2D Flood Modeling at Community Level Using HEC-RAS

so first of all you had to file new project so you will start with a new project and you will determine the destination but before all of this we had to choose the unit so you are going to go as a US unit or as other something so I'll work with us and the new project then you will start to determine the area that you will save your files so I'm going to save it at topic until the study ok and you will create your your folder and like a crass models and let's make an like blumburtt and feet file system a surprise ok and you'll worry about how to make the folders your spaces yeah yeah ok and then we will say ok so we will start in the project yes and then we will go to the rest mapper or to import our digital elevation map so we will get the digital elevation map from here open and so you will get the Train so we'll get create in train and it is recommended that the project spatial reference so he said here that you had to determine your data so I'm going to import my protection ok so I'm going to put it from a file I have so I have a file have a data and I'll tell the Harris to take the data from it ok and where can I find this projection do you know that you can mineral you can first of all you can import the digital elevation map with its projection nothing so if it's already projected it's ok you will skip system so if it is not projected you need two people or its projected or not projected and you want to transform it to another protection so you had to choose this projection from a file so I have this file is projected to an end okay and we will set up in so this is it will be an ad 1983 okay and stay playing North Carolina so this is my data I'll say okay and then I'm going to add the digital elevation map here I guess it's safe add it here and I'll go to this variable so it's it opens this one so 12 B up into here so I'll tell turn 8 okay so it will take my study because my study has been created before different yeah so can I put mmm I don't think so you had to merge them and there's a way to my seminar yes you will go here just for not ruining my files I'm going make a folder I have we'll save our files so if you want to merge digital elevation maps so you won't go to here at the arc toolbox and there is a way to do that so I got to digital elevation maps okay to merge them you will go and that management tools in rester and you will go you will find a YouTube videos showing you how to use this you will turn getting a rest earn your raster data set 12 be empty and arrests let's create raster data set and when you create this empty one you are going to do a mosaic like merchants is using but just for files and he will write that okay I got it so at the first step we just need to define that and kind of empty yes what this space and I'm sorry before getting from here from from raster you will do that okay okay let's go back here and let the closest because alright so I'll say from various project and we will go to Lumberton fill the study and trial is the grass is just created a file we just pretend it's a trial occurrence yeah I'll open it and I'm going to name one as Lumberton save all our fun yeah okay and we will go to the wrath lovers in the trains create new train yes I want to and here is the folder that will big the projection and then here is my digital elevation map 12 me here the measured one up him Vincent came to just make sure okay minute and I'm going to say create so it will take like several minutes to creating two readings this file okay and after creating our Matt so we will create the 2d flat planar okay so I have a bitmap I need to pick the area that I'm going to work on like the area that got the flock okay so this area is it will be a 2d finite element mesh okay some water goes inside and some water come outside okay and after defining the 2d flood area we had to define boundary conditions so for the 2d flood area you don't define boundary conditions on always outside so you may know the discharge at some point inside but will not be helpful you should know that point that outside the studio okay so you mean that for defining the boundary condition we just need to select outside part yeah I'm going to show you here so if my stream is like this and like this in goes like this so my 2d flood area we'll be like that okay so I had to know the flow here and the flow here and the floor here so if I know the flow here it will not be helpful okay because he will clade the too flat here and then he will know what is the flat here okay so and here we just define what is the flow at these three points and we will assign that the wire is is flowing by gravity at with its normal lives so we will get the flow so we define three other streams and one down the stream okay that's what we are going to do and for the flow you are going to define if it's steady or unsteady flow steady flow is for the flow that it is not a changing will stop that means you have constant flow like a river in normal condition without any flooding but in our case we have flat so the flows was normal but it comes for a high level and Zingo so it's unsteady flow yeah that is the difference between the steady and unsteady flow yeah and after defining our to the flood area and our boundary conditions we will assign something is called hydrograph are you familiar with the term yeah it's discharge with time Q with time in case of forever flooding the river is like in a normal condition but at the flood it goes very very high and then drop was done yet so this is the hazard this is the hazard Issachar so this hydrograph you can get it from the usgs so you can go yes this points to define that thank you for each each one of them and this Q is not it's not constant changing is that so I'm going to show you so here I just this is a station is coal lumber River near mixed so lumber River have many stations mixed on is the up one so you can assign a date to this is the the real time state flow in the river right now but I don't care that I care at the begin date of 2016 because there was a yeah and that one says October and the day is let's say it's 1 and here and let's say and let's say go look at the graph okay it was very fine here but just not that high as much this one by care from this point up to system so we can it change this to be 8 here's our Hyderabad this is the discharge with the time from October AIDS up to October 29 the hazard was exactly at October dance okay so here was the maximum visit rush this is at mixed mixed on is here and how you know these situations you'll get them from show you as she asked for her data for the nation yes here you will go to map all site this link is to all available water data for individual sites and here is the map so mall city is here so each one of this have a hydrograph this is the old addicted oh oh so I'll go here access data and you will go to the le data and then put the date so if you got the data or all the station that's some station you will have it so I have a station here and I got a station here and station here and one here but I don't have that so what I did is just assume that flow here and it shake the flow here because I have that but I don't have oh yeah kind of - yeah and there's other ways there's a program is called heck hms is this program is like make hydrologic study you will give yeah you will give him that rainfall in inches and some data about the area and you will say what is the hydrograph so it kind of created hydrologic analysis technology it's not our working ok needs did some information I have it but I didn't work in them so participation but first participation based on so actually USGS gives this fighter grass using the precipitation so they did this for this process for us because they put gauges on the weather and knowing that value off of the water as this gauges so he can get the flow that I'd love math but there's some software is using the precipitation flow in this variant and the geology and the topography of this area and how much the water did absorb it in the soil and other stuff like this and what it will need advanced parameters like I saw that because I try to do that to forecast yeah but it is hard yeah you had to wait for someone to get it and there are twisting difference here is Harris is using the actual data or at least the data that you introduce yes you can't you can like if you want to go back like so when you say on on has is a ten-year flawed or five hundred year floods so ten-year meet mean means that you are going to assume that it will be a precipitation like 20 inch or 30 inch so you can go from this point I'm going to assume that I'll have a precipitation of 20 inch and then go to head KMS using this precipitation to get the hydrograph and using the spider graphs in head crass to get the flop so this is the process you can start with the precipitation may get you mass and a glass okay now I have the hydrographs due to actual flow not a precipitation from 500 years ago hundred years so I can use this this higher gas in my models and then predict that but if you want to just based on this scenario based on a statistical base you say that for example you will have this kind of participation position and you will create the heck catch model model for the area yes exactly and you will create this graph he grabs his graphs from Nicodemus yes oppa Hydra gasps and you put it to the yes here's our so my city is here okay in this area so now I have the train here I closest but I have it here all right okay so I'll go here here is creating the 2d flow making the geometry of the okay so when I collect it here I'll see my area this is my area so now I had to make my finite LMS okay so first of all I have to determine where is my area I'm going to zoom in yeah here and this is one of the branches okay start this all right so let's say that I'm going to create to the floor area okay and I click here and it will starts from this point okay so here I'm going to click and go throw a block something adventists yeah but but you know the points that you know that is a charge this is a point this is a point this is one okay but the water is going to flow here you can go straight but I'm just making because you had to like confine all the world oh because the waters goes outside if you're not goes inside yes goody floor area and we will start at this point and I have a reading here at this extreme all these red lines as history and I have a reading here and let's go this is my downstream and let's close it just double click and say it's a 2d flow area and I'm going to say here's mine to thee I'm fine I tell my mesh you can make it fine by zooming the answers here is a point so you will go here edit and remove this point so you just like so we will remove we can't move the points in it move the point so we came up like that and one like that yeah it's so you can edit it as you like in here we can edit points remove this for me let me move it so it's okay like that okay so after that I'm pretty sure about my area so what I'm going to do double click on area Oh before double clicking we should remove this so here is my area and then go to to the flow area and it it to d4 and we will generate the computational point so I'm going to say it will be like 300 feet by 300 feet this is the measure silence okay and then generate the points up so I'll have one more than one 100 cell okay 100,000 cells so I'm going to say okay so generating the mesh so it's based on this and this the second thing is just make the boundary conditions so I'm going here at the boundary condition lines like it you can zoom out you'll see and here's the first of his dream we have and then after I have a pretty much control of the area so I can draw the boundary condition so the boundary condition the star from here going up to this point you double-click a thrilling finish so we'll say it's up one okay okay so we will have this long as the first boundary condition the second thing is get the second boundary condition which is here and the drove boundary condition line from here up to the ends and we will say it's off - okay and the third of a stream and it should be in Domitius is that right dimensions in domitius I mean yes outside but I think for this version is you if you make it outside it could work about I didn't try it but I always make it inside but sometimes it will not be accurate while I'm drawing the line sometimes it goes out because you don't see it works but I tried with the new version doesn't work okay let's do the office the downstream all right so I'll go the boundary condition we'll call it down one all right so after finish that that you will go to save the geometry data but before that we need to now we draw a boundary condition but it may not like we say client can side with the joints it doesn't relate it to the joints we need to connect it so what we what we are going to do is just to collect on this in edit 2d flow area and force the mesh recommitted to recompute with the new boundary conditions so he can compute because you know finite element is working at the joints but not inside the area so we need to force the computational of the boundary conditions at the show okay so we will say force the mushrik amputation so it can be computed where's the boundary conditions and then we will say okay so now we can save visually so the geometry data we will set it as and then closes the second thing is is to edit the unsteady flow okay so we need to load the diagram something so the first of all we have four data we should load it here the up one two three and the downstream so I click on up one when you click it this will pop up so we will pick flow hydrograph and he asks me about the hierarchy so I got so made a great data all right but I can't get it so Toby here lovely this is long river infested okay so I'm going to download the data from October 2nd and I'm going to say tables so it's a test okay here's the data you can see he had a date of this knowledge each 15 minutes so what I'm going to do is just copy this data and they get to excel or there's other way we can do that you can just click Save asks and if you can save a statist and then we will go to the grass you can make a new folder for everything let's make it up one save it and go to the Excel spc house and B takes as morning all right so this is just I think I'm I'm going to delete this lines so we will lose this deal in here we are going to use fix the start time and we will say October 8th so this is the format and and the time is zero and each interval is 15 minutes so this is the start time you it was a lot of finger prints here's eight okay let's just start over right here is the discharge values you can see it well go up to the next when it goes to like 7,000 or six missiles so all what I need is this column and I'll take it to control su Ming go to the head grass and they still control you right so what I'm going to say we put eg slope of distributing flow along the boundary condition we always put this value as point the Europe point five I'm not sure about this value but you had to put the value for it and it says the slope for distributing flow along the boundary condition okay okay but all all the all the tutorials I saw you put it this value but I don't know if it's going to make difference or not if you have any missing data you are going to end Internet plate the missing values and then you will say okay if you want to check double click it and load the data you will find it like this okay to save our time we can use upstream to as flow hydrograph with the same values and we are going to point missing values in the plot it as we had to still fix this time so we'll get at the time that's me all right we'll say okay we will put this one also we should download it but for simplicity okay this is the upstream the downstream we will go to normal dance assuming that the friction of the slope is Oh before that we will close it so we'll define everything we need to run it but before run it we will go to the rest bubble and we will go to the 2d flow area and we make a computational area here okay so we will before run and compute the 2d flow area hydraulics tables but we will redo this step before compute computational for the in our computational work so we will go to run and unsteady flow analysis here we are going to say compute but after defining our parameters so we will say we need to do geometry processor unsteady flow simulation we don't dealing with sediments we need post the processor we need the flow we need the depth we need flood plain landing so the start date wind we need him to start at the day yeah 0 8 October 2016 and starting on the zero we can make it zero and the ending time is the ending of this which is we can end at any time here like 20 October 22 12 2016 and then we will define the computational interval you can you have data each 15-minute file you can compute each one minute or each one hour but when you make it one minute it will do a lot of intervals so let's make it each one hour so can't do it so fast but to be accurate make it like 15 minute I did it one minute before but it crashed so it's one hour everything is okay don't say compute this file we will save them and we will say it's a planning plan and we will say ok you will ask about the short ID of the plan we will say one okay so before compute I saved a plan close it we will go to that here to the flow area it takes some time to compute the 2d floor area you if there's a problem with the mesh it will compute the tables with the shines and everything about there yet - do you know the input files is preparing the input file and I can ask you a question and so I want to know where their head grass considered the land cover or not what is the one cup for the houses here houses and whether it is forest there or building actually it's shameful but no it's it's a digital elevation map in there ok so everything in your digital elevation map it should be man done it so I don't see elevation of what of the earth Jeremy you want to take the surface you have the surface of the digital elevation yes if you zoom in in let's go here and here if you zoom and here you will find the pixels yes and because if you consider this land cover it it will destroy the flawed yes exactly but actually I think it's it should be mapped on the digital man here so because each point here you have its its elevation down yes you can see here here in this value each point here have its elevation 123 in this area it depends on the resolution of the initiative what is on that because it's your color yes here at this point is 1 2 3 so all this color is 1 2 3 this is 121 and this is 121 anyway we'll go lower it's 190 doesn't consider the surface roughness and manís ratio actually I don't I don't know because this parameters do control it in the digital mortgage money because when I was working on handkerchief as he is asking about the Mannings I think coefficients him stuff like this okay on that software you didn't use the land color just just a digital efficiently so the water run according to its knowledge okay goes from the heart to the loan so now we are really because he said compute computing to the floor area and then finally we'll say yeah here and we will stay calm here I hope it doesn't say this yeah it will run now so we will wait until you finish the analysis and then we will get it depends on the time interval that you choose from the verse which was one hour so it will not take time if we define it as fifteen minutes I have to leave my TC do it and come back in the next day so this is it depends on the mesh size also because we define it as 300 if my model is 100 okay so yes okay and this thing I see the basic behind it is kind of completely the same as houses but with some minor but has us to find that and I think it's do I think it has its do something like what I'm going to show you right now because I found it on a website in this website you just say I have the gauge on labra River say it's 22 feet and he will do he will grow the floodplain oh yeah Oh you so that's powerful tomorrow I mean what I go through you actually you said that you will be I will be in lab all day and even I can come campus after dr. Coleman at 3:00 before so so after food does it matter for you that's okay that's great so I will be here at around 4:00 so I can come to my office and you or your office and we can work on the hardest to fix the problem and I need to give you more information about the the concept behind level to miss you you if you don't want to use it from the hazards and access you can start hoping that because this is really easy and this is a simple form of formulation so you're calling on the art lab using MATLAB the first master is grabbing the shapefiles from you are going to grab the shape filing from as a stand not so for the level one I grabbed it from houses but for level two i grab it i had this there's some things and the same as you I have the point by point building values and track listings and I ejaculated you know I wrote a code for that to calculate their losses but what I used is just the policy of process concept of houses they are calculating the last estimation and then and also I calculated them all so I use the formulation for their losses because this is really easy you just need to multiply the devil their percentage of damage times that the replacement cost so you need to have the replacement cost and also based on the value of the building and the characteristic of the building you get the percentage of damage and this is the goal I already got the percentage of damage from the flood characteristics and the bill yes exactly so let's say that you have a you have a depth on a specific building you have a depth of flooding and then based on these steps of the flooding you will go to the best damage function you will get the percentage is yeah it's really easy yes if we have the tough lot and we have the bullying levels yes and we will put them together a bit of slant height using damage function we get the percentage damage multiplied by their placement that you will get the damage cost yes if you want to use it there we totally helpful to think so you don't say you there's an F here I got a very useful websites let's just say the fluoride is that and you'll make a flop blame and showing you the most damaged building and bread and other food yeah and also calculate that goes it's it's the state of things very healthy but he don't think it's accurate because the floodplain it doesn't look the same like what happened in the reality okay maybe you the specific algorithm for solving it is not this is cool stuff river fly open so he the river is there's a gauges on forever you just say that they get you will reach it a level of 50 feet 20 feet he will he'll play to them this is not the website but this website say that showing you 100-year floods of the area yeah just a flood plain man okay this is based on the theme of water yeah actually this is you will just click on a point here and you will get the base flood elevation is 120 300 just one of the deals one you can download the maps and I think the maximum flood I got is 123 or 124 this is your first year you yeah the Atlanta one to finish I'm justice I'm in the third year and I don't have any plans oh yeah but I think it just both take four years yeah so I can virtually for me because I didn't start with a specific you know project nice to reach between two three main project cells because almost the drafts loosely the beach to students about see don't know what he's going to do is this be yes so he have like a body and he wanted to use this body to do something yeah so see who he will ask you what is your plans and you come to your project and you don't know about that's what Mikey drafts or did so what is your plans my master ceases was an earthquake it was on a structural level and it was an element level not a structural levels because wasn't sheer walls so I transferred from element level to community like and from an earthquake - yeah so you had to read more and if I read I will not find my way because I need some guidance yes exactly this is a problem that I had with my past because I changed this object I didn't change dr. Mann we change this object three times and every every time it takes about six months or even one year and to say that okay this is not working with the change to actually depends on how lucky are yes exactly I get the best from the first maybe you in diverse like by thinking what is the same he's doing some lab works yeah yeah and finally he get his way hospitals yeah yeah but if someone find his way from the first year so yes that's right because I think if you just focus on one thing for one year it will be done for sure yeah do you think so do you think so one year yeah yeah so what about the other projects that you didn't get in like paper yes I started one paper and for this one we will stop these another one in one month if not no no not a lot of in in the lab work but we in the flood I'm in the beginning was that so I'm going to publish it as soon as possible it's my goal yeah so here's your going to make a scenario okay so we will say that the flood height now is 12.5 feet so if you are going to increase it so there is no damage here okay but let's make it at 15.5 feet so since there's not damage so let's make it here so here we have 94 buildings get damaged this is only for the state of North Carolina just always state that means this but actually it is not accurate because and he said that in the worst because you can see he's just depending on this gauge Oh just freeze the water at this gauge and see what's going on there but the water doesn't come from here the water is coming from outside the city yeah and we have some building get damaged in this way so so the damage is calculated according to this version and he will show you Shea Falls of the building here and how much damage they will get this is more damaged more than that if we increase the flood to the next one point you will see we have a lot of damage here and if you click at the building damaged you will get tabled from 0 to 1 feet how many building get this levels and what is the polling that have more than 5 feet okay so you can have it like that we have commercial bowling with 5.5 feet this is the losses the stuff like this I don't know if it says this is working in the same way but but you say it's block-level not yet not yet so let's back to the class he finished let's go to the rest mapper we will oh yeah we will close this and open it should we should have results yeah here we will say we need the dips so here's lips what we will get so the mesh is very rough yeah here's the water I'll go through my area is here this is not a kind of line because the Misha is very rough so you can see it goes very wide oh yeah but if I make it smooth as mine will be better than that okay and so you all can see the water I'm talking like that so let's you can see the velocity that's one of the feature that has don't do that because has is just giving there yes and also I think it doesn't give it with time yeah just get the floodplain that like existing excellent yes something like that yes exactly that's all okay and you Thursday YouTube that you I can't send it to you it's do all the steps that I'm done okay yes we'll be okay

Channel: Omar Magdy Nofal

Views: 27,798

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Id: AotdZKrJ2mg

Length: 60min 9sec (3609 seconds)

Published: Thu May 31 2018