When Katrina made landfall, it may have been a Cat 3 but by the time it got to New Orleans, it was more likely a strong Cat 2.
They slow down fast when they hit land. The friction from land masses just chew up the energy of the storm.
But the damage wasn't caused by being Cat 2, Cat 3, Cat 4.
It came in two parts.
Part 1 was the storm surge - which is higher when the pressure is lower (aka stronger storm), but also the size of the hurricane matters. A big storm can become less intense but still be big in size. That destroyed Plaquemines Parish, St. Bernard Parish, and New Orleans East.
Part 2 was those stupid walls on the drainage canals that were not strong enough, nor deep enough, nor on strong enough ground/dirt/earth for the foundation. Those broke or otherwise failed after the storm due to poor construction.
The drainage canals are full of water all the time because the pumps work day and night to pump out storm water from ordinary rain storms and so forth. Those were the source of the flooding for the most densely populated areas, the expensive flooding, from Lakeview to Mid-City. |
