Implement Dynamic Guidelines to estimate Rhein-Swimming Water Quality

[Butanding]

I was always asking myself: When is the best time to swim in the Rhein in Basel.
So i did some research and talked to some officials. Basically, the quality of the Rhein-Water depends on two things:

1. How much did it rain the last days?
2. How much UV-Rays/Sunshine was there the last days?

It would be a cool feature, to see the sum of precipitation over the last 72h in Basel. Maybe in combination with UV-Rays of the Last 72h. Together with an explanation, what makes up for a healthy Rhein Water to swim in.

I could also help you implement it, if you give me a basic lesson on how to add a new tab or wherever you think this could be cool.

A more precise explanation can be found in the annual report on water quality:
https://www.kantonslabor.bs.ch/dam/jcr:5053284a-cd44-490f-9cea-6c44c99aaa1d/2022-Fliesgew%C3%A4sser.pdf

The relevant part is here:

Allgemein kann gesagt wer den, dass längere Schönwetterperioden, verbunden mit intensiver Sonneneinstrahlung, einen positiven
Effekt auf die Wasserqualität haben. Die UV-Strahlen des Sonnenlichts töten Bakterien an der Wasser oberfläche ab. Andersherum nimmt die Wasserqualität nach Gewittern und starken Regenfällen eher ab. Dann nämlich kommt es durch das Aufwühlen des Flussbettgrundes und den Eintrag von Materialien von aussen (Bäume, Blätter, Fäkalien, Abschwemmungen von landwirtschaftlich genutzten Flächen) zu einer vermehrten Belastung mit Mikroorganismen. Ausserdem stellt bei bzw. nach Regenwetterperioden auch
die Siedlungsentwässerung eine wichtige Quelle für die Belastung von Gewässern mit Mikroorganismen dar. Kläranlagen verarbeiten dann nur etwa das Doppelte des bei Trockenwetter anfallenden Wassers, so dass überschüssiges, ungereinigtes Abwasser, das mit viel Regenwasser vermischt ist, in das Gewässer gelangt.

[chrisrickenbacher]

@Butanding thanks for the idea. I was thinking a little about it and did some research:

For the measurement of the sunlight or more the intensity of the sun we could use the daily global radiation value from this datasource: https://data.bs.ch/explore/dataset/100254/table/?sort=date

And the amount of rain from this source: https://data.bs.ch/explore/dataset/100009/table/?disjunctive.name_original&disjunctive.name_custom&sort=dates_max_date

Are you then think about something like a bathing quality with let say three levels like bad, good and perfect?

bathing quality	sun	rain
perfect	global daily radiation over 72h above certain value	72h no more rain then a minimal amount
good	global daily radiation over 72h above certain value	48h no more rain then a minimal amount
bad	else	else

Would that make sense from your point of view?

Do you have any idea what values we should take for:

• global radiation for perfect?
• global radiation for good?
• minimal a mount of rain for a day?

[Butanding]

Hi @chrisrickenbacher
Thanks for your ideas.

Why don't you just use the first source? https://data.bs.ch/explore/dataset/100254/table/?sort=date
As far as I can see, it has both, precipitation and radiation measured in Binningen.

To be honest, it can get quite complex to break down the all the factors into an easy formula.
I will forward your formula to the Department "Badewasserkontrolle" of Kanton Basel Stadt and see what they say.
I would also want to ask them about the 48/72 hours schedule.. maybe we can reduce it to 24/48 hours.
Though i think there is a slight risk, that they won't like the idea of a "simplified" version of their very complex laboratory researches of the Rhein-Water Quality. But let's ask.

Will get back to you when I get a reply.

[chrisrickenbacher]

I build a prototype with the following logic:

dailyRainTreshold = 2 mm
dailyRadiationTreshold = 170 W/m2

If maxRainLast72h < dailyRainTreshold and globalRadiationLast72h > ( dailyRadiationTreshold * 3 ) => perfect
If maxRainLast48h < dailyRainTreshold and globalRadiationLast48h > ( dailyRadiationTreshold * 2 ) => good
otherwise => bad

Now we can observe the result and tweak those thresholds a bit.

[Butanding]

Hi @chrisrickenbacher,
i like your implementation :)
During the last weeks i had some talks with people from the Kanton and they all hated the idea and do not want to give out any information or want to be connected with the project. In my eyes understandable, they are officials and the water quality barometer is just a very loose information with no guarantee.
On the other hand i find it a very suitable tool at hand and i think it has a very vital right to exist.

I would, though, add some more background information on it. Here is some ideas to think about:

1. Maybe add a tooltip explaining the idea and background how you calculate such Water Quality Barometer
2. Reference some of the Studies from the Kanton for annotation, that where the source for the idea of this implementation
3. Maybe give it a different name to reflect the "non liability" of this water quality barometer. For example: "rhygfuehl.ch Wasserqualität" or "Planschqualität" or "Wasserqualitäts-Prognose" or "Wasserqualitäts-Schätzung" or "Wasserqualitäts-Trend" or something alike.

Other than that i really like the idea.. Lets observe a little bit the quality over the next weeks and see how it evolves.

How do you like it so far?