in Port Vila Bay
Day: Friday, July 30, 2021
Each site that we monitor has an icon to indicate the likelihood of pollution:
Pollution is unlikely.
Enjoy your swim!
Pollution is possible.
Pollution is likely.
Avoid swimming today!
It’s tricky to provide up-to-date information on water quality when bacterial results are available two days after we collect samples.
We overcome this challenge by predicting the likelihood of pollution using rainfall data.
To do this, we analysed the rainfall and bacterial data collected over the last five months to determine the rainfall thresholds for each swimming location. The rainfall threshold is the amount of rain that falls before the number of bacteria in the water reaches a level that means the water is polluted.
We base on the rainfall forecast from Port Vila, near each monitoring site. We compare the forecast amount of rain near each swimming site with its precipitation threshold to determine the probability of pollution as shown below:
Unlikely: precipitation is below the threshold and pollution is unlikely.
Possible: Precipitation exceeded the threshold, but not by much. Pollution is possible.
Likely: Precipitation has exceeded the threshold and pollution is likely.