• Orientation and terrain structures along the river: This experiment introduces the pupils into the location of the river they are supposed to investigate.
• Flow patterns, temperature, algal growth and oxygen: Physical parameters like water depth, stream velocity, temperature and dissolved oxygen provide the opportunity to elucidate interrelations between flow patterns, algae growth and oxygen.
• Vegetation as a natural water filter: Plants are an important element in river ecosystems. Vegetation stabilizes the banks, and plays an important role in the self-purification of the stream water. In this experiment the pupils will aim for assessing the impacts of different types of river vegetation on the optical quality (transparency, colour) of the water.
• Looking on eutrophication processes: Water pollution is not always visible, and many poisonous substances do neither smell nor taste. We will therefore not be able to determine the water quality with our senses alone. Some hazardous substances like pesticide residues are so difficult to detect, that sometimes even highly sophisticated analytical laboratories are struggling in determining the water quality of a river. Also, new pollutants are discovered as the detection methods are developed. This experiment will introduce the pupils to a simple method to determine nitrate levels and link them to the issue of human impact like eutrophication and acidification.
• What happens after the waste water treatment plant: Does a water toilet also look nice to the fishes in a river? How much of the pollution is getting decomposed and removed in the waste water treatment plant? What happens with the effluent in the river? This experiment will provide answers to those questions and will reflect on the current way to deal with toilet wastes. Pupils will follow the effluent of a waste water treatment plant and look what happens with the river section below this place.