Group 1 consists of 5 Savonia students: Ilkka Summanen (FIN), 3rd year environmental engineering student, Tobias Lickert (GER), Lisa Bourdier (FR), Tristan Faure (FR) and Audrey Saintfélix (FR), all mechanical engineering students. Ilkka has some experience and courses on measurements and fieldwork, the rest of the group doesn’t have the same experience. While the majority of our team does not specialize in environmental studies, we share a common passion and curiosity for the natural world, which led us to embark on this journey to Finland. This class is a great opportunity for exchange students to explore the intricate relationship between engineering and the environment while immersing ourselves in Finnish landscapes. And for Ilkka this course provides field experience, and a multilingual working environment.
On Tuesday September 19th 2023, our international team discovered the lake Pieni-Valkeinen, located near the Päiväranta neighborhood in Kuopio, Finland. Our first task was to review the catchment area of the lake and measure the discharge of input and output streams using current meter.
Review of the catchment area and observations of the environment
Expedition date: 19.09.2023
Weather: sunny + cloudy
Atmosphere temperature: 9°C
Figure 1 : Catchment area in blue (Value-tool)
Around the lake we can find a big part of nature, the Puijo park, and a small part is composed of constructions: inhabitants, car park and recreation area (near to the input stream).
We guessed this lake is used for recreation activities like swimming and fishing (developed beach for inhabitants). We could observe people enjoying the fresh air and dog toys forgotten around the lake leads us to understand it is the perfect place to walk your dog. Some houses have their own access to the lake.
We noticed that there is a new construction near to the output stream. It seems to be an individual home.
Figure 2 : construction site near the lake
Except this, nothing new was noted.
Input stream: we can find two input streams.
Main input stream: not deep, and with a very small flow. Main input stream is located near the car park and the recreation area. We saw a bike in the water.
Incoming stream location : 62° 55.769 N 027° 39.526 E
Second input stream: very small flow too. We observed pound areas so we deducted that the water doesn’t directly go to the lake.
We guess that the other input stream could be bigger on a rainy day.
Figure 3 : bike in input stream ( possible source of pollution )
Secondary small stream observed location: 62° 55.599 N 027° 39.533 E
Around the lake with saw a lot of small pounds, created by some stream from the hill or maybe due to rainy days. We noticed that forest is growing, we saw some swamps too.
Pond area and third incoming stream observed: 62° 55.685 N 027° 39.544 E
Output stream:
We saw only one visual output stream. The flow is quite slow too and not deep at the output lake. But the flow is bigger after this cause of drop in altitude to go to the next lake.
Outgoing stream from pieni to iso Valkeinen : 62° 55.728 N 027° 39.923 E
We talked about possibilities of having underwater sources as we observed that the input stream seems bigger than the input stream.
Potential sources of pollution : -Human pollution: bike, plastic waste, traffic, small scale wood combustion …
-Dead leaves of vegetation
-Deteriorations of construction
To conclude about this expedition, we guess that this lake could be in good lake condition but not great, cause of human activity near this one. It can be used as recreation time but not for drinking. There are no industries near the lake, and no boat activities.
Figure 3 Points of interest around Pieni-Valkeinen
EXERCISE 3: DISCHARGE MEASUREMENT USING CURRENT METER
For this exercise, we had to make measurements from the inlet and outlet channel of the lake.
Points of streams measurements :
Output stream measurement : 62° 55.727 N 027° 39.780 E
Input stream measurement : 62° 55.783 N 027° 39.490 E
The first thing to do was to assemble the measurement device:
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| Figure 4 : Measurement device |
After that, we could start to take measures. We need to find a spot in the outlet and inlet channel, which is deep enough, has enough stream and is not too small.
To know that we could measure the channel with a measuring tape to know the size.
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| Figure 5 : Measuring the outlet channel |
We also use the measuring tape to know the position of the device in the channel.
When we have a good spot, we can start to measure the propeller revolution per second. For the outlet channel we were able to make 2 measurements, 1 at 10 cm of the border and one at 25. We try to make a third one, but a bump deflects the flow.
And for the inlet channel, the channel was very tight and it was very difficult to take several measurements.
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| Figure 6 : Measurement of the inlet channel |
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| Figure 7: Location of inflow and outflow measurements |
With those measurements, we can now calculate the velocity of different channels. We have this equation V=k×n+D. With k the hydraulic pitch of the propeller (m), n the propeller revolution per second and D the characteristic of the current meter. We already know that D=0.005 and k=0.2591m.
And we also need to have the discharge with this equation Q=V×A. With V the velocity and A the area of the subsection
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| Figure 8 : Example of subsection |
For the first area we can think that is a square triangle and for the second one that the area is a rectangle.
Figure 9: Mesurement results
Because of the small depts it was difficult to feel velocity of stream. We can notice that the inlet discharge is less important than the outlet one. We concluded that the two incoming streams we found were not the only ones. We guess that there are some underground incoming streams that we can’t see. And it could be the same for the output stream.
However, our results may be distorted by the difficulties to find a good spot to make out experiments (no dept, no flows, …). Despite this, our results are not inconsistent and we can conclude that the possibility of underground incoming sources are very high.
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