Grupo | Índice | Ecuación/Descripción | Indicators |
1 | NSF-WQI (EU) (Brown et al. 1970) |
SNF-WQI: Water quality index according to the U.S. National Sanitation Foundation; a number between 0 and 100 SIi: Quality of the i-th parameter. A number between 0 and 100; depending on concentration or measurement (analysis result). Wi: Weight corresponding to the i-th parameter set according to its importance for the overall conformation of quality; it is a number between 0 and 1. | Temperature, pH, dissolved oxygen, biological oxygen demand, turbidity, total solids, faecal coliforms, nitrates and total phosphates |
Dinius-WQI (EU) (Dinius 1987) |
Ii: Variable sub-index Wi: Weighted weight for sub-index i. | Temperature, pH, dissolved oxygen, biological oxygen demand, nitrates, colour, conductivity, alkalinity, hardness, chlorides, total coliforms and faecal coliforms. | |
CETESB-WQI (Brasil) Rojas-WQI (Colombia) |
Wi: Weight or percentage assigned to the i-th parameter Ii: Sub-index of i-th parameter. | Temperature, pH, dissolved oxygen, biological oxygen demand, turbidity, dissolved total solids, faecal coliforms, total phosphorus and total nitrogen. | |
| CCME-WQI (Canadá) DWQI (EU) |
Scope (F1): Percentage of parameters that exceed the standard. Frequency (F2): Percentage of individual tests for each parameter that exceeds the standard. Amplitude (F3): magnitude by which each parameter that does not comply exceeds the norm. | F1 F2 F3 |
3 | U-WQI (Europa) (Boyacioglu 2007) |
Wi: weight or percentage assigned to the i-th parameter Ii: i-th parameter sub-index. | Cadmium, cyanide, mercury, selenium, arsenic, fluoride, nitrate-nitrogen, DO, BOD5, total phosphorus, pH and total coliform. |