Download and Install HEC-RAS: Tips and tricks for getting started

hi I'm Craig price with surface water solutions welcome to our next tech razz video this is actually a bit of a prequel we're going all the way back from scratch starting with just Google and downloading a grass the reason I'm doing this we've got about five or six different head grass courses from basic 1d and 2d sediment transport damn brake hydraulic structures each of these courses starts you from scratch essentially and we go through the process of downloading and installing a grass and make sure you're up to speed on getting rasz mapper imported and what we found is that those who have taken one or two of these courses end up having to sit through the same lecture multiple times so I've just figured I'm gonna put this out there on YouTube we'll make it free and everybody can have a look at this in the end what this gets us to is the step where we're ready to start our model whether it's a 1d model a 2d model hydraulic structures model whatever it is you want to do essentially these days you're going to want to have hair as open with Raz mapper so that everything can stay geo-referenced so just to give you a preview of what this video is going to cover first we're going to just walk through the process of downloading and installing hair as we will grab some terrain and projection files then set up a folder structure we'll start a new head grass projects put the unit systems in there open up as mapper set the projection get our terrain imported and then add the web imagery and some static imagery we'll check it make sure it's good before we're ready to go and then we'll be ready to start our model so let's dive straight into this just starting with Google now you may already have these steps taken care of you may already have HEC res installed on your machine in that case just forward through to the topics that are relevant to you now the first thing you're probably going to Google is going to be the term download head grass and of course that should take you straight to the HEC web page I wouldn't download it from anywhere else there are people out there trying to charge for it this one will be absolutely free for you and if you click on that it should open up a window for you and bring you to the core Engineers website now I recommend driving to London with the example data sets that way later on when you get into some more complex modeling like linked 1d and 2d couple of models you'll have some examples available to you with these things already set up so when you click the download button down in the lower left you'll see what's going to get downloaded you probably want to set it up to just open automatically when it's done that way it will execute automatically otherwise you can just open it straight from the download folder once it's done now once you do that it will walk you through a couple of questions and most of them you just hit next and proceed through the steps now once you click on it it should open up and extract by itself there are a few things I would probably want to put out there as a warning they'll make sure that you're running a 64-bit Windows operating system and make sure that you've installed all of the updates just to create the conditions go ahead and go to the next screens I do recommend clicking on the desktop shortcut and adding it once it's in there to the taskbar and to your frequently used programs if you have a 32-bit system or you haven't installed the latest updates from Windows including the latest dotnet framework you may end up with some issues where you're not able to run res mapper which is a 64-bit program it'll just walk through the rest of these offices fast-forward through this while hit copies through just in the interest of time and there's no licensing requirements on this one so once you hit finish you're good to go now you should have a new icon and so once it's installed all you're going to do is just click on Windows button and there you go you've got a new software so when you click on this and open it up it's going to ask you a couple of questions if you didn't install the data files or the example data set some it to do that next you'll also see the unit system come up here in your default minds already in SI units years will probably default to US customary from the very GetGo whatever you tend to work in most go ahead and change that let's go into options and have a look at the unit systems it's it won't keep this toggle on even once you've toggled it it'll go away again but just whichever one you're gonna work in hit ok now our tutorial models for our classes are always set up in SI system so that's what I'm doing here and you'll see what it defaults to right here ok so now the next step on this one I'm going to table this for a minute now that we've got this open and installed I do recommend before going any further though first open up as mapper and just make sure that it opens for you if it doesn't open then you've got some other issues that you can have to solve with some IT support or making sure that your Windows is up-to-date so with that the next thing I wanted to dive into before we start downloading or opening files or starting new projects I'm gonna go back and cover a couple of suggestions on the folder structure so we've got this manual that I think I've got a version of this one that's where the first workshop at least is available to download for free under surface water dub is slash workshops what I'd recommend though is before you start with anything set up a folder structure that's going to make sense to you so right here I've got one suggestion but your IT department or others might have other recommendations to be consistent with how your geospatial data are organized but I'm gonna suggest putting these seven folders or subfolders underneath of a project folder that sits right on your C Drive or somewhere where you can run the model without going to a network drive without going to I or without going to onedrive if you try running it on these cloud servers or these network based servers in the beginning you're gonna have some issues so I would go ahead and start a brand new project a brand new folder and put that underneath the C Drive so I'm just gonna go right here onto my file explorer directly under the C Drive and make a brand new folder this is the folder where I'm going to store everything related to this project that we're going to be setting up now you can call this one whatever's most relevant for you in our case we're going to be setting up a model of the Brisbane River so I'll put that in right now Brisbane as my folder name now underneath this folder I'm going to put in these seven folders are these sub folders that I've listed here and as I type each one in I'm going to explain a little bit about what each one is for aerial photos if you've got any static aerial imagery I wouldn't use the big ECW files or anything else they're just something that is the static images that correspond to your particular site area for hydrology this will not be your full hydrological model this is just the boundary conditions that you're going to use in the hydraulic model land use in Hecker as terminology that refers to roughness so if you've got some shape files of the roughness coefficients that's where you can put them number four of the projection I recommend putting one single projection file in this folder and only one that way everybody knows what your projection is going to be for this particular model the results pet grass is going to make its own results folders for you but this is going to be the one that you're going to save for delivery to appliance or to the stakeholders and it's going to be renamed to the naming conventions that you'd like to see the terrain is pretty self-explanatory we're going to put terrain files in that and then anything that you've already delineate it with a shapefile I'm gonna make this shapefile subfolder keeping in mind that now in the latest version of Hecker as you actually also get a folder called features and that will be there and that will have the shape files in it that you create directly in hec-ras now this I number these one through seven just so they come up in the top you're going to have hundreds and maybe thousands of other files that go into this folder and so to keep these other folders and files separate from the ones that you have defined I like to keep these numbered as so they stay up on top so at a bare minimum in order to start a project that's got the geo reference basically you're going to need two files you're gonna need a projection file and you're gonna need a terrain file I'm going to show you a couple of data sources for grabbing terrain data for free it's going to be different in every country and you're gonna have different repositories and different free DM sources and paid DM sources that you can grab from your own local councils your own government or private entities in our case the model that we're going to be setting up is in Australia so I'll show you some Australian data sources here and you can just substitute these with your own now one very handy repository on that I guess I will mention for the globe if you just type in open topography I think this is a San Diego State server that hosts all sorts of topo data that's available for free if you click on that one it it'll take you to some data sources go into your raster data that's what you're going to want forehead grass and then you can find the SRTM data right here which the S stands for shuttle mission and basically anywhere on the planet you can then grab your terrain data that's that's something that might not come in in the right projection for you you might need some GIS skills to the how you're going to project that out to a flat surface from the spherical coordinates but and and again the srtm data that's at a 30 meter resolution that comes in at one arcsecond I believe a sixtieth of a sixtieth of a degree around the planet and that's not going to be good enough for anything and any channels that are of you know smaller than a couple hundred meters in width so it's great for catchment or watershed delineations but other than that it's just kind of background data that you might want to use you're gonna want something a little more accurate so I'll show you with Australia where we can grab Bob data that comes in up to about 1 meter by 1 meter pixel so if you just Google Australia elevation data I like this one here Elvis that's the one where I go to grab most of my Australian data easy to remember with the funny name when you click on this one it's going to take you to the spatial reference system here you can click continue and this is going to walk you through the process of figuring out where you're at in Australia and where we're gonna grab the data so I'm going to zoom in here the project that we'll be working on is in Brisbane along the Brisbane River I don't want to get too urban so I've gone upstream a little bit we'll zoom in on this one here it's the gold creek reach of the Brisbane River and I think gold creek is this tributary right here that comes in and this is what I've been using for some of the online courses it's got a couple of us got some big rivers some small rivers a little bit of urban a little bit of rural so it's a little bit of everything and so that's what I've provided to you for any of the online courses that we take but I'll show you how to get it for yourself as well so if you wanted to get this whole watershed here you know you could you could maybe grab a little bit larger area that I'm showing you here but what it's going to check for you is what data you've got available now down to one meter by one meter resolution you've probably we got thousands of tiles well from here we've got 844 so this is a 844 square kilometer area and these are going to come through in 1 kilometer by 1 kilometre grids at 1 meter by 1 meter resolution now if you have 844 of these things to deal with you may want to use some stitching software you could do it in that grass I've actually done this in the rouse mapper and stitched together an entire 1 meter grid ends up being a couple of gigabytes in size what I'm gonna have you do just for the purpose of our online tutorials is to just grab this one because there's only one at 5 meter resolution so once you've grabbed this one and hit download it's going to ask you a couple of things now it's gonna ask you what coordinate system you want to be in you may not know that quite yet I will show you just shortly here where we're gonna look up these map grids in Australia we're pretty much always going to use these UTM zones for the mga GDA 94 in our case it's gonna be sown 56 for Brisbane now you've got a couple of choices in your output format you could get an ASCII grid I'll show you what those look like I like the geo tips but it doesn't give you much ability to edit those later on now I'm in engineering and I'm just putting my info email address in here and confirming that I am a live human and it will just start the extract and tell me that it's going to send me an email so I checked my email it tells me my data's ready and watch out you don't want to download the file that's down here at the bottom well you can't download it but that's not your data your data is right here if it doesn't come through in a live link you can just take this put it into a new tab and it'll be a zip file that's going to ask you where you want to download it so I'll just fast forward as this thing downloads and show you where it showed up in my download directory so it's gonna call it like a clip dot zip clips um number dot zip and you can then just unzip that one I'll just put it right back here under the same directory and then you can see what it's called now I do recommend going in and renaming this one once you've got it you're looking for a couple of things number one it's going to be the ASC file if you've downloaded it as ASC or as a tiff file depending on the format that you chose in our case I chose a actually a tiff format and I'm gonna go ahead and rename that one to tell me something about the file itself so mine again has this clip name what I'm going to call it I'm gonna go ahead and rename this one in our case this is the Brisbane River at Brookfield so I'm gonna just give it a more descriptive name Brisbane River Brookfield five meters so it's good to say something about the data source also this came from GSA and that way I know the resolution I know the data source and I know something about it if you just call it something generic it's gonna be very hard to remember later on okay so this is the terrain file now it's a raster grid digital elevation model and it's projected like I said to zone 56 now let's talk a little bit about the projections because the next thing you're going to need is a projection file now to me the best source for projection files is this one called spatial reference org you could just Google spatial reference to remember that a projection file is a spatial reference system and SRS so if you just go here to spatial reference org and click on that one it'll open up a new window for you here with the spatial reference website and a little search bar where you can type in the projection file that you're actually looking for now how do you know what projection file you're gonna be looking for that's something that you're probably gonna have to get from the client from the stakeholder from the end-user what projection do they want to see the results in you may not know that and if you don't then you might want to ask some questions around but if you are unsure then you could just go into a map and typically the UTM zones are the best place to look for where you're going beyond the planet so if i just google UTM zones you can see that it's divided up I think the planet 360 degrees around on the earth divided into six degree increments so you've got 60 UTM zones here are the ones for the u.s. the ones we're going to be looking for are in Australia and in that case it's fairly straightforward you have a set of eight projection files that typically covers you anywhere you're gonna want to be in Australia so this one right here is a good grid for it time if you're in Australia you can see the eight of them right here here's a slightly bigger version of it 49 it's just a little sliver I in Perth I work in 50 out in the goldfields will be in 51 Adelaide gets into 53 54 Tazzy and Melbourne are in 55 and then Brisbane sin 56 so if I know that and I know that I'm gonna be in zone 56 I can just go ahead and type in right here zone 56 other type in Australia and see what that gives me hopefully I'll find the one that I want and the most recent one this GTA 94 one is the one we're looking for now epsg one thing to remember here the P stands for petroleum and the petroleum industry has a vested interest in being able to go back to a given spot on the planet and figure out where your where your borehole was and so they have compiled pretty much any projection except for maybe local project grids but most projections on the planet have been compiled with an epsg code I do recommend cataloging math so that you know what you're working in what you're looking for right here is this prj file so I'm gonna take this prj file right here download it it's gonna give it this name with the epsg code I do not recommend keeping that name so I'm gonna go ahead and show this one in the folder grab this prj file right here and I'm going to start now but with my folder set up and go back to this folder that I set up here under Brisbane and remember I put a projection subfolder there I'm gonna paste it in here and then what I'm going to do is keep a bit of the information I'm going to right-click on this one and rename it I'm gonna keep the epsg code in here but I'm gonna call it ups G so I remember what that code is and then I'm going to give it a name here with G da 94 and this is the mga Zone 56 is what I'm looking for that was the previous was 55 Nexus 57 you can get any of these right here and if you're in Australia I would recommend just downloading all eight of these and then somewhere in here I'm actually gonna say projections file I'll explain that a little later why I call this why I've actually put that in the name of the file so with that I've now got my projection file in there let's have a look at this and see what's actually in the projection file it actually has all this information in it including what you're going to want to see at the end to check that you're in the right unit system in our case we're in meters and it needs to have a false easting and a false and northing in it now I think I'll just deviate just a bit and do and explain a little bit about projection files just because it's actually absolutely critical to understand how spherical coordinates get projected out into a 2d plane now there are some people who explain this much better than I can I do recommend just I hope I'll put a link to this in the YouTube description but just Google why all maps are wrong right here and watch these guys this video it just explains how over the centuries everybody who's been trying to make maps has always struggled with this trying to take spherical coordinates and put them onto a flat plane now I don't know if I can use these little tips like I do in a classroom setting here on the video but I'll try my best in a classroom setting what I typically do is take a glass fruit bowl or whatever I've got in the course and I put it over the projector that might be sitting on a table and what we'll do is we'll take this glass fruit bowl and let's say I draw Australia on it with a whiteboard marker here so I'll draw Australia on this and then what I'll do is just hold this thing up and we'll shine a light on it let's say the light comes right from the center so I'm shining through and putting this over the camera so there's Australia right there it's in spherical coordinates and I'm going to take this little light and I'm going to shine it up against the wall now on the wall you will see then Australia show and it shows up then on the wall if I trace that on the wall I would be taking a curved surface projecting it out to a flat surface I would have a zero zero coordinate I would have an X in the y-direction and with a projector you'll actually see the pixelation that happens and where you can actually you know you could assign a spacing or a scale to each of the pixels that you see on the wall but it's a flat surface now every six degrees we rotated so I'm going a little rotated chair here if I move around and I'm six degrees off in six degrees off I could take this wall and or take this screen and I could still project through from this projector out onto this flat screen now the farther I get away from it obviously the more warped it's going to get and once you get 90 degrees off you're not going to be able to see it at all so you can actually reproduction systems between different zones but you can't go too far it's going to get warped very quickly so that's just a little anecdote that I use in class again watch that video why all world maps are wrong and you might get a better idea for what a projection file is used for so with our terrain data and our projection file downloaded we're ready to go we're ready to start a new hec-ras project before we go too much further I guess I did want to mention a little bit about the schematic of Hecker as and where we are in this process in the end we're going to combine flow files with geometry files and we're going to combine them together into plan files overarching all of those is the head grass prj file right there that's the heck grass project that we're gonna set up now and we're gonna pull some maps in into res mapper before we get into any of this and that's where we'll be when we end this video we won't have any of these things set up but at least we'll be at the point where we'll be able to start setting those up so the last thing I need to do here before we dive in and make our new project is to move my terrain file into the terrain subfolder so I'm going to take this one that I just renamed to the Brisbane River Brookfield 5 meter GSA dot if that's your grid digital elevation model and I'm gonna move this over into my new folder and the subfolder that I've created they're called Brisbane and I'll put that under the terrain directory and now I've got a terrain full file and I've got a projection file those two files need to be in there before I go any further I do recommend putting this any folder that you're working on under quick access will just pin that right there to my quick access and then I'll be able to see Brisbane every time keep in mind heck grass does not recognize any windows shortcuts and you're going to need to browse right to the folder that's why I like to keep it in the C Drive and not under your downloads or documents where you have to go to C Drive users your username windows shortcuts and all that I just like to go straight under the C Drive if you're able to so now we're ready to go ahead and start a brand new project in ed grass so you start with file new project and under the new project again like I said it can get down here into the user shortcuts but I'd like to just go right here to C Drive Brisbane and make sure you see all seven of the folders that you just created it might default you up here to a onedrive folder that's gonna mess you up later on make sure you're in the same folder where you've just placed all these subfolders and I'm gonna make a new project here and we're go ahead and call this one Brisbane River and keep in mind that it won't recognize spaces as it tries to populate your file name but they don't have to be the same you can have a lengthier title here Brisbane River tutorial model and the file name does not have to match so I'm just gonna call the file name Brisbane make sure that this name right here makes sense to you and will make sense to you forever more because it's going to get replicated hundreds maybe thousands of times with different file extensions and changing it later on it's going to be a pain so don't call it something that's not going to make sense that you won't be proud to show it to a client or a stakeholder later on changing it around afterwards is a pain you can change the title easily but not the file name I'll say ok and it's gonna ask me this question do I want to be in SI units yes I do and it tells me where it's going to put the prj file so with that I've now got a project title and a project file name the next thing I'm going to do is open up brass mapper first thing I'm going to do with razz mapper open is set my projection so under tools set projection for the project I can go ahead and grab the prj file now I'm gonna make a bit of a mistake here you'll see that I did this on purpose this error why did I get that error well unfortunately there's this reluctance to change the PRT extension that's the same as the ESRI projection files so if I wanted to do it correctly I have to go into my projection subfolder there will be a single projection file there that I can grab and make sure that you see again the units the false easting and false northing this is my projection data there's an unfortunate coincidence that the hec-ras project files the prj files are the same file extension as ESRI shapefile prj files I hope they change that someday but it doesn't seem very likely so for now it's very tough to keep those separated which is why I like to keep my projection file in its own subfolder so that I don't get it mixed up with hec-ras project files now another little glitch if you're in SI units you don't want to make sure that you change your unit systems to meters here changing it later on can be a bit of a if you're in Europe you might want to use this alternate head grass raster warping method sometimes that'll help line things up and I'll show you later on where we get to a point of checking that and making sure that it's working out right so you say okay and nothing has changed but it's now projected if you didn't have a projection set and we tried to add a terrain file it would prompt you to either add one then or to use the encoded projection file which a geo TIFF might have embedded inside of it and you can do that as well so it will ask you for an SRS which is the spatial reference system and if you get that prompt to go ahead and do that so what we're gonna do now is right-click on terrains create a new raster and now a Raz terrain is not a new terrain like it says here new terrain layer you're not creating this from scratch what that means is you don't yet have an HD F file HD F is the hierarchal data format you're going to need to have a third-party viewer if you want to dive into these not many people need to get into the guts of this but that's how at grass stores most of its data for a 2d model and for any of the raster Raz map or data again if you hadn't set the spatial reference system you would be able to do it here we have this plus button here where I can now grab any file format if you look in the head grass manual under the help 2d modeling user manual in Appendix B you'll see about 80 different formats of raster grid data that heck grass is going to be able to read as terrain data only three of which will show up right now if you want to see something that's not in one of these formats you'll have to use the drop-down Grande raster data star dot star so we're going to go into dr. rain data I've got it set up as a geo TIFF so I'm going to actually be able to recognize it with these first three file extensions and I'll go ahead and say open now I could open multiple files and if you watch our videos on putting manipulating terrain data and modifying terrain data you'll see how we stack some of these up in our case we only have one I do recommend hitting info and making sure that you can see what the encoded data sets are inside of this one it's got it'll tell you what the the mga zone is and it'll also tell you what the resolution is just confirm that that's what you want to do I don't recommend using this one if you're stacking data that's different resolutions on top of each other but if you're tiled like that 844 tile set that I could have downloaded and that I've done before to merge together you can go ahead and click that button and it'll make a single raster image out of it or rest or to rain out of it now I could put multiple files in here and stack them up or down with this hierarchy remember this is a visual hierarchy not like our core to flow or other systems where it's in order of processing and the last thing you see is the one that gets the highest hierarchy a hierarchical priority this is visual so whatever is on top gets the highest priority that's that doesn't mean on top elevation wise that just means on top in terms of what gets priority over the no data use so here I've got a file name and I've seen a lot of models where people just keep this as terrain and then the next one will be terrain one and terrain two I highly recommend clicking on this folder button going into it's the terrain subfolder where we've already got our terrain and then you can give it a name here in our case it's going to already start defaulting to the name of the tiff file that's in there but this is going to get a hdf file extension so and what I actually want to do on this case so yes I've pulled this in but I want to actually specify here that this is the existing condition so when I put in brookfield this Brookfield's data I'm gonna actually say existing here so that I can differentiate that from any proposed condition terrain that I put in so now I've got this bit of a longer file filename here than I had before but that's going to allow me to differentiate between anything else that I might add to this folder later on before I hit create I did want to show you this rounding precision because we will open up a couple of these ones and show you the guts of what's inside of a TEM in a minute here and this will tell you I guess in binary format how much precision you're gonna have on the values that are in here so when I hit create it's gonna walk through a process here and sometimes this can take 30 seconds sometimes this can take 30 minutes sometimes it can take hours depending on how big your terrain file is in our case we're gonna just watch this for a minute here it should be done in just a second it's ours took 20 seconds and I want to open up you know you see some nice colorful image here but I want to just show you what jerez has just done with these files as well because it's important to understand this so when I go into the brisbane folder and again i have my head grass project now as a prj file I still have my prj file here which is my s reformat projection file but now under terrain I've got some new files here and what it is done and this is important to remember because once you get many many terrain files you may want to clean this out every once in a while and only use the ones that that you need this Brisbane River TIFF file that I've downloaded I no longer need that one for this model it has actually recreated this one here with another TIFF file and it has the name of the original so that you remember where it came from with a dot separating it from the name of the HDF file that you've given it this is a tiff file right here it has also made an HD F file which is going to store some of the data that grass needs to reference this and then the VRT file which as I understand gives it some information about the extents and the hierarchy and which for which files to stitch together here in our case we've just got one and it's orthogonal and so it's it's a fairly simple one you might have a file stitched together a terrain surface stitched together from multiple sources and you'll have many many files that all come together linked with a single V RT and HD F with multiple TIFF files in the background now before we get into interrogating this and seeing do we have good data I didn't want to just cover a little bit about the availability of data or the the acceptable formats or data under terrains here if I wanted to create a new raster ain and again now that I've got one I could hit the add existing and under terrain I actually see the HDF file if you've already done it once then you can go to add existing anytime you're doing a new one from scratch you need to hit create new so when I do this and I hit create new if I wanted to add a terrain surface and look here under this format and say I wanted to grab a tin or some sort of vector format or a point cloud you're not going to be able to work with that sort of data so a lot of times your survey data might come through as vector data like a trying a set of triangles or some other surface you're not going to be able to work with those at least not yet as far as I know what you need is a raster grid digital elevation model and I'll show you what these look like I'll open up a couple of these in notepad here and just show you what it actually looks like what we've got in a raster grid digital elevation model file and again this is the format we could have selected in a couple of the different data sources allow you to choose between a SCS that's an ASCII text file versus geo Tiff's or other format what we've got in our ASCII file here is a number of columns a number of rows the coordinates of the upper-left pixels using the projection that we've assigned and then a cell size that's your scale along with the node data value if you don't have this header data you're not going to be able to use it in R as mapper so what I can tell from this one already this is a two kilometer by two kilometer tile that has a specific corner it's see that it's a zero zero and these would line up exactly with the next tile over which would be another two by two kilometer grid and then it would have the next coordinates over you can actually edit these in in ASCII format and just close this and you would actually be moving this thing around or you could rescale it if you needed to when it sees this negative nine nine nine right here every time it sees that value it's not going to be negative ten thousand meters below sea level as an elevation it's going to ignore that and see right through it to the next terrain surface down in the hierarchy or if it's just no data watch out you're not going to be able to put a 2d area over the top of it so that's why I like to take the 30 meter resolution data and just take any areas where I've got missing data or no data values and just put that underneath of it in the hierarchy so at least I've got some data there now this one looks pretty clean but here I'll show you another one where it's not really organized quite as nicely and the no data values in some programs I think this comes out of arc go all the way out to the design cube the maximum extents of your design cube and they take that so this one's got some values in it it's got no data values you can see that the no data value right here has got this big number well very big negative number and every time it sees that it's gonna see right through it but then even the numbers themselves if you look at this I mean how much resolution is in there and how much wasted file sizes there if these are in meters there's your millimeters you know we're out past the nano meter that's really not going to be necessary which is why you can take sometimes very large files that come from other programs and when you pull them into a grass if you use the default one over 128 sometimes it shrinks them down in other cases it might add something to it but you can change it up and down depending on the resolution that you need in our case for this one that's perfectly fine to the millimeter you know we're not going to be able to be that accurate with our hydraulic modeling anyway so you might have some data that came from a surveyor that's in a irregular grid so you might they might have skipped some points because of some brake lines you know they might have coated in a roadway surface or an edge of pavement and because it was flat they just skipped a bunch of points and it's gonna fill it in with these triangles if you have the brake lines so that's an irregular grid that's a tin you can't work with that heck R as in raspberry a regular point cloud and convert that if you're going to have a raster grid de M format it has to have already been converted into something that's got a regular orthogonal shape to it where every one of these points is laid out in a regular grid spacing so you don't get to skip any grits here now once you dive into it and zoom in on it you might see that heck rads has displayed it as a tin but again it's based on these regular point networks so that's what we're stuck with right here and at least for the meantime and I'll show you just real quick on the heck Raz help menu where you can see the formats that are acceptable we open up here on their help and go to the 2d modeling user manual and if you just zoom to scroll to the end you'll see down here in appendix B you've got all of these different file formats that recognized and again she hoped if being one of the most common ones ASCII files as well what you'll notice here though is some of the ones are not listed I don't know why they haven't put this in alphabetical order but if you're using civil3d or even 12d some of these packages can export a dot de em file you have to choose the resolution but when they export the dot de m-files sometimes that comes through as ASCII text and it doesn't tell you that that's one of the accepted formats but when you add it it'll come in just fine because it is ASCII text typically I recommend asking the surveyor for this if you cinch any foul and do his double translation songs lately on Google Translate it's kind of the same thing a lot of times you'll have a surveyor who starts out with some surface cuts it into contours and then people will use the contour to raster or topo to raster command to turn it into a raster don't do that if you can help it at all here's a quick example I guess some that I wanted to show you then you know if you had a surface and you cut contours off of it and then you use these contours to go back and make a surface that you're going to display as a regular raster grid you're going to miss everything that was in between those contours which you may have already had picked up from your surveyor so you're going to be missing some of the data and what you get out of it having started with the surface go on into the contours and then come back to a surface that's a double translation and you'll end up with all sorts of missing resolution and again just to give you a visual of this we'll do this in the class sometimes we'll throw something into the English to Albanian translator and then bring it back from Albanian in English and you see that you get all sorts of messed up phrases when you do a double translate so I try that one just for fun now again just to drive this point in to make sure that we know what's what we've got what we're working with I always use these kid toys here in the classes if I'm trying to generate a terrain surface and say these are mountain ridge lines and rivers going through there this is what we're left with okay these are individual pixels now I can't use a point cloud this has to have the header data in it as well heck grass is only going to store X&Y coordinates or the the de M format will only store the XY coordinates of this particular pixel the rest of these are just Z values Z values here in Australia we know the number of rows and columns and so that tells it when to start repeating these but the rest of it like we saw in that asketh while it's just a list of elevations you only have a single X and a single Y data value listed all the rest of these values right here these are only Z values there's your only X and your only Y in the whole file so it ends up being a fairly efficient format even though it's you know repeating some information in between areas where it's absolutely flat you're gonna have a value everywhere and we'll see that in this particular terrain data set we're gonna see some areas where it is absolutely flat so let's check our data and just make sure that the terrain data is good enough for us to be able to use and in order to do that we're just going to cut a couple of cross sections and see what we're looking at now if I wanted to model say a development along this tributary maybe I'm interested in how wide the floodplain might be and whether I've got this model correctly might depend on whether I've got enough resolution in my channel now let's zoom in on this and see what we're looking at just just make sure that we've got the resolution we need you see these kind of tiles going on here yes I've got this thing at a 5 meter resolution if I click on my measure tool and come across here I've got a 5 meter by 5 meter pixel here and like I showed you in that previous model we've got one point for each one of these pixels and HEK grass has displayed it with some triangulation that said all it has is a single value a single elevation value for each of these points but you see this tiling right here you can tell that this has been sampled down from the 30 by 30 meter data set so this is not going to be as accurate as you might think but let's cut a cross-section here and see if I was putting in a development right there you know am I going to be able to reflect this channel properly so what you're going to do is double click at the end of your measure tool and you get this map menu that allows you to plot the terrain profile is this enough resolution I don't it depends on what you're looking for to me this looks and looks fairly good but you may want to go out there and drown truth it and figure out you know did it properly reflect the channel banks you know the slope of the channel banks or did it miss it because it was shot from space or from an airplane or from a drone you know did it filter out the vegetation properly did it get both imagery in there let's have a look at the Brisbane River itself if I'm trying to map this floodplain for the Brisbane River and I come across and do a cross-section like this what you'll notice when I plot the terrain profile it's absolutely flat now how many riverbeds actually look like that so we know by looking at this well the lidar didn't shoot through the water where they've gone in and replaced it and one of our exercises that we go through is to actually have the bitumen tree back into the Brisbane River in both our 1d and 2d modeling classes we go and and modify the terrain so that you can do that yourself so that's one thing that I like to check is just did you get in sufficient resolution out of your terrain data if at all possible ground truth it next thing I like to check is go into your map layers and I'm going to go ahead and add web imagery to see if I'm in the right place on the planet and make sure my projection is correct I like doing a hybrid in the beginning not necessarily four figures later on I'll use google satellite or Bing satellite but the hybrid at least will give you some points of interest and put the text on there for you so that you can see what you're looking at in our case I'll zoom out on this one just to show you once we click on this one you won't see anything underneath this so I turn it on turn it off it looks like it's in the right place but in order to see through it double click on your Google hybrid and let's scale down the transparency here a bit and that way you can see them both at the same time and see how those line up you know we could do a tighter check on that but it looks to me like we're in the right place if you see the Sahara desert or an ocean out here then you've got some issue with your projection file now this is relying on an internet connection to give me this Google hybrid view if wanted to keep looking like this and you don't want to rely on your internet connection and you want it to look that way you say you've presented this to appliance or a stake holder and you don't have their Wi-Fi password it's going to look like this and if you've set it up and you wanted it looking like this then you probably want to do some save views so say your project was right here if you go to surface water drop bid slash views it'll walk you through the process of doing this at multiple zoom levels I'll just do a quick one right now name this view right here we'll just call this gold Creek and that view now no matter what I do if i zoom out and then go back to this view it's gonna take me right back into this map frame so I'll double click on that and you can see it's just going to come right back to it I can do this at multiple views but once I'm saved here at this view I'm gonna go into this Google Hybrid and export the layer and I could do this as a JPEG in which case I'll get a world file jgw file I've got a tutorial online on how to adjust those if you needed to make a shift to it but we'll put this one here as a tiff for now and I'm gonna put this under aerial photos that's where I told you we store our static images I'm gonna give this a name Gold Creek aerial say something about the source Google and I'll hit save now what this is going to do is at my screen resolution export me a tiff file that has those same extents so now under my map layers I'm going to right click on it add an existing layer and then we're gonna go in here under aerial photos it won't see them yet you have to actually drag down as only Misty's shape files as existing layers until you get calm and raster files again you might have to go to other if it doesn't list them here but there's your Google image and again it comes through with no transparency that's a new thing that they've just added and so when I turn off my Google Hybrid right there and only have the terrain underneath it I could turn on this aerial which is now completely opaque scale it back and you can now see basically the same thing that we saw with the Google hybrid keep in mind though that when i zoom out it's not going to add anything else to this so when I turn off my Google Hybrid you won't see any terrain data behind it okay so I've only got it right here I'll turn that back off and show you the it's just to the zoom extents see that's just the views that I saved too so there's nothing outside of it and if you zoom in you'll notice it gets very pixelated so if I wanted to see this building right here and I wanted to turn on something that's going to show me a little more resolution I'd have to go back and do this again save another view here at this resolution and then you'll see that Google is going to be able to pyramid that and give you better resolution the next steps then after this is going to be setting up our geometries so what we'll do here then in our classes we'll go ahead and start with the geometry and we can add a 1d geometry to geometry get our structures built in but because this is the common point where we split off in each of the classes I wanted to make sure those videos out there for everybody to see one other thing I guess I would suggest being able to do from the very GetGo is make some profile lines and save shape files for them so there's three different ways to make shape files in res mapper and each of these is covered in our workshop document what you can do then under profile wise is delineate these using this plus button use the profile line tab to things I like people to be able to do from the very beginning is to be able to do a centerline you know a channel line right here I won't go all the way down through it but delineate anything that you've got for flow paths these will be useful for break lines later on you can save this and give it a name this will be Brisbane River CL and the next one I'll do is a cross section make sure you always get in the habit of delineating cross sections from left to right looking downstream and likewise River centralise get in the habit of delineating those from upstream to downstream so I'll do one here called a cross section and that later on we'll use these to interrogate our results so there's my cross section you can see it's get stationed or changed there here's my centerline now these once I've drawn them I can actually export these to a shapefile to other ways to make shape files in Arras mapper one is right here under map layers you can do create a new raster or generic layer it can be either point to polyline or polygon you can do the same thing here under features so you can create a new layer point polygon or polyline and this one will show shove it right under a new directory called features this one will put it under your master directory which I don't really like to do that it gets lost then I like to keep him here under feature so this is my preferred way to make shape files anything that you've delineate 'add external can also be added here if you pulled it into GIS already if you've delineated it or got arc Hydra or something doing flow paths and watershed or catchment divides you can actually add all those in so I do want to walk through the process of at least building one shapefile just so everyone's familiar with the editing tools in this case we'll just call it a catchments or a watershed and I'm going to go ahead and make a polygon shapefile using this add new features button which it defaults to now you know we could be very precise about this I'm just going to just do it generally to show you how we're gonna set these things up going forward as I just start delineating around if I did get out to the outside of the watershed here then when I get to the final point I'll just double click and that gives me a shape what I do want everybody to be familiar with and we will delineate things for each of these classes separately you know center lines for the 1d class with cross-sections 2d areas and break lines in the 2d courses anything that you edit and delineate indecorous in brass mapper now you'll get these editing tools and so with those though the one thing I wanted to make sure that everybody understands is how to edit the vertices and how to add things what you're going to do is go to the second toolbar right here and double click on the feature in that case you can add vertices you can move them around you can delete them just get familiar with those before we start our classes and that way we'll be up to speed and then whenever you're done editing you can stop editing and save those edits if you like or discover them if you don't like them now another thing I wanted to make sure everybody can do is to edit the properties of any of these layers go ahead and double click on any of these things here play around with each of these the terrain surface symbol settings and all these things that you can do here one thing I really like is this update per screen which allows you then to see all of the resolution when you zoom in it just gives you even more contrast between the higher elevations and the lower elevations so play around with each of those settings add the contours and the hillshade if you highlight these and then use your middle mouse button in some cases you'll be able to scroll up and down through these and see visually how these are going to look at different intervals now one last thing I wanted to cover is something I forgot to mention in the very beginning right here this description never ever leave this blank in the manual I list a couple of things that you might want to include there for instance the project purpose may be your name and contact info the the date that it was put together give us some information about this the reviewer will thank you for it later on feel free to go back I know some people have said I speak too fast or I cover too much information hopefully a YouTube format allows you to stop and pause and watch things again if I have covered these things a little too quickly and likewise if I've gone too slow for you you can just scroll ahead so with that then just to summarize where we're at with this thing I'll pull our somewhat ambitious agenda here and just make sure that we've covered everything so we downloaded hec-ras installed it son grabbed our terrain files and projections set up a folder structure start of the new head grass project made the new unit systems in our case it was s I opened up as mapper to set the projection pulled some terrain in added web and static imagery and then check the terrain to make sure it was good now you are ready to model so again I probably should have posted something like this from the very big because this is an exercise where we go through multiple times in every single class and that way if it's out there I can just tell people this is required watching beforehand that way if you already know this you're not wasting your time waiting for everybody else to do it and if you don't know it yet then you only need to do it once and then we're ready to go because once we've got this terrain in here this is the sample project that we use for each of our online courses so if you are signed up for one of those I look forward to interacting with you live in these courses sharing screens and doing the things we're able to do that way I do hope I get a chance to meet some of your face to face as well as we do our tours worldwide for courses covering any aspect of hydrologic or hydraulic modeling so please subscribe to our YouTube channel or if you also go to surface water not slash subscribe you'll get newsletters covering new tips and tricks how to do things in heck grass and other software and especially GIS software that's useful in being able to interrogate the results and set up your initial files with that I'll go ahead and sign off we'll see you next time thanks

Channel: The RAS Solution

Views: 39,211

Keywords: HEC-RAS, Ras Mapper, Download, Install

Id: BUjF_MGcxYQ

Length: 51min 21sec (3081 seconds)

Published: Mon Sep 23 2019