Flood Inundation Mapping Using Remote Sensing DEMs and HEC-RAS (for data-limited areas)- Part2

okay let's go to the next uh part of this uh topic first of all you should open your H and create a project as I mentioned in the uh first uh part of this course you should go to the file menu and select new project and in the desire or your uh selected location I will go to desktop paper and in this part uh I will create a new folder he model and the title is blog inundation mapping or other name let me to delete this word and select okay okay uh I want to import UTM them which is in metric system and therefore you should use SI unit for your project if you use uh us customary or futi or inch or other uh Dimension you should select your suitable Dimension and coordinate system okay uh in this uh section uh we want uh to use G ha for extraction of uh cross-section we want we don't want to use uh GIS or hexas extension for this issue because you know heas in new newer versions uh provide an environment with the name of GIS tools and in this environment you can uh use uh the tools uh that help that help you to create river banks uh cross-section structure and other related information for a Riv okay uh however in G environment you can use hexor and using this extension you can create a stream Center Line Bank line flath cut line bridge and other information uh related to the to a real River okay uh we don't want to use this extension however if we don't have enough time I will uh come back and explain how can we use hexas for our purpose can however I I think ha is the most suitable for this task uh I will go to the gis tools and use grass mapper environment for this issue okay let's to wait a little bit okay H you know Ras mapper is one of the most important parts of the newer version of HR and in the old version you don't see this uh environment because this environment is added to the he after I think the version of five okay before importing our downloaded them you should Define uh the coordinate system of your project in R mapper okay in tools uh menu you should select set projection for project okay uh there is need a e projection file that defines the location or the extent of your uh uh uh projects okay uh how can we create this file okay don't worry there are a there are a very simple uh way to access to prg file uh uh you can use special reference. org website to download the pg. prg file okay as I mentioned uh in the previous uh section we use the UTM Zone 39n therefore in this search section you should search exactly this uh name WS is the datum of our data set and UTM is the coordinate system and the location of our project press search okay in this uh page you can see the different projection system some for carala some for Iran some for uh Yemen and other parts of the world uh and in this section I will download this name I click on on epsg okay in the second page you can see different coordinate system format for example Json gml e prg USG and different uh projection uh file format for different software and for different environments uh we don't need to download all of them you should only download the P prg file okay uh you should type the best coordinate system or the the best pro file for your case study okay in this papers I will download that prg file which contains the coordinate system of that zone okay just download it completely and in as projection file you should go and upload the downloaded file I will select this file with prg okay you know the coordinate system and the zone and the uh I mean the unit the meter and other information of the projection for 39 for zone of 39 select apply and then okay if you don't do this task uh you can use the uh web imagery in your ha project because when you select the the projection system or I mean a specific uh coordinate system uh Google SS or other online uh Maps uh will be downloaded automatically for your case study okay the next or the next or second steps uh is importing the downloaded and extracted DS okay select NE trains and and input train file Select Plus and go to the my allow them you know I converted the downloaded them to UTM therefore I select my all UTM and you know there are different files with with ADF and you should select the file with the higher volume okay I select Ed f with the higher volume however you can use T FLT and ADF format into hress I select open and you know the model automatically create a folder with the name of train and the output name is train. hdf you know he use these uh Tools in order to decrease the volume of imported dims you know in uh large or in large rivers the volume of a river maybe is about 50 uh 500 megabytes or one gigabyt and handling this uh volume of them for is completely hard therefore they uh they provided or developed a tools for compressing the volume of your dim and converted to that hdf I mean high density file for example if your uh imported them uh has a 100 megabyte volume these tools can decrease the volume into about uh maybe 10 megabyte or 20 megabyte which is completely suitable for H okay I will uh press on create button and after a little bit second the D is uploaded or imported to the ha you know the model is imported the ADF D and convert it to hdf okay you know your Dam uh from the upper to the down is this is the end of the reverse and downstream and this is the upper stream of our case study okay we imported uh the D into ha and the next step is to create a stream Center Line and Banks and other information excuse me for this connection of my mouse okay in order to start Crea River uh River Center Line you should right click on geometric and select manage excuse me add a new geometry okay in this section you should type A a name for your geometry I will enter the my Gil okay and press okay and you know uh the my Jo geometry is created in this section you should start to manipulate or to complete the required layers one of the most important layers you should must be you should uh start to create is the River Center Line okay I will check the rivers and right click on reverse icon and select edit geometry and you know this is a little bit like to editor extension in GIS environment and this pen start and using this pen you can start to create Center Line okay I start to digit from the downstream and through the center line you can zoom into the them and start to digit you know this part is the center line of the river and in order to go through you can right click okay this is the center line and I think the low elevation of the river however after Digi you can modify uh the center line in the geometry data window okay and at the end of the point I you should double click and select a river name and Rich name okay in the river name I will select SOS and in reach name main reach or op or other any related names okay right click and stop editing okay congratulation you you have done it completely the next step is to create Bank line select Bank line check that right click and select edit geometry okay uh you can see easily the banks of this River and I can start to digit from the bank okay this part I think is the best location for okay let me to click faster and then double click at the end of the digit point and come back to the opposite room and start to uh create the right Bank you know the flow uh is Flowing from the up stream to down stream and this area is the uh left uh left bang and this area is the right band and this is the main Channel okay we should create and digit the right Bank using Dam okay don't worry about rough Digi thing you can completely edit the location of banks in the geometry window okay I don't want to increase the time of this video and try to digit fastly okay this layer is completely created okay right click on this ler and select stop editing and select yes to save edits uh for my Jo Okay the third slope is creating flath I select flath you know phath uh defining phath means that that means uh when fla is surface to the flat plane uh it defines the direction of uh uh flowing of a flood okay we right click on this layer again and select edit geometry and start to digit flow pass uh you should be noted uh when you are Digi in FL pass you don't you shouldn't cross the banks or go out after them you should completely digit between them and Banks okay I start completely parallel to the banks it does not so important for modeling and you should only digit between Bank lines and [Music] inms okay this is for left FL plane and this is for right flat plane okay start so digit come [Music] on okay that's completed and right click on that and stop editing select yes button and the third step is completed or finished the fourth step is to creating cross-section okay you should select uh cross-section options in magenta color and right click on that and select edit geometry and start to create cross-section from the left side to right side okay I start to uh create cross-section from left side to the uh right side and don't exit from the DM boundary and try to cover all flow pass Banks and stream Center line files okay you should try to uh digit completely perpendicular to the uh Center Line you can use like you shouldn't uh digit like this because the angle is more than 90° you should uh digit to create 90° angle between cross-section and reverse center line for example when I uh digit this cross-section you can see the angle between the reverse Center Line and cross-section is about 90 M try to uh create cross-section if you see uh the river have a wide uh width and when River start to uh decreasing you should uh create several cross-section the more cross-section the better representation of river geometry for for inundation mapping okay I start okay let me to create more crosssection from left side to the right side okay it doesn't matter to create cross-section between to cross-section again the model automatically create rever station for each crosssection and you don't need to go head press and start to uh create rever station okay I think this is good for this River okay justi this okay as you can see we can easily use C for uh creation or extraction of rever geometry without needing to GIS or other similar environments okay after finishing the digit process you you should right click on this uh layer and S stop editing press yes to save your project okay isolate save and we don't have uh I mean we don't need to Ras mapper in this part therefore I should close this and you should go to the view geometric data window and in file menu select open geometric data and select my Jo which is created in Ras mapper okay I select okay wow congratulation you can easily imported your DM and cross-sections into geomet Data if you don't see your train data or your dim in Geometry data you should go to the select layers to V in background and check the plot train options you know when I check and uncheck you can see the D in in the background okay select the river and river Center Line and select XY Z plot okay you can see a natural River with different cross-section you can go to the cross-sections and see the shape of crosssections the station elevation data sets the lob Channel R OB and the Manning roughness should be calculated for each part of a cross-section Left Bank right bank and I mean you don't need to manually processes to complete this section the model automatically uh created these values you should only compute or enter Manning for uh different parts of different parts of uh cross-section you can go different between different cross-sections and if you see some station points need to modification you can just only click on jump to graphical cross-section editor and using by hand and select the and change the location of Banks and go to uh to other section you can change the location however they are completely suitable okay okay okay we don't need to check all cross-section I think they are completely okay save geometry okay in this uh part you should uh compute or enter the Manning roughness coefficient for right and left over Banks and Main channel for each cross-section okay in this example we should use a uniform runoff coefficient for all cross-section uh please go to the tables menu in geometric data and select Manning values okay you can uh as you know there are 31 cross-section and you should enter uh maning roughness coefficient for each cross-section n uh one is related to Left Bank N2 uh related to main Channel and N three is related to uh right bank and for each crosssection you can enter a unique roughness coefficient okay let me assume that for 14 cross-section we want to use this value for Left Bank for main Channel and [Music] for right Bank however in the next section I will explain about a suitable method for calculation of runoff uh maning roughness coefficient for a specific Riv uh and I will talk about uh that but in this section I will use we will use uh these values for flood ntion mapping and for the rest cross-section you should use another value okay don't worry we can we should uh estimate these values easily for each River using standards and uh suitable methods okay okay when you come back to the crosssections and go to the uh lob Channel and R O you can see the run uh maning roughness coefficient okay let me close select data you can right click on this and see the profile plot okay let me right click and uncheck the left and right okay uh you know this Riv at the uper stream is uh has a higher slop and the down down slope has a lower slope okay save uh go to the edit a steady geometry file okay in this example I want to check the water surface profile and other hydraulic properties for different uh for three uh discharge values okay enter three number and apply data and you can change the name of pallot to better representation in the output results section okay q q with the return period of 10 Q with the return period of 25 and return Peri of of 100 okay the value of this chars for this river is about 150 400 and 1,5 and 500 okay apply and select file and save this file in the folder follow data or FL data okay you know the next step is to define the boundary uh conditions value select reach boundary conditions and you know for upam and down stream you should select suitable boundary condition uh you know there are uh four different boundary condition types but you know in most uh natural Rivers we don't have uh enough observe data set for running ha crft especially rating curve or nonwater Surface uh that based on observe water surface and observe discharge value therefore we should use normal depths for bonding condition uh for both upstream and down stream I select normal depth you know normal depth is not the depth it's the SL Loop that leads to normal depth in this uh boundary condition the model assumes that there are uniform FL L and the water surface slop and the bed Loop is uh completely or almost equals okay therefore we need to enter the bed Loop okay let me to come back to main window and view select View profy and press uh control in your keyboard and start to digit for about three or four cross-section I select the start and the end click and leave the control and after uh leaving the control button you can see this figure in this uh figure you can uh use Dy per DX for B slop okay uh I should copy this value go to the boundary condition and in the uper stream select normal deps and enter this value for boundary condition okay and go back to the uh down stream however in this uh area we don't have opposite profile and therefore you should select higher elevation and connect to the end of the rivers click and leave the control button okay you know uh the down stream of river in this case have a smaller uh SL slop and I click right click and select copy go to the boundary condition and in down stream select normal depth and enter this low slope value for up stream this is value and for down stream is the lower slope however you should be noted that when you uh want to define the value of uh this s Loop you should select only three or four uh cross-section of the up stream and down stream okay in the file and select flow data and you can run the model before running the model it should be noted that in this course I've tried uh to represent the newest uh method uh for estimation of uh flood discharge for different uh return periods and in the next uh part of this uh valuable course I will you will learn how can you use the row data set row I mean uh flow discharge in hromic station and converted that to uh flood this chart with different return period uh we will use flood frequency analysis to calculate the value of different flows with different uh return period you know in flood inundation mapping and flood protection flood protection studed you don't need a you don't need specific discharge with different with specific uh return per period for example in most River engineering projects we use uh discharge with different with return period of 50 or 100 perod or 25 years for modeling okay don't worry we will investigate how can we calculate the the value of these written periods okay the model is completely ready to run okay in the Run menu I select stud FL analysis save plan allos okay and in the ID you should select all okay check the mix to model select automatically the super critical or subcritical conditions through the rivers select the bounding mapping in order to flood ination mapping and in the plan description you can use uh simple Tes for your projects okay compute press the compute button and way to running the model OKAY Model start to running successfully and start to storing the results okay after uh 17 second the model is R okay you you can go to the RAS mapper and uh see the flat plane extends and other related hydraulic parameters and also you can use this window for flood hydraulic properties okay you can select line and symbols and change the color and the line settings for example I select this wids and this line magenta without any symbol and uh water surface of uh Q 100 maybe green without any symbol and therefore ground B Loop okay you can see a beautiful cross-section or water surface through the river for different uh with different uh return periods as I mentioned before you can uh go to the file and select uh copy to cliport and go and go to the V or office environment and paste in that area or copy to kort and for example select a paint or other related environment for pictures and save the output as pictures okay select paste and save the button and select the name profiles save also you can uh convert or export this uh output to AutoCAD environments as dxf or DWG file format okay for example in the cross-sectional view you can use and see the water surface profile right click and select zoom and go deeply to the picture Okay in this picture you can right click and select line and symbol and change the line wids symbol and other related settings okay like this also in file menu you can copy to kboard or print multiple uh write dxf file and open these files your or this output in AutoCAD environment okay let me to stop this video in this part and in the next part we should uh investigate or we will show you the differ output of uh heas uh hydraulic properties okay

Channel: HydroAI

Views: 8,237

Keywords: HydroAi, Azizian, Artificial Intelligence, Hydrology, flood inundation mapping, HEC-RAS, Flood Hazard Mapping, Flood management, river engineering, Flood control, Flood Damage, Remote sensing, Digital elevation models, DEM, SRTM, ALOS, ASTER, Hydraulic moeling

Id: 76nGnh-geMk

Length: 38min 40sec (2320 seconds)

Published: Thu Dec 07 2023