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Featured Rethinking Evacuation Plans

  1. Sep 23, 2017 #1

    anorlunda

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    The Miami Herald posted this story. Built for bottleneck: Is Florida growing too fast to evacuate ...

    The article made a good point that I hadn't considered. A good evacuation plan does not require 10 million people to drive 600-1000 miles away. It means driving 10-20 miles inland to a shelter. In south Florida, 10-20 miles inland puts you in the Everglades or Big Cypress Swamp. Those are really bad places to build 10000 shelter buildings, holding 1000 people each.

    But then I thought of I75. It is an elevated roadway that crosses south Florida east-west. Suppose we told people to drive onto I75 and park on the highway. Just that one highway could park 250000 passenger cars (200 miles * 6 lanes * 5280 / 25 feet per car). Alligator Alley and the Florida Turnpike Could also be used.

    Perhaps Quonset-hut-like shelters could deploy to shelter the parked cars and to provide services. Maybe not. I'm short on details other than the following two thoughts.
    1. A good plan would make use of our highways and private vehicles as resources to help provide the shelter, rather than being part of the problems to overcome.
    2. The engineering challenges to make such a plan practical and affordable would be enormous. I suspect that many of my fellow engineers would relish being assigned to the project to think such a plan through, complete the design, then implement it.
     
    Last edited by a moderator: Sep 29, 2017
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  3. Sep 24, 2017 #2

    fresh_42

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    This would basically mean to build a 100 mile long tunnel with many junctions for its regular use, which must be wind shielded somehow. With it we would buy the severe danger of fires in the tunnel, which means separated escape tunnels would be needed and a complicated system of smoke handling. Again additional openings would follow, which are especially vulnerable to hurricanes: smoke out means hurricane in. And then there is the math. Let us assume four lanes on 150 km length with 5 m long cars, four persons in each car. That is roughly half a million people, and only if all behave according to the plans. I suspect that the chaos in case of an evacuation will be even higher than the one the tunnel is expected to avoid. And we would need a system to get rid of all the exhausts, which again results in additional openings. And then there is still the problem with the rising sea levels ...
     
  4. Sep 24, 2017 #3

    anorlunda

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    That may all be true. Engineering obstacles to overcome. But is more plausible to move 10 million people 600 miles in 24 hours? (Actually, the herald article said 21 million people, meaning evacuation of the entire state.)

    The worst case scenario is the conclusion that there is no safe way to evacuate, and we must not allow people to live there in the first place.
     
  5. Sep 24, 2017 #4

    fresh_42

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    An alternative would be buildings that can withstand hurricanes. I assume it would still be cheaper than the damage of say ten events. Of course there is still the sinkhole problem and I don't know how heavier buildings affect this problem. Another difficulty with the tunnel solution is eventually the pressure differences in a hurricane which directly affect partially closed buildings.
     
  6. Sep 25, 2017 #5

    scottdave

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    I think it is good to have brainstorming ideas such as this, in hope that a workable idea will arise.
     
  7. Sep 25, 2017 #6

    jack action

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    So nobody should live in the Caribbean? Countries should be completely erased, because no one should be allowed to live there?

    Don't you think this is an overreaction? There are way worst catastrophes happening in other (less developed) parts of the world, yet no one say such statements. These kind of things have happened for as long as humanity has existed and people adapt and live with it. Welcome to planet Earth.

    If one doesn't want to live there, fine. If one wants to share his/her concerns with others, fine. If one doesn't want to help them, fine by me as well. But if one wants to force someone to do something because he/she wants to calm his/her fears, or doesn't want to help if something goes wrong and doesn't want to feel the guilt that may come with it, I think nobody has that right.
     
  8. Sep 25, 2017 #7

    russ_watters

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    For perspective, Puerto Rico has a population of 3.4 million and last I heard a death toll of 10 from Maria. This pales in comparison to Katrina's death toll of 1800.

    We can build houses to withstand hurricanes. If they do it in in a charitably described "developing" territory, it isn't that hard. It just goes back to some of the same issues from the blackouts thread; getting people to care enough to put it into the building codes(see also: tornado alley). In Puerto Rico, that's not an issue: you know your home's construction will be tested, so you construct it accordingly.

    As you describe, evacuations themselves can be risky.

    So I agree; evacuations should be a laaaast resort.
     
  9. Sep 25, 2017 #8

    russ_watters

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    Something else regarding hurricane evacuations and this one specifically: max winds occur over a small region and hurricanes typically rapidly lose strength after making landfall. This storm evac was complicated by the fact that the storm ran parallel to the state and initially looked like it would run up through the middle, but that should not call for evacuating the whole state (we don't know where it will hit so evacuate everyone). There is no hurricane scenario that would call for evacuating the whole state.
     
    Last edited: Sep 25, 2017
  10. Sep 25, 2017 #9

    anorlunda

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    It's wrong to take a too narrow view of natural disasters. It is not just buildings and wind damage. For example, if too many people remain in flooded areas, dysentery, cholera, and typhoid can be the biggest killers in the long term. Public officials are forced to consider things like that when making evacuation decisions.

    It is also hard to make a general rule about the evacuation area. The flooding from Hurricane Harvey extended 150 miles (250 km) from the sea. Hurricane Irene's severe impacts extended more than 300 miles (500 km) from the sea.

    This if off topic. Clearly you think it's an overreaction. I think it's an overreaction. But I'm not so sure that society does. Society can use the same arguments about health care costs to discourage smokers, or to discourage people from living in risky areas. I consider that a result of the pressure of too much population. As population density increases, we are forced to entangle everyone's private business and the public's business. MYOB (Mind your own business) goes out the window. IMO, that is why the ACA is so offensive to many people; they don't want public involvement in their health, but the majority's will forces itself upon everyone.

    But please, lets' not let this thread get too far off topic. The subject is how to best accomplish evacuations, not whether to evacuate or whether to choose to live near the sea.

    Even if we think public officials should never order evacuations, we can still work to make evacuations as effective and affordable as possible when they are ordered. I think I can state the two principles of a good plan more clearly.
    1. Keep evacuation distances as short as possible.
    2. Make use of whatever you already have as a resource when possible.
    A good evacuation engineering team would demand requirements as step 1. Must we plan to evacuate 1 mile from the coast? or 5? or 20 miles (30 km)? or more? or in Europe, think of emergency evacuation of Italy or Greece? How far away, must the people move? 5km? or 1500 km? For how long? 1 day? 1 week? 1 month? How much time do we have to accomplish the evacuation? Those are basic requirement specifications.
     
  11. Sep 25, 2017 #10

    jack action

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    You are kind of answering your questions by suggesting too many options: For what type of disaster should we be prepared for? It becomes a probability problem. So, no matter for what level of disaster you will be prepared for, there is always a chance that one bigger will happen.

    We lived something like that in 98 around here with an ice storm. One of the big problem was that in the area that was hit hard (the «black triangle»), there was a main electrical line that was destroyed, putting the most populous part of the province into darkness. They quickly add another one after the storm, such that «it would never happen again».

    How can anyone prepare for that? IIRC, it is considered an event that happens once every 100 years. Nobody knows where it will hit exactly. When do «prevention» becomes «waste of money»?

    Once an area is flooded, it is relatively «easy» to evacuate only the people concerned, which is kind of the traditional scenario we are used to. So it really is just a «buildings and wind damage» problem.

    What we are discussing here is evacuating an entire region - even an entire state - «just in case», because we don't know IF something will happen and WHERE it will happen.

    If I may add something positive for the «evacuation plan» concept is the addition of small independent roads to let the emergency vehicles and supplies go in & out of the urban areas, such that it solves the problem mentioned in the article you linked:
     
  12. Sep 28, 2017 #11
    We gave all these issues careful consideration when we moved back to the south a few years ago. Our household basically decided that the only way we would locate south of I-10 was to evacuate 72-96 hours ahead of any possible hurricane strike on our location. It's not enough to beat the storm, we wanted to be well ahead of all the other evacuees. Even with a solid evacuation plan, some family members were not comfortable living further south than Gainesville, FL. My wife interviewed for a job there and there are plenty of routes out not only to safety, but to locations not flooded with other evacuees creating a need for massive governmental assistance.

    I grew up in New Orleans which (in spite of limited population) can be an evacuation nightmare due to limitations on the evacuation routes.

    We're in the 8th year of a 10 year fisheries study in SW LA. We intentionally scheduled it for sample collection each year just before hurricane season, because we wanted to ensure a continuous annual sampling without needing an asterisk or two for sampling interrupted by hurricanes. The fishing is so good down there that my brother just bought a beach house in SW LA and a second property where he plans to build a second home. He understands that such accommodations are temporary, with the only question of when (NOT IF) a hurricane will destroy the homes and possibly even the very land they are built on. It goes without saying that he has all the evacuation routes well rehearsed with multiple contingencies and back up plans. Fortunately, this area is sparsely populated.

    Likewise, we always have our evacuation routes planned when we visit the Gulf coast during hurricane season. Our family ended up settling north of I-10, which (except for parts of New Orleans) greatly reduces the likelihood of needing to evacuate and also greatly increases the available routes relative to the number of people likely to be on them.

    But for those who have actually been down here in the aftermath of a storm, a lot of the ideas above are just silly. It is so hot and humid down here in the summer, that sheltering in a motor vehicle for more than 24 hours is untenable. Being trapped on a bridge in a motor vehicle with hundreds of other evacuees is about the last place on earth I want to be in the summer heat. Even sheltering in place in a residence for more than about a week requires careful planning and coordination if electricity and water and sewer services are interrupted. The shelter in place plans I recommend for friends and family includes 2-4 weeks of food and water, plans for known prescription medications for 4 weeks, plans to not have functioning toilets, and plans for possible dosages of anticipated medications for the most common disease outbreaks in these situations. We do not want to depend on government to solve a disaster caused by a hurricane. Hurricanes are foreseeable events. Steps of household planning are straightforward.
     
  13. Sep 28, 2017 #12

    Ygggdrasil

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    While this is correct, many more deaths are expected to result from the aftermath of the storm (which knocked out 80% of the territory's power lines), where some areas are expected to be without electricity for 6-8 months.

    https://www.vox.com/science-and-hea...tarian-disaster-electricty-fuel-flights-facts

    The fact that an order of magnitude more deaths will come in the aftermath of the storm points to the huge flaw in the OP's plan of using highways as areas to shelter people during disasters. Parking hundreds of thousands of cars on main travel routes will impede emergency workers from rescuing those in need and slow efforts to repair critical infrastructure and deliver essential supplies in the aftermath of the storm.
     
  14. Sep 28, 2017 #13

    anorlunda

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    Evacuation might be wildly unpopular. Libertarians might hate that the governor has authority to order mandatory evacuation. Nevertheless, that's what we have. Acting constructively means doing our best to make evacuation plans that work rather than fail.

    (I'm not remote from this problem. I have a friend who refused to evacuate from his boat in the Keys. His body was found in the rubble. It appears that he made it to shore, but then died before walking 4 meters away. Of 450 boats in the harbor in Marathon, only 52 survived. Yet 100% of the boats that evacuated to the mangrove forest 1 km away survived. Likewise 100% of those who evacuated to the mangroves in the Everglades survived. Boat-based strategies differ from land-based strategies, but those survivors moved a minimal distance away and they made use of resources they already had.)

    That's true. In fact, the Miami Herald article linked in the OP said that authorities refused to close southbound lanes to allow for emergency vehicles. That cut the evacuation capacity of highways in half. That is part of what triggered the article's premise that S. Florida's evacuation plans are inadequate.

    When the governor orders mandatory evacuation, you must go. So you may not be allowed to use your shelter in place plans.

    Personal vehicles offer imperfect shelter from wind and rain. They also provide AC as long as we keep them fueled. That is what I meant by using resources that you already have. The massive engineering challenges include providing food, water, fuel, and sanitation to evacuees. Even if they evacuate to buildings rather than cars, those services must be provided anyhow.

    Also, don't neglect the devastation of The Everglades and Big Cyprus Swamp if we are forced to build 10000 shelter buildings and parking lots there or alternatively to build enough highway lanes (including rest stops and gas stations) to make long-distance evacuations practical.

    Sadly, the aftermath problem is playing out right now in Puerto Rico and Caribbean Islands. They are not 100% directly comparable to South Florida, but surely painful lessons learned there should be applied to the mainland.
     
  15. Sep 28, 2017 #14
    If a residence is under a serious enough threat for a mandatory evac, most of my family are inclined to be out of dodge long before the order comes down. Waiting for the order is begging to be stuck in the traffic jam of poorly prepared evacuees.

    "Shelter in place" arrangements are for near misses and lighter hits that do not warrant evacuation. Still, friends and family with generations of hurricane experience regard preparations for 2-4 weeks without reliable power, water, new food, fuel, or medical assistance as a minimum preparation for sheltering in place. Infrastructure and service disruptions can last a long time even in areas not under sufficient threat for mandatory evacuations.
     
  16. Sep 28, 2017 #15

    I like Serena

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    I may be missing something here, but how about developing buildings to be hurricane proof and put that in the building codes?
    Then evacuation can consist of going to the nearest hurricane proof building if your own building is not hurricane proof yet.
    As for the flooding, how about developing and building mechanisms that can handle the excess water?
    This could be expensive, but whenever something is in place in a particular region, that region can becomes an evacuation point.
    And over time, it can cover more of Florida.
    As for the power lines that tend to go down, how about putting them under ground?
    Am I missing something? Is there a reason not do to it like this?
     
  17. Sep 28, 2017 #16

    Choppy

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    Perhaps I'm misunderstanding something. I would echo a concern brought up earlier that intentionally choking off a major artery is a recipe for a disaster in and of itself. People can survive in their vehicles for several hours, but before long they need to relieve themselves, drink, eat, and sleep, wash, etc. On top of that, there is an issue of coordination, and the fact that in an emergency other roads make be taken out, severely limiting access/escape. This just sounds like a nightmare scenario to me.

    I suspect a lot of this comes down to cost. A hurricane-proof house is more expensive than one that isn't. And despite the damage inflicted by the recent events, the relative probability of any given house being destroyed by a hurricane is probably still very small. So for the average homeowner or home builder, the added cost of "hurricane proofing" a house may not be worth the risk.

    And remember, you can have a hurricane proof house, but you also need hurricane proof infrastructure too. Your fine house may not seem all the great with the water cut off, or no electricity, etc. Burying those cables costs money. In the next election, one guy will run on a platform that raises taxes to pay for the extra cost. How viable will that platform be if people aren't immediately worried about hurricanes during the election?
     
  18. Sep 28, 2017 #17

    StatGuy2000

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    One of the things that always puzzles me is why people choose to move to a location which consistently experience hurricanes year upon year. Obviously people who are born and raised in those regions, such as those living in the Caribbean, have no choice but to live there (unless economic or other conditions force these to move), similar to people who live in countries like Japan (a nation that experiences earthquakes, live volcanoes, tsunamis, and typhoons). But I'm thinking more specifically of people who specifically move to areas like Florida from further north in the US.
     
  19. Sep 28, 2017 #18

    Dr Transport

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    ever been to the Caribbean, the islands are rocks, burying power lines would nearly be impossible....
     
  20. Sep 29, 2017 #19

    Choppy

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    Sometimes you're just trading one type of risk for another. For example, you could ask the same thing of people who knowingly risk the dangers of winter in northern areas (falling on ice - a major issue for elderly people, increased traffic accidents from freezing rain, heart attacks from shovelling snow, etc.). I don't know what the relative risks are, and I suspect the detailed evaluations of such things are not high on people's list of priorities when considering a move.

    If one does choose to live in a location that is more prone to natural disasters, for the most part, the risk of death or massive property damage is still quite low compared to other risks. This map suggests that the relative risk of a natural disaster across the US varies by roughly a factor of 4. But it doesn't give any absolute probabilities. Maybe someone else can dig up some actual numbers, but I strongly suspect that for most people the absolute probabilities (or at least the perception of them) is low enough that it's noise. These aren't actual numbers, but my point is that the difference between 0.000001 and 0.000004 is probably not as important to most people as the fact that they get to live near a beach, or that they'll have a job.
     
  21. Sep 29, 2017 #20

    I like Serena

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    Suppose a new residential area was built with only houses that have the new label 'hurricane proof', endorsed by the government, and exempting them from evacuation.
    With a mechanism in place to handle flooding, easing building requirements for the houses.
    With underground power lines.
    And with emergency power for the whole area.

    I imagine that people that are currently deterred from moving to Florida would happily buy these houses.
    Many people would want to have such a house that is deemed safe, and that they won't be chased from no matter what happens.
    Prices might even soar due to high demand...
    As for elections, suppose a candidate promotes and supports something like this... it seems to me that it would speak to the people.

    Every place would need a solution that fits the circumstances.
    In cases like this a local emergency aggregate might be a better solution, perhaps together with an instruction (or power limit per house) to reduce power usage to a minimum.
    Or we might just accept that power could be out for a while, which should be okay since it's usually not life threatening - just inconvenient.
     
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