Setup, Data Collection & Reporting — Student Field Guide

1. Equipment you need

Use the same equipment and method for the whole experiment. You need a clean plastic container with straight, vertical sides, a ruler marked in millimeters, a permanent marker, and a stable base so it cannot tip. A bubble level and a phone camera help but are optional. The best container is a cylinder — round, with a smooth, level rim, an opening at least 10 cm across, and 15–20 cm deep so it will not overflow in heavy monsoon rain. Do not use narrow-necked bottles, curved or sloping sides, funnels, cracked containers, or lids; a cut soft-drink bottle is usually a poor choice because its sides curve near the bottom.

2. Choosing the location

The opening must receive rain directly from the sky — nothing above it, nothing splashing in. A good spot has a clear open view of the sky and is away from roof edges, gutters, drainpipes, overhanging branches, walls, and floodwater. Apply the distance test: place the collector at least twice as far from an obstruction as the obstruction rises above it (a wall 2 m higher → at least 4 m away; a tree 5 m higher → at least 10 m away). If runoff from a roof, tree, wall, pipe, or flooded surface can enter the collector, the location is invalid.

3. Daily measurement and reset

Check the collector every day at the same time (8:00 AM Bangladesh time is recommended); each reading covers all rain since the previous reset. Inspect before touching, note any debris, read the depth in millimeters at eye level, record the date/time/depth and any problems immediately, then empty completely and reset level and secure. On dry days record 0.0 mm — never leave it blank (a blank means "nobody checked"; a zero means "I checked and there was no rain"). Visible moisture too small to measure is Trace (less than 1 mm), not 1 mm.

4. The math

Because the sides are straight, the water depth is the rainfall — no conversion needed (18 mm deep = 18 mm of rain). If your coordinator asks you to measure by volume instead: Rainfall (mm) = (Volume in mL × 10) ÷ Opening area in cm², where Opening area = π × (diameter ÷ 2)². Stick to one method for the whole experiment.

5. Special situations

Overflow: report "actual rainfall greater than container capacity," give the capacity in mm, and mark it incomplete — never guess. Missed observation: measure as soon as you can, record the actual time and how many hours it covers. Disturbed container (knocked over, tampered with, runoff entered, opening blocked): mark it Invalid. During big storms you may empty more than once a day and add the readings. Never replace a missing or invalid reading with a guess.

6. Data quality: the four labels

Every daily observation gets exactly one label — Valid (protocol followed, no known problem), Questionable (a minor issue such as slight tilt or debris), Invalid (contaminated, disturbed, or unreliable), or Missing (no observation made). Invalid and Missing must never be entered as zero.

7. Your weekly report

Each week submit a station check (registered container and location, level opening, any changes, a current photo), seven daily entries (date/time, whether you checked, measured mm, reset and level status, overflow/disturbance/runoff/debris flags, a photo, a quality label, and an explanation for anything not Valid), and a weekly summary (total valid rainfall, rainy vs. zero days, highest daily rainfall, any problems, neighborhood flooding, your confidence level, and an honesty confirmation).

8. Analyzing your data

Weekly rainfall = the sum of valid daily measurements (questionable readings listed separately; invalid and missing never added). Compute the average per rainy day, the rainy-day percentage, and the week-over-week change. Roof-water potential: theoretical liters = rainfall (mm) × roof area (m²), and collectable liters = theoretical × efficiency (real systems collect less because of splashing, leaks, dirt, evaporation, and first-flush losses).

9. Safety & checklists

Never climb or go out in dangerous weather — a longer observation period is always acceptable, an injury never is. The guide closes with quick setup, daily, and weekly checklists. Method references: WMO-No. 8 and CoCoRaHS observer guidance.

This is a summary. Download the attached PDF below for the complete, print-ready document. Grades 9–12 · Bangladesh · Student field research — measure carefully, report honestly, learn from local rain.