom activity. The module has not been implemented yet, so we have no tips from experience. We expect that the module can be completed within a two-hour time frame as an out-of-class activity.


There is a slide at the end of the presentation that contains end-of-module questions. The end-of-module questions can be used to examine student understanding and learning gains from the module.  Answer key for end-of-module questions are at the end of the instructor version of the module.

References and Resources

US National Park Service (NPS)