3 ms·

Yeah I dunno if I like the false choice between "evacuate incompetently" and "don't evacuate at all." Could there maybe be a third option of evacuating only the

Yeah I dunno if I like the false choice between "evacuate incompetently" and "don't evacuate at all." Could there maybe be a third option of evacuating only the relevant areas (low-lying ones near the bayous), safely and efficiently, via a well-thought-out plan?

sohkamyung 9y ago
If I read the article correctly, most of the flooding is due to heavy rains, not storm surge. Even in Singapore, predicting which areas will be flooded due to heavy rains isn't easy, judging from the number of local reports of floods after heavy rains. This will make it difficult to judge which areas to evacuate. This is the relevant part of the article: "Attempting to evacuate areas that might be affected by localized flooding because of rainfall is an entirely different problem from evacuating areas in danger of flooding by storm surge, the rise in seawater level caused by a storm’s winds pushing water onshore. We can predict with reasonable accuracy what areas will be flooded by storm surge based on the forecast and elevations. But flooding from rainfall is highly unpredictable and variable based on the dynamics of each particular rain event. Rarely will we know days in advance which areas will be flooded."
- rdiddly 9y ago
  Yeah but, hydrologists have a joke: What's the first law of hydrology? Water runs downhill. Which is funny when you're a PhD accustomed to wrangling ridiculously complex multidimensional partial differential equations from fluid dynamics, to say the same thing. But I suppose what ruins any ability to rely on "the first law of hydrology" here is the fact that the whole area is so flat, and so low, and so paved.
  - rdiddly 9y ago
    https://qz.com/1064364/hurricane-harvey-houstons-flooding-made-worse-by-unchecked-urban-development-and-wetland-destruction/ https://qz.com/1064364/hurricane-harvey-houstons-flooding-ma...

sohkamyung 9y ago

If I read the article correctly, most of the flooding is due to heavy rains, not storm surge. Even in Singapore, predicting which areas will be flooded due to heavy rains isn't easy, judging from the number of local reports of floods after heavy rains. This will make it difficult to judge which areas to evacuate. This is the relevant part of the article: "Attempting to evacuate areas that might be affected by localized flooding because of rainfall is an entirely different problem from evacuating areas in danger of flooding by storm surge, the rise in seawater level caused by a storm’s winds pushing water onshore. We can predict with reasonable accuracy what areas will be flooded by storm surge based on the forecast and elevations. But flooding from rainfall is highly unpredictable and variable based on the dynamics of each particular rain event. Rarely will we know days in advance which areas will be flooded."

rdiddly 9y ago
Yeah but, hydrologists have a joke: What's the first law of hydrology? Water runs downhill. Which is funny when you're a PhD accustomed to wrangling ridiculously complex multidimensional partial differential equations from fluid dynamics, to say the same thing. But I suppose what ruins any ability to rely on "the first law of hydrology" here is the fact that the whole area is so flat, and so low, and so paved.
- rdiddly 9y ago
  https://qz.com/1064364/hurricane-harvey-houstons-flooding-made-worse-by-unchecked-urban-development-and-wetland-destruction/ https://qz.com/1064364/hurricane-harvey-houstons-flooding-ma...