Rivers, River, Rivers!

Apologies for no water and health post yesterday, I didn’t have time. But don’t fret, it is coming!

Today’s activity was down by the river and measuring discharge via a plethora of methods. The aim of the day is to compare and contrast the various methods of discharge measurements and estimation. The first method is the highly scientific method of the surface-float velocity profiling. This involves using a scientifically calibrated orange to measure velocity of the river by timing how long it takes to float from one point to another. The next method utilized current meters to directly measure velocity from a range of points across the river channel, allowing for a velocity profile to be produced. The following method is quantifying discharge using salt dilution. This involves calibrating river water into a saline solution. The saline ‘slug’ is then injected into the river and ten stream width downstream a student stands with an aqua probe measuring the changes in salinity. The slug of salt water will then show up on the readings as a spike.

The final method of the day was the slope area method for estimating discharge. This method involves students using levelling gear to measure the channel profile and slope. The sediment of the river bed is also sorted so that a roughness value can be calculated. This method is often tricky to get right (not for our students of course) and involves inputting data into an equation which seems to turn people off the method (which I was in charge of teaching).

It was a really great day, the sun was beaming down on us and the river was nice and cool. The students must be commended for their effort and hard work through the day. As the with most fluvial work it was an intense day, hardly time to stop for lunch! By the end of the day and the coach journey back Ray Ward and I deduced we had about an 80% rate of students sleeping. Sign of a good hard days work!

Tonight the students are going to be putting themselves into groups for their individual group projects. Projects can be done on a range of topics utilizing the techniques they have learnt in the previous days. I’m looking forward to seeing some interesting projects!

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