Easy HECRAS 1D Flood Modelling Tutorial : Steady Flow Analysis: HECGeoRAS not Required

is truly talking about 1D analysis necross let's get started so first of all we're going to create a new project for that go to file a new project and the desired location so let me name it uh analysis okay so it asks for the unit so right now I have SI units I'll select OK if you want to change the unit just go to options and unit system and select the one you require okay the next thing I want to do is I go to adjust tool and open the RAs mapper so the last mapper is the gis system within the hair Crush okay the first thing I want to do is set the projection for that I go to Project and set projection and here you select the projection file it's the one with the dot prz extension now this analysis is our our project file within a grass this is not the one the another one this project.prz it is our file so I open it so you can see the name of the projection system that is UTM for 44n okay and click ok now what I want to do is create a Terrain for that go to project and create new rust there in and click on this plus sign and select the damn file of your location okay I'm selecting it and clicking create okay let me close it now you can see the terrain file so if you have a very accurate terrain file then you can easily distinguish the river feature and it would be convenient to directly digitize but in this case I think it's quite difficult for me to distinguish the river right so what I do is to be more ah accurate I want to see the Google imagery so for that let me go to uh project and select add web imagery okay and select Google image sorry Google satellite and click on OK now check the map layers and you can see there you go here's our Google imagery and you can see the river over here so yes now we can these guys easily right okay so to start digitizing we have to define the geometry first so go to Geometry right click on it and select add new geometry so keep the name I'll give it a river and click on OK what I do is I want to edit the geometry click edit geometry so you can see many options right and right now I want to digitize the center line so while you are digitizing the center lines always go from the Upstream to Downstream right make sure you know the direction so right click on it okay it's already activated so I went to go through the center of the river not necessarily exact center but try to be uh as near as possible okay okay you can zoom in and zoom out as per your convenience here a bifurcation is occurring here we'll avoid it okay since we are in the beginning stage okay like this you keep on following the center line of the river and when you're done double click on it okay so River name you give it so for its River one okay Rich one said okay the next thing what I do is uh stop editing so it's a bit it's yes now you want to digitize the bank lines so go to bank lines edit geometry and start digitizing the bank same as the center lines okay not necessary to be exact Banks but you try to distinguish between the bank lines and slot plane as far as possible okay I'll do here okay and when I finish double clicking it okay similarly in the right hand side okay there this way okay again right click on it stop editing save it the next one is we need to ah this type the flow path right okay so for that ragging the flow path edit geometry and give a possible uh you know the float plane or the river okay so I am doing here here okay sinner in the other side okay there you go so let me stop it okay the next thing we want to do is create the cross sections line so for that we need to go to this edit geometry you can see the cross sections select it right click on it sorry and let's create cross-section line so for that you need to go from left to right always remember that while creating the cross section line you should start from left side of the river and move towards the right one so in our case it would from here to here and always remember that the lines should intersect all the lines center lines Bank lines and flow path lines they should all be intersected by the cross section lines okay this way you can see the station IDR automatically generated the same task could have been done from the geometric editor okay that is not necessary that it has to be done rust mapper if you feel convenient in geometric editor you can do that from here okay after you are done with it right click on it stop editing and save yes I want to save my rasmap file so save it okay let's close it now let's go to edit and geometric data now you can you know import the geometric data here so for that go to file and open Geometry data okay so here is our reverse geometry so select it and clicking ok you can see the terrain file and this reverse Interline the cross sections line okay the arrow is pointing towards the flow Direction okay I want to hide the background image for the moment so I go to here and then close okay it's easier now you can go to cross sections and you can see all the information here okay or different River stations the elevation values right you can check for it okay now the next thing I will do is insert the Mannings constant for that go to tables Manning Center K values so I want to for the time being I want to set the value 0.035 now you can supply the value as per the side conditions and I will provide you the link for the Charles Mannings constant right you can go and access from the description box below Okay click in ok so if you want to provide the Mannings and for all the stations for example if you are sure about the ah value of many ends for this particular point then you can individually provide say for example 0.025 or something like that if you find it so if you are sure about it then you can enter them accordingly otherwise the same value would be applicable okay so let's close it now I want to save the geometry okay since we are done with it the next step is we go to edit and steady flow data okay so we want to enter the number of profiles for the let's say we will take three and we want to change the name of the profile so go to options and edit profile names let us say it is for ah through your written period value the next one is 10 year and say the last one is for 50 year you can add as per requirement okay and I want to insert the value for example for two editing period it might be say 1000 or 10th year which might be 5000 and for 50 or it might be eight thousand just entering random values okay and I want to save it save flow data [Music] ok the next thing we want to do is run this TD flow analysis let's run it and Define the flow regime there is subcritical supercritically mixed I want to go for sub critical and float plane mapping okay but before that before that we need to make sure that the boundary condition has been applied so before Computing let's go to edit CD flow data there's a rich boundary condition so Upstream will be applying normal depth okay promise 0.001 or something like that Downstream it might be 0.00 25 or something like that okay I understanding some random values okay I'm clicking ok so file safe load data now we can run it so go to steady flow analysis and give some ID for example one one and click in compute now the simulation has started okay okay so it's completed let me close it and go to JS tool Ras mapper and for the moment let me uncheck the map layers uncheck the terrain layer geometry layer and go to results okay the difference between okay and you can see the changes okay you can see the value of the depth that's what 10 year written period okay

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Id: 0qHczo7jEbo

Length: 13min 2sec (782 seconds)

Published: Fri May 26 2023