Project Grade 8 Science
Hollins Row Rain Gauge Network: How Rain Varies by Block
A five-session grade 8 science project in which students build and site rain gauges, log two weeks of storms, and report findings to a fictional stormwater board.
Objectives
- Students will build and calibrate a rain gauge that agrees with a reference gauge within a tenth of an inch.
- Students will collect and log rainfall data from a sited network of gauges over a two-week window.
- Students will construct a scatter plot from their own measurements and describe the association it shows.
Vocabulary
Key words: rain gauge, calibration, siting, air mass, front, scatter plot, association
Teacher overview
Rainfall is usually reported as one number for a whole town, yet a single storm can drop noticeably different amounts a few blocks apart. This project has students build simple gauges, site them by real siting rules, and collect two weeks of their own data across a neighborhood. The driving question is whether one official gauge can speak for a whole neighborhood, and the answer comes from the students' own measurements rather than from a table. The final deliverable is a data report and a short presentation to a fictional stormwater district board.
Project Brief
Driving question: Does one rain gauge tell you what fell across a whole neighborhood?
The client. The fictional Crowmoor Stormwater District maintains one official rain gauge for the Hollins Row neighborhood. The district uses that single reading to decide which storms to study when drains back up. Residents on the low end of Hollins Row say the readings do not match what falls on their street. The district board has asked your class for data. Your teacher will place the class reference gauge at the school, or name a nearby public gauge, to stand in for the district's official gauge.
What you build. Each team builds one rain gauge. It must meet these constraints.
- The container must be straight-sided, so the depth of water inside equals the depth of rain that fell.
- The mouth must be at least 3 inches across.
- The scale must be marked in tenths of an inch.
- The rim must sit level and at least 2 feet above the ground.
- No object may stand closer to the gauge than twice that object's height.
- No purchases. Use classroom supplies and donated containers only.
What you measure. For each storm during the two-week window, record the date, the start and end time, the catch in inches to the nearest tenth, and how many minutes standing water stayed in the marked low spot at your site. Also record what a public forecast says caused the storm, such as a cold front, a warm front, or a stalled boundary. Read gauges only after thunder and lightning have passed, stay out of standing or moving water, and place gauges only where an adult has given permission.
What you turn in. A four-page data report and a labeled neighborhood map, presented to the district board in an eight-minute talk. The report must include the gauge design and calibration result, the siting rule and why it exists, the full data log, one scatter plot, one bar chart, a written description of what the data shows, and one recommendation to the board.
Hypothesis. Before any data is collected, each team writes a testable prediction in this form: gauges farther from the official gauge will differ from it by more than gauges close to it. Teams may write a different prediction as long as it names a variable that can be measured.
Milestones
- Session 1: Question, design, and build. Write the team hypothesis. Build the gauge to the constraints listed above. Calibrate it by placing it beside the reference gauge under the same watering can pour. The build passes when the two readings agree within one tenth of an inch. Output: a working gauge and a signed calibration slip.
- Session 2: Siting and mapping. Choose eight sites across the neighborhood, at least one block apart. Check each site against the siting rule about nearby objects. Draw the map with the sites, the streets, the official district gauge, and the marked low spot at each site. Output: a labeled map plus a short written reason for each site choice.
- Session 3: Data collection review. Bring in the logs from the first storms. Check that every row has a date, a start and end time, a catch to the nearest tenth, a standing-water time, and the front or air mass named from a public forecast. Fix any row that is missing an entry, and mark any reading you suspect is wrong. Output: a clean data log with suspect readings flagged and explained.
- Session 4: Displays and analysis. Build a scatter plot with rainfall depth on one axis and standing-water time on the other, using every storm from every site. Describe the association in writing: is it positive, negative, or neither, is it close to linear, and which points sit apart from the rest. Build a bar chart of catch by gauge for the single largest storm. Output: both displays plus a paragraph describing what each one shows.
- Session 5: Report and presentation. Assemble the four-page report and present it to the board. The talk must state the hypothesis, show the two displays, say whether the data supported the hypothesis, and end with one recommendation about how many gauges the district should run. Output: the report, the map, and the presentation.
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Rubric
| Criterion | 1 Emerging | 2 Developing | 3 Proficient | 4 Advanced |
|---|---|---|---|---|
| Gauge design and calibration | The gauge misses two or more constraints and is not calibrated. | The gauge meets most constraints but fails the calibration check. | The gauge meets every constraint and passes the calibration check. | The gauge meets every constraint, passes calibration, and the team explains what a straight-sided container prevents. |
| Siting and mapping | Sites are chosen without reference to the rule. | Some sites follow the rule; the map is missing labels. | All eight sites follow the rule and the map is fully labeled. | All sites follow the rule, the map is fully labeled, and each site choice is justified in writing. |
| Data collection | The log has many missing entries. | The log is mostly complete but some rows lack a time or a weather note. | Every row is complete, including the front or air mass named for each storm. | Every row is complete, suspect readings are flagged, and the team explains what likely caused each one. |
| Displays and analysis | No display, or a display without labeled axes. | One display with labeled axes and no written description. | Both displays are labeled and described, naming the direction of the association. | Both displays are labeled and described, naming direction, closeness to linear, and any point that sits apart from the rest. |
| Report and recommendation | The report omits required sections. | The report includes most sections; the recommendation is not tied to the data. | All sections are present and the recommendation cites the team's own data. | All sections are present, the recommendation cites the data, and the team names what more data would settle the question. |
Differentiation
Support
Give these students a pre-cut container and a printed adhesive scale so the build starts at the mounting step, and pair them with a partner for the calibration pour. Provide the data log as a table with the columns already headed and one row filled in as a model. For milestone 4, supply graph paper with both axes already scaled and labeled.
Extension
Ask these students to add a third variable to the scatter plot by coloring each point according to the front that caused the storm, then write a paragraph on whether cold fronts produced a different pattern than warm fronts in this data set. They should also state how many more storms they would need before trusting that pattern.
ELL supports
Pre-teach "gauge," "calibrate," "site," "front," and "association" with a labeled photograph of a properly sited gauge and a poorly sited one under a tree. Provide the log sheet with column headings in the student's first language alongside English. For the presentation, allow the team to read from a script and to point to the displays rather than describing them from memory.
Extensions
Teams compare their two-week totals with the readings from the district's single official gauge for the same storms and calculate the largest difference they found. They then write a one-page letter to the board arguing for or against adding gauges, using their own numbers rather than the general claim that more data is better.