Outdoor Exercises return to enviromath
This web page describes three outdoor exercises that we use in our integrated course Six Billion and Counting. Also provided (in pdf format) are student handouts. These exercises were written specifically for Pacific Northwest forests and streams, and the Seattle urban environment. Some modification will be necessary to adapt these exercises to different geographic regions. Links to the exercises are given below.
- Measuring Stream Discharge
- Douglas Fir Biometrics
- Measuring Urban Runoff
1. Measuring Stream Discharge back to top
Description: Students measure stream parameters (width, depth, speed) along two stream transects, and graph a vertical slice through the streams showing variation in depth and speed. They calculate discharge (volume per time) for the streams using two different methods, and compare their results with the discharge measured at a U.S. Geological Survey station nearby; discharge is an important component of fish habitat and flood analysis. The exercise emphasizes unit manipulation, estimates, averaging, and sampling. Field work requires a flow meter/graphing calculator set up, making this activity more dependent upon technology than the others listed at this Web site.
2. Douglas Fir Biometrics back to top
Description: Students measure the heights and circumferences of a sample of Douglas fir trees using simple devices and right-triangle trigonometry. Students then take an exploratory data analysis approach to determine which of several functions best fits the (circumference, height) data. Students extrapolate beyond the data to predict the height of a 700-year-old Douglas fir from its circumference. The exercise focuses on measurement and errors, modeling with functions, correlation, extrapolation and outliers. Inexpensive inclinometers for measuring the angle from the horizontal are easily obtained.
3. Measuring Urban Runoff back to top
Description: Urbanization results in a loss of surfaces that are permeable to rainfall, as roads, sidewalks, driveways and buildings cover and displace native soils and vegetation. Working in small groups, students measure the areas of different kinds of permeable and impermeable surfaces in a city block, using maps provided by the city, and then compile the block data to determine the sample means. An Urban Runoff Index (URI) is developed based on a weighted sum of z-scores for the different surfaces. The project emphasizes samples and populations, units of measurement, means and standard deviations, z-scores, weighted sums, and outliers.
Documents: All documents for this exercise can be found in the Quantitative Reasoning and the Environment Chapter 12 Project