This is the third post in a series by Ralph Pantozzi, one of the 2024-25 Albert Einstein Distinguished Educator Fellows at the Library of Congress.
In the wake of repeated flooding disasters, Congress passed the National Industrial Recovery Act of 1933. The act included funds to fight soil erosion, and efforts were directed to data collection and mapping so that informed actions could be taken.
The process of statistical problem-solving, particularly with respect to the environment, is a cycle of collecting, recording, analyzing, and communicating conclusions about data. Analyzing a map, such as those created to document erosion during the 1930s, provides an opportunity to think about how the statistical problem-solving cycle can be fueled by this type of visual.
Ask students to examine this portion of a map of Tennessee (full version here). Ask:
- Describe what you observe.
- What information can you gain from the map, and what questions does it leave unanswered?


One point of curiosity may be how little, slight, moderate, severe, and “destroyed” are defined. Are these technical terms, and if so, what measurements are part of the definitions? Students may wonder how the data was collected, or how the boundaries were determined. Ask your students to consider how the presentation of this data might be used as part of a decision-making process to address erosion.
The map was constructed with the help of aerial photography, ground-level data collection, and mathematical calculations. Compare the previous map with this one, created in 1980. With your students, take time to examine the graphical, numerical, symbolic, and text elements that are part of the map.



Some potential questions of interest:
- How was this data collected? How precise is the information?
- Why might the information about erosion have been presented in grid squares?
- Was aerial photography still involved? Why was a grid size of 50,000 feet used?
- Why were these ranges of tons per acre per year chosen?
- What calculations might have been performed to arrive at these numbers, and what calculations might you want to make with the numbers provided?
- What does an erosion map look like today? How is the data collected?
Erosion continues to contribute to flooding today. Collecting enough data, and the right data, to make valid and reliable predictions continues to be a challenge. When students encounter data in their lives, the example of erosion can help them think about the connection between data and action. How much is data is enough? How does its presentation affect what decisions are made?
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Comments
Thank you for another great resource for my middle-school social studies class. I’ve added it to my Great Depression collection. Good, too, for cross-curricular with science and math.