Overall Health Index

The Guanabara Bay report card compares 5 indicators for the Bay (dissolved oxygen, biological oxygen demand, total phosphorus, dissolved inorganic nitrogen, fecal coliform) and 5 indicators for the Basin (dissolved oxygen, biological oxygen demand, orthophosphate, dissolved inorganic nitrogen, turbidity) to scientifically derived thresholds or goals. These indicators are combined into two Water Quality Indices (one for the Bay and one for the Basin). The data was provided by INEA.

How is it measured?

Each station has an average water quality index value. The most recent data used in the report card is from 2013 - 2015. The scores for all stations in each region of the Bay or Basin are averaged together. There are five regions in the Bay and six regions in the Basin. The regions are area weighted to come up with the overall scores. Data was provided by INEA.