Erosion in Rivers
Soil erosion in a classroom demonstration and along the coast in Positano, Italy.Copyright 2012 Eduardo Suescun (left) and Sophia Mercurio (right), Polytechnic Institute of NYU
Students learn about water erosion through an experimental process in which small-scale buildings are placed along a simulated riverbank to experience a range of flooding conditions. They learn how soil conditions are important to the stability or failure of civil engineering projects and how a river's turns and bends (curvature, sinuosity) make a difference in the likelihood of erosion. They make model buildings either with a 3D printer or with LEGO® pieces and then see how their designs and riverbank placements are impacted by slow (laminar) and fast (turbulent) water flow over the soil. Students make predictions, observations and conclusions about the stability of their model houses, and develop ideas for how to mitigate damage in civil engineering projects.
Civil and geotechnical engineers carefully investigate the soil in the surrounding area where structures are going to be built so they can best plan for the future safety of the structures. Civil engineering projects such as skyscrapers, bridges and highways require solid foundations, and preferably placement in areas that are not susceptible to erosion. Engineers must also be knowledgeable of the types of construction materials that can resist water erosion. Engineering solutions to erosion problems may include the extension of foundation systems, installation of vegetation, and modifying the water flow or direction. The erosion table demonstration in this activity shows students how water can move soil and how erosion can affect buildings.
After completing this activity, students should be able to:
- Explain the water erosion phenomenon.
- Identify the main causes of erosion along riversides.
- Compare the effects of fast (turbulent) flow versus slow (laminar) flow.
- Identify solutions that engineers design to mitigate water erosion.