Watch this 14-minute information-packed engineering video, presented by Grady Hillhouse of the Practical Engineering YouTube channel, and you might agree with “why it’s so difficult, and some might even say impossible, to control rivers.”
“Because any change you make upsets the dynamic equilibrium between water and sediment. And even if you armor the areas subject to erosion and continually dredge out the areas subject to deposition, there’s always a bigger flood around the corner ready to unravel it all over again. So many human activities disrupt the natural equilibrium of streams and rivers, causing them to either erode or aggrade, or both, and often the impacts extend far upstream or downstream.”
“It’s not just dams, bridges, and channel realignment projects either. We build levees and revetments, dredge channels deeper, mine gravel from banks, clear cut watersheds, and more. Historically we haven’t fully grasped the impacts those activities will have on the river in 10, 50, or 100 years.”
Rivers are wild and ever-changing, and the unintended consequences of human intervention end up being wild and ever-changing, too. Hillhouse demonstrates this on Emriver stream tables, geomorphological river science simulation models that were first built in the 1980s by Emriver’s late founder, Steve Gough.
“At the time, he was working with the state of Missouri trying to teach miners, loggers, and farmers about the impacts they could have on rivers by removing sediment or straightening channels. These people who had observed the behavior of rivers their entire lives were understandably reluctant to accept new ideas. But, seeing a model that could convey the complicated processes and responses of rivers was often enough to convince those landowners to be better stewards of the environment.”
The video above is a follow up to Practical Engineering’s Why Rivers Move, “the basics of fluvial geomorphology (the science behind the shape of rivers).” A sponsored message begins at 13m45s.
Watch these videos next:
• Why Do Rivers Curve? – MinuteEarth
• Earth’s Hydrosphere and Geosphere + Weathering and Erosion
• Why are beavers and their super wild, messy wetlands essential?
• Erosion demonstration: Comparing grass, dead leaves, and soil
• What is groundwater?
• What are the secrets to designing great hiking trails?
• Mangrove Forest: Coastal Erosion Mitigation
• Why are mangrove trees so important?
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