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I’m teaching intro geology for engineers this term. They often grumble “But whyyyyyy???”
This.
This is why.
Details: timesofindia.indiatimes.com/city/raipur/ri…
(Thank you @sandygrains for helping me navigate Indian geoscience news coverage!)
This.
This is why.
Details: timesofindia.indiatimes.com/city/raipur/ri…
(Thank you @sandygrains for helping me navigate Indian geoscience news coverage!)
Q: How does a river just change where it’s going?!?
A: Rivers are inherently dynamic systems. They’re ALWAYS changing course unless you’ve heavily engineered structures to lock them in position (which has a LOT of secondary impacts).
A: Rivers are inherently dynamic systems. They’re ALWAYS changing course unless you’ve heavily engineered structures to lock them in position (which has a LOT of secondary impacts).
Most common reasons for abrupt changes in a river are due to changing discharge &/or sediment load.
Discharge is how much water is flowing in the river.
Sediment load is how much & what type of sediments are carried, including how it’s transported (& if it’s eroded/deposited).
Discharge is how much water is flowing in the river.
Sediment load is how much & what type of sediments are carried, including how it’s transported (& if it’s eroded/deposited).
Discharge & sediment load change seasonally: watch your local stream go from a mostly-clear trickle in the dry season to a raging muddy torrent after heavy rains.
But it also changes from engineering (deliberate or accidental), land use, landslides, & more within the watershed.
But it also changes from engineering (deliberate or accidental), land use, landslides, & more within the watershed.
What happened here? A few days of heavy rain increased discharge. When the river shifted, it found the mine.
Big hole in the ground + overly-full river = epic waterfall
Soft sediments + powerful flow = rapid erosion
Big hole in the ground + overly-full river = epic waterfall
Soft sediments + powerful flow = rapid erosion
Q: What happens now?
A: Depends how much the coal mine is worth & what local environmental regulations are, but likely a variant of “Wait for low discharge, reroute the river, & pump until it’s dry-ish.”
A: Depends how much the coal mine is worth & what local environmental regulations are, but likely a variant of “Wait for low discharge, reroute the river, & pump until it’s dry-ish.”
The real question is:
Did someone fuck up?
How predictable was this event? What monitoring was in place? Was it part of the risk assessments? Why or why not? How rare was this rainfall event? How dynamic is the history of this particular river? Who made what decisions & why?
Did someone fuck up?
How predictable was this event? What monitoring was in place? Was it part of the risk assessments? Why or why not? How rare was this rainfall event? How dynamic is the history of this particular river? Who made what decisions & why?
In Canada, engineers sign off on everything that is created or destroyed.
Some of my students will specialize in geological engineering, but most of them need to learn enough to understand when & how to bring in experts, and how to use those consultants to make good decisions.
Some of my students will specialize in geological engineering, but most of them need to learn enough to understand when & how to bring in experts, and how to use those consultants to make good decisions.
Our course has explicit learning goals about rock types, soil hazards, geologic processes, blah.
But the real objective?
Keeping my students from accidentally killing someone someday.
They’ll get sued. They’ll make mistakes. It happens. But I don’t want deaths on their hands.
But the real objective?
Keeping my students from accidentally killing someone someday.
They’ll get sued. They’ll make mistakes. It happens. But I don’t want deaths on their hands.
I’m also teaching the geoengineering capstone before we send them out into the world.
We don’t talk geo AT ALL.
It’s entirely how to be ethical professionals hammering home the importance of getting the right data, taking responsibility for decisions, & diligent documentation.
We don’t talk geo AT ALL.
It’s entirely how to be ethical professionals hammering home the importance of getting the right data, taking responsibility for decisions, & diligent documentation.
