Water Quality Index Calculator
Calculate a simplified water quality index (WQI) from dissolved oxygen, pH, turbidity, and temperature parameters.
Water Quality Index
74.3 WQI
Water Quality Index vs Dissolved Oxygen Score
Formula
## How to Calculate Water Quality Index The WQI combines multiple water quality parameters into a single score. ### Formula **WQI = DO(0.30) + pH(0.15) + Turbidity(0.20) + Temp(0.15) + Nutrients(0.20)** ### Rating Scale - **90-100**: Excellent - **70-89**: Good - **50-69**: Medium - **25-49**: Bad - **0-24**: Very Bad Each parameter is first converted to a 0-100 sub-index score based on its measured value.
Esempio Risolto
A water body with DO=75, pH=80, Turbidity=70, Temperature=85, Nutrients=65.
- 01DO: 75 * 0.30 = 22.5
- 02pH: 80 * 0.15 = 12.0
- 03Turbidity: 70 * 0.20 = 14.0
- 04Temperature: 85 * 0.15 = 12.75
- 05Nutrients: 65 * 0.20 = 13.0
- 06WQI = 22.5 + 12.0 + 14.0 + 12.75 + 13.0 = 74.3 (Good)
Domande Frequenti
What does the WQI measure?
The Water Quality Index consolidates multiple measurements into a single number indicating overall water quality. Higher scores indicate better quality for aquatic life and human use.
Why is dissolved oxygen weighted most heavily?
Dissolved oxygen is the most critical parameter for aquatic life. Most fish need DO above 5 mg/L. Low DO indicates pollution and eutrophication.
What causes low water quality?
Common causes include nutrient runoff (fertilizers), sewage discharge, industrial pollution, sediment erosion, thermal pollution, and acid rain.