The River Bîc, which flows through the capital of Moldova is treated like an unloved step-child. The river itself and its immediate surroundings serve as a dumping site for all sorts of trash and polluted water. There are people working against this, for example the National Environment Center (http://www.environment.md/index.php/en) but more people (and decision makers) need to open their eyes to the issue at hand.
Despite flowing through the capital, the river also gets a fairly small amount of attention from scientists. Our impression is that they mostly focus on the rivers Prut and Dniestr. This is understandable since these rivers are much bigger but the amount of pollution in Bîc made us interested in working with it.
Therefor, during a two-month stay we, two students from the Royal Institute of Technology (Mikael Gillefalk and Felix Lindberg) are studying the river Bîc with focus on the sediments and the sediment transport. The river water is heavily polluted, with the biggest impact coming from activities in the city of Chișinău. We wanted to investigate how the pollution level in the sediments varies along a long stretch of the river. We also wanted to estimate how the sediment transport varies from day to day.
Sediment sampling
The sediment sampling was done in corporation with the State Hydrometeorological Service of Moldova. We started in the village Sipoteni, located about 60 km northwest of Chișinău, upstream Călărași and Strașeni, two cities that both affect the quality of the river water. This way we hoped to get a sample of sediments that wasn’t heavily affected by any human activity.
Felix working with the tube sampler. Here, the river is very small, more a creek than a river. You can also tell that that the water contains little amount of sediments (except for what is being stirred up be our work).
In total, we took samples from six points along the river Bîc. It was interesting to witness how it changes on its way from Sipoteni all the way to Gura Bîcului where it flows into the river Dniestr. On its way through Chișinău the river is sadly enough better described as a wastewater channel.
A lagoon suitable for sediment sampling, created by clay and trash.
Picture taken 20 meters from the river. We witnessed a few trolleys dumping different kinds of trash on the ground and into a hole, setting fire to the trash and driving away. Whatever is in the ashes will eventually be transported into the river with rainwater.
On our fourth expedition day we reached the point where Bîc flows into Dniestr. We’ve been told that when Bîc is really dirty you can see a black plume reaching into Dniestr. Not this day though.
Next to the water junction we had a short conversation with a man telling us that we should come back in the summer when he’s there fishing.
We sampled a few hundred meters upstream the outflow. This was the last of our six points.
A joint Swedish-Moldovan collaboration. Felix and Anatol hard at work. Mikael supervising.
Next week we will start analyzing the sediments for heavy metals, pesticides and nutrients. We look forward to seeing the results but need to keep in mind that sediment sampling can be tricky. The conditions can vary a lot, even within a small area. A complete picture of the sediment situation in Bîc is too much to hope for but we will lay a piece to the puzzle.
Sediment transport
Aside from our sediment sampling, we are also going three times per week to get water samples from the river. The water is later analyzed for suspended solids. The results tell us how the sediment transport varies.
On March 21st we were accompanied by Bianca Stumptner who documented our endeavors.
This is where we go to sample the water, taking microbus 171.
This tree, aside from looking nice, is actually helping us to determine the water level and the speed of the water.
We try to play it safe.
Measuring the water level.
Felix throws sticks into the water.
We have measured a distance of 7.2 meters between two trees. To get the speed of the water Mikael clocks the stick travelling this distance, a simple but quite accurate method.
A few weeks back, we measured the depth at a right angle to the river bank. Using those results together with the speed of the water we get an estimate of the river discharge at our sample station.
Nice pants.
When we get home we filter the samples through a home-built filtering device. Again, simple but working.
Making sure that there’s only one filter being used.
All devices using duct tape are by definition great devices.
Pouring water into the tube. Gravity is used to force the water through the filter.
We hope this post explains something of what we are doing. If you have any questions or wish to contact us, swing by our blog at moldocast com and drop us a line!
Picture showing the potential Bîc has to become a place for recreation for the inhabitants of Chișinău.
by Mikael GILLEFALK and Felix LINDBERG
photos by Mikael GILLEFALK, Felix LINDBERG, Bianca STUMPTNER
