hey all now that we've gone through the basics of hurricane formation categories characteristics and talked about the 1900 hurricane I just wanted to end the hurricane related stuff talking about more present day issues and where we go from here so some of you guys may recognize uh literally this spot okay right along elvaston Island and the seaw wall and you can see kind of what the coastline looks like today remember the seaw wall has been in place along portions of the island since the early 1900s after the hurricane took place and we can see that there's been Beach restoration and things like that through the galison park board and the Army Corps of Engineers that helps to replenish the beach because it gets eroded through natural physical processes over time and so we can see that development of the island definitely did not stop it has continued and you have things like Pleasure Pier and lots of other things things behind the seaw wall and then other tourist areas as well that aren't just behind the seaw wall although getting outside from the seaw wall you have more private land ownership and things like that and a little bit less commercial development in some of those regions and sometimes if you get down there on the right day you get the wind currents that reverse a little bit and they bring in water more from the south and you get nice pretty blue water most of the time the winds kind of dominate out of the Northeast or have a more easterly Direction and it carries a lot of sediment from the Louisiana coast the Mississippi River and other things down along the coast but you can occasionally get the winds that reverse and you get pretty pictures like this with nice clear blue water but you can see there's definitely still development there and the island is still susceptible to potential hurricanes that could hit and if you look at the end of the seaw wall and get down to the very end the portion that was built so these top two pictures up here these two pictures show the end of the seaw wall okay and then as you get Southwest from there you're no longer in an area protected by that 17t seaw wall and so the picture on the bottom here shows more what that landscape looks like and you can see a lot of the homes are raised a lot of the newer homes are raised even higher than some of the older homes and that's all done because the understanding of storm surge they could impact these areas and what could happen during a tropical storm or hurricane so trying to create things that are more resilient to that type of storm surge damage that we saw in 1900 and some subsequent hurricanes since then so when we look at the actual impacts of a potential hurricane this is a one in 10 year event or a 10% chance of happening any given year related to storm surge and so you can see some areas that are levied off to protect infrastructure like over here okay in Texas City and the oil and gas infrastructure and petrochemical Industry those are protected by category well at least the Texas City one is protected by a category 3 storm Levy and Ike was a strong two was almost right up to the top of that and then you can see that the risk of flooding right behind the seaw wall right on the island itself right if you look in behind here there's very low risk from a relatively small hurricane however as you get into other areas like in bivar and like the West End of the island these areas all have a chance of flooding from storm surge because they are not currently protected by a seaw wall and so we can see the impacts from something like Ike which again was a strong category two and what that means for today's landscape looking at before and after pictures of a little bit more more developed areas and more natural areas okay so we know the island itself is a Barrier island is subject to overwash from storm surge and things like that that can cause damage and what happens to more populated areas again especially populated areas that are not protected by the seaw wall they are subject to Major Devastation and this is why going forward when you see homes built or rebuilt after these storms they are increased in elevation in terms of the base elev Elation of the house on peers and things and many of them are above 20 ft base elevation in terms of How High they're raised the reason why many of them are raised to at least that height is because some modeling that's been done by the Army Corps and the National Oceanic Atmospheric Administration looking at how high storm tide could get now at this point this is a few years old and the estimates now have storm surge at galison Island they could get up to 23 ft so it should actually be more of this orange color right in here but when this was done a few years ago they had the heights right in here around 20 to 22 feet okay and now we know that it could get up to 23 feet and that would be a few feet over the seaw wall if you had the worst case scenario Category 5 hurricane hit during high tide okay and so if you had an orientation of a cat 5 like the 1900s storm blowing all that water in right here in this direction that could cause over topping the seaw wall and then you would also have other areas that were obviously devastated if the seaw wall were over topped as well so when we look at the likelihood or the probability of different storms hitting different parts of the US you can see some places that stick out okay South Florida can be hit by storms that wind up going in over the gulf or move up the east coast of Florida the Barry Island systems and the Outer Banks of North Carolina they stick out a little bit further than some other areas in this region okay and so they have a relatively High return period meaning one in five one in six one in seven years okay and that's just a fraction in terms of probability that we'll learn more about during flooding but all these numbers are as the denominator of a fraction so for example where we have the Houston Galveston area right okay within 50 kn miles of these areas there's a one in nine chance see the number Nine's there okay so for the Houston Galvis scen area there's a one in nine chance every single year that it could be hit by a hurricane okay these other areas which you see like the Outer Banks of North Carolina over in here again where you see this five there's a one in five chance a 20% chance that that area could be hit every year okay so some areas it's more common some less and this is based on looking at historical documentation over 150 years of data and it just so happens that two major hurricanes that hit us in this region Ike in 2008 and Harvey in 2017 were exactly nine years apart it doesn't always work out to be that nice in terms of the averages okay but it just so happens that our 9-year return period or one in nine chance along the Houston galdon area Okay happening to be the same amount of time that passed between Ike and Harvey okay I also want to point out just real quick that a good portion of the Hurricanes that hit the us that are intense category four or five have hit either Florida or Texas and part of that is because When Storms get in the Gulf Texas has the largest Coastline along the gulf okay outside of um Florida which also has a pretty big Coast line and the storms that also don't get into the Gulf can wind up working their way this way if they're going to hit the US and so Florida can catch them on the east side or the west side in terms of how they're impacted okay so the bulk of our major hurricanes have impacted Florida or Texas and so when we look at our hurricane Hazard areas the reddest areas tend to be the highest risk okay in terms of the probability every year of being hit you'll also notice Puerto Rico here in the inset map and then the darker blue area is a little higher probability the lighter blue areas is a little bit less in terms of their statistical likelihood of actually being impacted by Hurricane Forest storms this also relates to something called a hazard risk score so you can see all the areas along the gulf and part of the East Coast that could be impacted by these hazards but you can also pick out other hazards that can impact the landscape as well so you'll notice in the center part of the US right in here you have flood Hazard because the Mississippi River flows through this area Okay out here you have wildfires landslides these kinds of things in here you have some flooding but also tornadoes and things like that that we've talked about so really where you live depends on the kind of Hazard that you could be impacted by and the hazard is pretty high along the Gulf Coast because of how often we could be impacted by hurricanes and tropical storms and flood events and things of that nature so let's talk a little bit about hurricane Harvey and how that has influenced where we're at today hurricane Harvey took place again during Peak hurricane season in 2017 okay and there's a little video of Harvey making landfall down there if you'd like to check it out in the PDF but this is the path that Harvey took okay and so it exploded into a major hurricane came relatively quickly you'll notice right down here right right in here it was actually a tropical storm in category 1 hurricane before it exploded very quickly into a two three and ultimately made landfall right in here as a category 4 okay so this takes kind of an interesting pattern because what happened is there there's a big high pressure system over here Texas and there's another one over here okay and so remember we have clockwise flow around our High Press systems in the Northern Hemisphere okay and so what happened is this low pressure system gets pushed into the state of Texas but it can't push the high pressure system out of the way so it gets stuck right here okay remember high pressure systems steer low pressure systems not the other way around and so it gets pushed into Texas and then it gets kicked back out to the gulf this way and then it takes this zigzag pattern before it finally takes the more typical pattern makes landfall again and then gets caught up in the Westerly winds so why am I spending some time on this I'm spending time on this because while it's all in here while the eye of the storm is all in here right it's pulling rainbands into the Houston area and E Texas okay and so the way this storm sat there and got stuck between two High Press systems that's what caused it to be as bad as it was typically it'll make landfall so typically what would happen is it would have made landfall and then it would have continued like this like you see just east of there but because it got stuck and then it moved in and moved back out it sat there for four or five days instead of making its way through in a day or two which caused catastrophic flooding and so you may not know this but the National Weather Service actually had to redesign their precipitation color scheme because there was so much rainfall that fell during Hurricane Harvey that their existing color scheme did not work by itself okay and you can see that there was over 60 Ines of rain that fell during the storm so over 10 Ines above what the annual average is for the Houston area remember we said that's about 50 inches of rainfall annually and in this few day period they got over 60 Ines of rain in some locations so the result of all that rain is what you see here this is a map across the Houston area and Southeast Texas showing all of the areas that had flood water on them everything you see that's a nonwhite color everything you see that actually has a color here is somewhere that had some amount of flood water on the landscape and you can see as you get into those green yellow orange and brown colors those are places that had over a few feet of water on the landscape so entire neighborhoods that got inundated there were definitely deaths associated with hurricane Harvey unfortunately and so when we look at a storm like this it teaches us lessons that sometimes when we think a storm may come in and may be fast and furious we need to be really careful about how we forecast the duration of these events because even though Houston didn't get directly hit by the eye of Harvey this was actually one of the worst weather related events in Houston's history because the orientation of the storm allowed all those rain bands outside the eye to be pulled into the Houston Metro area so the question is how do we protect from future storms and some are advocating for the ike Dy and this new Coastal armoring plan where we raise levies we extend seaw walls and things like that to try to protect the bigger infrastructure areas now some argue against this because they say it's just really really costly to do this for the entire Gulf Coast and these places are still going to get hit by storms and may still be susceptible if we don't build huge 25-ft seaw walls everywhere and we'll see what happens going forward in the meantime a science that work on natural hazards whether it's flooding or whether it's storm surge and hurricanes we advocate for building less in these areas especially the unprotected areas of these areas and if you do make sure you raise the base elevations of the structure to be above what the expected flood or storm s surge level would be and then lastly if you can if you get enough warning definitely try to evacuate because it makes you less likely to experience right the worst of the storm and it also makes it less likely that people will be become fatality statistics from these different events okay so that's what I wanted to talk to you about about kind of where we are modern day we're still building in some of these areas but we're trying to make sure we increase the elevations for structures that aren't protected by big Coastal Engineering projects and again better forecasting trying to make sure people can get out of these areas right before the storm comes