Terrain Modification in HEC-RAS Part 3: Dams, Levees, Channels, Buildings, Basins, and more!

hi I'm Craig with surface water solutions welcome to our next video in this series on head grass in this video we're going to cover terrain modification this is our third terrain modification video the first one we covered a cemetry the second one we covered how to get rid of no data values and in this one we're going to play civil designers and put in dams buildings levees detention basins whatever you'd like to put in if you can put fill there or excavate it out anything you want to add to your model we can put into the digital elevation model by using a 1d geometry now we're going to start with a 2d model that we've already made in some of our previous videos this is uses the same terrain sets that we used in our previous 2d models on what's new in heck res 504 we're going to go ahead and take this same data set and let's pretend that we are representing a developer and we have to put in some sort of box warehouse or some structure here that's going to be in the floodplain well typically you're going to need to put in a detention basin or some other feature to be able to mitigate for any impacts to the flood levels well we're going to have go ahead and do this with every single one of these features that you see listed here let's go ahead and start with the building though the building is going to be the simplest one to do it's just a square in this case and we're going to put this in as new geometry I will call this one one the terrain this will be just for the warehouse and but actually we can put every single one of these features into the same geometry we're going to define them each with their own River name and a river alignment this is a river centerline but this is really a bit of a hack it's going to represent the centerline of your levee of your building of anything else that you're going to draw so in this case I'm going to start with a building I'll draw the centerline here draw it's coming this way here's my building each one of these features is just going to get a single a single reach for its alignment the bank lines as we were doing for the symmetry in this case are just going to represent the lateral extents of your building so I'll go ahead and put a bank line there and a bank line there and then I'll add a cross section on either side of this which will represent the longitudinal extents make sure that your cross sections cross each one of these three lines not the five that you need for 1d hydraulics but just the three that you need for terrain manipulation once and only once make sure that the none of these other lines crossed with that I have now defined with these four lines the extent of my terrain modification for the building will adjust those sections in a little bit once we put in a few more features let's say we need a detention basin as well well we're going to use the same concept making a river and we're gonna do this about a hundred times here where we start editing and then once we have the edits in there we have to stop editing save the edits and start editing again so if my detention basin here has a center line that looks something like this I will call this Basin basin we can now define with the bank lines the extents of the excavation so this will be the outline of my basin and I'll make this somewhat rounded on both sides and then we'll put in some cross sections the cross sections themselves sometimes I like to day light them on the ends and leave those ones at the ground elevation tapering out to my next section will show you that how that works when I get into the cross sectional data I'm just going to define this one with just three cross sections for now and again make sure they cross once and ever only once you will see missing reach if you missed this with one of your sections and you won't see a value here so you've got to make sure you see values for every one of these when you're done drawing them that shows you that you've got what you need here we do need access to this thing so let's go ahead and put in a roadway as well so I'll do that with a river centerline again this is not a river this is the roadway alignment centerline I'll connect this little roadway here right across the Brisbane River to here it's not gonna make a whole lot of sense but this is just for fun so I'll put this one in this could represent the bridge deck it could be a flood way or Arizona Crossing whatever you want to call it I do need Bank lines again these are going to represent the edge of the field now if I've got vertical walls on the edge of this I can just follow right along with this thing so I'll go here from this end to this end and again do it this way with a cross section that's going to just be on the ends here and interpolate everything in between and so again this becomes the extent of my roadway between all of these lines so let's continue here and see if we can put in a levy not sure if this will make sense to put it here but let's go ahead and connect dry to dry so that's we can block out this flow and open up this flood plain for developments or whatever you want to do here so with my River I'm going to just do a center line of a levee coming along my river here and now I'm back into the dry in this case I'm gonna keep this one fairly narrow so I'm gonna make sure that my bank lines follow that fairly closely so again stop editing start editing do this over and over again they'll show the edge of my levee fill footprint basically this is the toe of my fill and then I'm drowning here and I can manipulate the cross-sections any way I'd like so what I was gonna show you here is just how your cross-sections are going to follow the alignment even when it's on a curve so if I edit my geometry I put one cross section in here one cross section out here and you'll see when we interpolate this that it's going to follow this curve the other thing I noticed here is that I've actually got some water that the lidar shot too and you can actually tell here that's when you look at the terrain that it didn't get included in the terrain so just like in our bathymetric exercise that we did just a in our previous video I'm going to go in here and actually this one becomes a river centerline so this is not a building centerline or anything else this is actually the river so I will go ahead and start up here where I've got some big cross-sectional data and let's bring it through through this Dam and this is one thing that you're going to need to do if you have a structure that's already been included in here and you want it to breach it or do anything you're gonna actually have to take it out of the terrain so here's one way to do it I'll go ahead and make bank lines of long my water's edge like I did in our previous exercise for the Brisbane River and so along the edge here I'm going to go right through the dam and same thing on the other side come around here and make this my terrain manipulation so I need to add cross sections here as well I'll just put a few of these in you can get much more detailed than I'm doing for demonstration purposes I'll just put one there numbers on all of these once I put the dam in up here I might try and block up some water prevent it from getting downstream and I'll put a diversion up in this area as well so if you were a dam designer I'm not many dams going in these days but if you were gonna choose where to put a dam you might want to look for some narrow abutments that would store a lot of water behind them in this case we would be flooding out a lot of people but this is just for fun so I will go ahead and start a river centerline here going from bank to bank and we'll call this one dam and I should I have a dam already that's we'll call this one dam centerline centerline was taking out a reservoir behind this dam what I'm going to do now on my bank lines you have to make an initial guess at this how wide your section is going to be and when I'm up on the banks I'll have a little bit of fill when I get down to the river I'll have a lot of fill and so I'm gonna actually move this line a little bit outward when it's in the middle just to represent how high the filled would be so with my cross-sections now I'm going to edit these and I'll put one right here and one right here and on this end I'm just going to show you one feature one thing that I like to do to these I I could do this on any of them I like to have my last cross section actually daylight to existing ground so that it transitions gradually got to the section that I want so I'll demonstrate that here we could do this on every single one of them just for time purposes I'll leave that out on most of them it is something that you could do on each of these to kind of nailed down your transition zones a little better so the next next thing I'm going to do is connect my channel from here over to here and this will be an overflow spillway something where my dam or my reservoir was it fills up can start spilling over the sides here so with my bank lines I'm going to start editing those and same thing as I had with the dam the fill is going to get a little wider near the top and narrower down here at the bottom yeah do that here come down this way put in some cross sections and we'll put one on the upstream ends if you mess up as I did here this river centerline I put it in as the wrong kind of feature so I'm going to start editing River Central and put that back in until anything crosses it it doesn't recognize any of the geometry until my cross section start going across it so with this one I'm going to call this detention no sorry this is diversion and I'm gonna put a couple of cross sections across it and again any of these things that you if you make mistakes while you're drawing them you might want to get familiar with the editing tools if you haven't done that yet already these editing tools here where you can actually click on the features and delineate them any way you'd like so I'll show you that just a second once I've got these ones drawn make sure I've got numbers for all of them if I want it to click on any of these and move them around I double click I can move the vertex up here or I can add a vertex in there by clicking hit escape and you're done control Z as you could before you couldn't do before that's a new feature which has been very handy with that I think I have Jesus I've got seven of these things which I think cover most of the features that we've got here we've got a diversion drain channel excavation going through here it's a canal essentially we've got a dam that's going to go across this way blocking flow up we've got some some excavated but the inventory that we're gonna pull out here and remove this dam so that we could put it back in as a 1d feature later we've got a levee that's going to block some flow here we've got a building that's going to obstruct flow we've got a detention basin right here and then we've got a roadway that's going to cross the Brisbane River so with that I need to define my geometry so I have to save this first save my entire geometry and now I need to exit out be sure to exit out of rays mapper before you go into the geometry at get some issues going back and forth between the two so I'll close out of razz mapper open up my geometry window it's blank right now but if I browse to the one that I just created which is this one right here called terrain warehouse it should zoom me right into these features so I see 1 2 3 4 5 6 7 features I don't see the bank alignments that I drew but I do see the bank stations where they crossed now first thing I need to do is and it's my cross-sectional data and I'll do it in the same order that we did our other ones in and I'll just leave this up here while we edit the cross-section in each of these cases I'm going to use my bank lines as the extents of my terrain manipulations so basically I'm going to blow out all the points in between the banks and when I stick these back in let's make this Costco's first skyscraper so there's one station and I'll do the same thing on the next one pull it in here go out to the bank stations take everything beyond the bank station paste it back in here and give this a height of 80 meters so when I put this building in you can now see as I go back and forth there's my building section so that's my building taken care of let's go in here and now do the detention basin same thing I'll edit the cross-sections here take this one right here and we're going to go in and in between these Bank stations right here let's this in this case we're going to add some additional points so I'm gonna let it daylight out at the end of this one and I'm gonna make it say a trapezoidal channel that comes down to an elevation five and in this case we can design the side slopes a little better you could use the channel improvement or channel modification tool it's called now to define this a little better with the daylight lines in this case I'm just going to put in some values here that to make this trapezoidal do the same thing with this middle cross-section here and this one will be a little wider than the other I'm gonna leave two of these blank so that I can put in something trapezoidal at an elevation of 20 I'm just guessing at some numbers here and I'll do the same thing on the other end so with that when I put this one in you're going to have three cross sections that are going to get interpolated out to these elevations and as I scroll through these you can see my trapezoids here so with that I've got my detention basin taken care of the floodway I'm going to do this one fairly simply and to just make it a flat section across the top again blood everything in between the bank stations put this one up and I'm just going to give my floodway an elevation of a 17 so this will be more like a bridge deck I guess and I'll do the same thing on the other end this one will be sloping up because the other side's got a hillside on it so for this one instead of being flat like our building was going to have a longitudinally sloping future here so in this case it's going to be up to say 44 existing ground and what Hecker ass will do is just vertically interpolate between your new topo and your old topo now let's get into our levy if you see a missing reach which I've got here you can delete that reach and by going to your full list here this is one that came up because I had started something and not finished it once that's deleted you can see it's going here now it looks like this one came out and this is a good exercise to show you if I missed my cross section if it didn't cross this one here I'm gonna have to go back in and add that so this is something that I messed up but I'm gonna show you how to do this anyway so maybe it'll be something that's you run into as well if you ended up missing one of the sections here and you can see here when i zoom in my cross section doesn't exist there so I need to put another cross section back in I had not actually hit this reach with it so it just sat there on its own as an orphan reach so if I go back in here now and put in a cross section that does cross them all it gets a number and so now I'm good so when I stop editing this I can exit back out of rass mapper and go into my geometry of your and there it is so with this one I'm going to go and put trapezoidal fill section in this case editing my cross section going in between my bank stations and you can always have a look at at these Bank stations here from 9.7 and if you don't see what I was doing before from nine point seven to 49 I'm using these stations here which our giveaways because they get a tighter interpolated section that's how you can tell where they're at those are the sections that I've been pasting around here in this case now I'm going to go up instead of down like it in my detention basin I'm going to go up say two like this one twenty two forty so I've got a 10 meter horizontal maybe go up to 25 it's a fairly high and steep levy and I'll do the same thing on the other hand again look for these longer ones here to leave everything in between and I'll paste this back in leave them to blank so that I can make my trap is on a levy section in between so with that I can have a look at both of mine there this is my end sections and it's going to interpolate those along this lie now let's go in and put our birth imagery in for a symmetry it's gonna be the same thing I'm going to go out to my extents of the bank stations blow out everything in between and we'll go ahead and leave a couple of things blank here you could leave 3 or 4 of these and put a low flow channel in I'm just gonna make it flat across the bottom well in this case let me go ahead and show you how to do that if I come in here in my both Emma tree and blow these sections out I'll take this one out to 35 take this one out to 65 and then right in the middle of the channel maybe right here in about 45 I'll put a low flow channel here so eight I just see if you like how that looks if you don't like it you can move it away you could use the graphical cross section editor anything you'd like to see so there's my bathymetry I'll do the same thing now here on these other ones just to keep it a little quicker just these ones out and maybe two sections in between I'll show you can do it just with a single section as well fifty and twenty little section in there and on my last one let's try doing it with just a single section in here a single point in the middle actually no this one is there gonna be the end section right here which we're going to use to interpolate out to this one and just have a look at what this looks like in the end we interpolate out here you'll see that it's going to gradually transition from one section to the next using that centerline alignment again you can add as many points as you'd like you could take real bathymetric section data and put that in there now two more to go my damn I'm gonna put this one in here edits the sections in this case I'm gonna blow out what's in between my bank stations and let's do this as a single trapezoid and then our end sections as we discussed I'm going to go ahead and that one and put in a little more detail I'm gonna let a transition gradually from the daylight section on yet so this one is going to be at 36 let's put the dam up I'm saying eight meter elevation and will gradually transition out say from 52 lady just making myself a little bit of a dam there do the same thing in the middle and I can see where I'm at right there in the middle this is going to come way up this is a cross-section going right across the middle of my channel so I need to come back up to the elevation that I was at right here which is 38 so I'm gonna make a 30 meter high in the middle of this blowing out my sections in between 60 and you can see what this looks like and adjusted as needed so there's my damn coming through the middle and at this end one right here again I'm going to use this one here to daylight ooh and then this one here to come back up to in this case it will come down to 38 meter in elevation which is the crest of my dam so I'm gonna come back out here to and Bank Station will is out and put in a trapezoidal dam that's going to be sloping a bit but let's come up here 250 I've got a section there and what you'll see that is that this is going to gradually transition back to the road to the elevation of the existing ground right here so last one and these are not pretty structures but you'll see what they look like in the end and then you can make these adjustments as you see fit in this case we're going to just put a diversion in I could just allow this one to transition out and maybe we'll do that to show you what this looks like when I edit this cross section I'll leave this one as it was since this is a Little River Way with an elevation of about 30 and then as I move down into the middle way up 1020 meters higher and then I'm back down below 30 so I'd like to blow out everything in the middle right here and I'll leave the other sections as they were I want to blow everything out in between here and go to my bank stations paste the rest of it in and this will now be an excavated section that I will put a river channel and I can choose my width here and choose my elevation let's have this one going down to the same elevation as the others I'll take it to about 32 so we can get some spill across that I could build myself a spillway in the middle of this thing let's take this down from about a hundred to maybe 300 big wide so let's see what this looks like I might narrow this down just a little bit just to show you how you can use the graphical section editor I'll take this one and move it around that way that can be a nice handy way of making some very rough changes so with that I will edit that and save my geometry that's all I need in geometry now I just need to take this thing and turn it into a terrain so I'll close out of the geometry editor here open up my rez mapper window and in res mapper I now have this terrain called 1d warehouse so I'll zoom to this one here and you can see all of my features 1 2 3 4 5 6 7 features with this one I'm going to right-click export the layer remember to only do the channel on this one if I had drawn this one and wanted to interpolate from the N sections or the ends of the cross-sections I could do that but in this case I have actually deliberately drawn the channels to be the edge of my terrain manipulation so I'm going to create this from a geo TIFF and make this one at 1 meter resolutions of 1d terrain warehouse and all the mitigating features its save one meter off you know and it's going to export much rain again it hasn't put it anywhere yet I need to manipulate my terrain and create a new one by merging these things together so first I'm going to stack these things on top of each other now this goes back to the previous exercises that we did here is the one that we've just done the 1d terrain warehouse I'm gonna merge it together with my Brookfield 5 meter but I'm also going to need to take my both Emma tree which was in the river channel and my no data values and stack those as well and if you didn't catch those in the previous videos you might want to watch those as well remember no data goes at the very bottom that will blow out you know data values and it'll see right through them this is my existing terrain as it was when I received it with no modifications I'm gonna take the bathymetry which is my River but the imagery put that on top but because I've got a bridge going right over the top of my bathymetry as well I'm going to take this other one and stick it right on top which has my seven features here that I've put in don't ever leave this as just terrain we're gonna open this up and call it say merged warehouse more descriptive on that but for our purposes now that's what I'm going to call it so with that I'm making a brand new terrain here that I can then use as my project conditions terrain and then I can save my geometry that I've already run to make this floodplain that I've already seen here and make a new geometry that's exactly the same I'll save the geometry as a new name and then I'm going to and puts this terrain and as an association and when I run that I can compare them and have a look at the two so now let's see how we did I'm going to turn off my geometries I'm going to turn off my results my map layers let's turn everything else off get rid of this one and now let's see what we've got here I've got a diversion drain that I'd put through the mountain here I've got a dam that I built here that's an ugly one but it is a dam here's the levee here's my building here's my detention basin and here's my roadway so we did all of those features and maybe about 15 minutes here and you could manipulate these any way you like now I'm gonna run this again so I'm actually not going to walk you through that in this video but I'm going to reassociate the terrain so with this one and show you a comparison between the two just for fun so I just ran that one let's see how we did here if I come and check out our new project and turn on my depth map I'll change the scale here to less than 50 meters quite deep for the legend now let's see what happens with the flood down again now I'm I can animate this anyway I like cut cross-sections through it it doesn't look like it's what happened is in this area and we put in the bridge deck but we would now have to put in culvert barrels what I've done is backed up with the bridge deck I've actually built a dam across the Brisbane River it spilled into my spillway you can see around the building what happened there my other dam is holding water back as well I've got the this existing dam that disappeared and now my levee she didn't hold water because it's leaking I would need to put a brake line right through that in order to get it to be honored but that's all just for fun here let's have a look at our particle tracing and see what's kind of cool the features we've got going on with the Eddy's all this turbulence that we've got so as it goes around this bridge and shoots around our building and then back into the channel so essentially we've diverted the Brisbane River right into or whatever so yeah this one would need some work to play around with but you can see how we used 1d geometries to manipulate our terrain you can put in any features you like and then run them as 1d or 2d a couple of 1d 2d whatever you'd like to do so I hope you enjoyed that we'll play around most more of these come to a class if you want to see how to do this live or join one of our online sessions just check out our website at surface water table is if you want to know a little bit more about this so enjoy it I look forward to hearing from you thanks

Channel: The RAS Solution

Views: 50,455

Keywords: HEC-RAS, terrain, 5.0.5, DEM, digital elevation model, dtm, digital terrain model

Id: x4jWLjMx8zQ

Length: 27min 28sec (1648 seconds)

Published: Sun Aug 05 2018