Generating River Geometry data to HEC_RAS by ArcGIS from DEM 

Thanks for your Comment Wellington Andrade. I will try to upload other video tutorials relevant.

SAMSEIHA UK Hi sir I keep getting the same result. The problem is that the cross section is not getting the ground points and bank points. It just so happened that i found you on facebook from a comment on the same video so took the opportunity and sent in your messenger the picture of my result. hehe

Make sure you have the right Unit (After projected it's in Meter)

Thank u. I figured it out. Ras layers were in a different projected system.

Thank for your kind interest. I try to upload other videos regarding to HEC-RAS model.

TO project Raster Coordinates systems, U have to firstly Define projection to WGS, then project raster to your specific area. In raster projection, you may check Cell size. Good Luck

2D model in HEC-RAS is based on the DEM, for the river cross section is used to perform in 1D

I guess we can but you have to overlay it on a dem so that you can start

Well JJ Nitro, Thank for kind interest and feeding back. Regarding to the bank, there are serval problem is considered: - Properly create Bankline from Upstream to Down stream, and from Left to Right. - Compatibility of GIS and HEC-GeoRAS U can add bank point directly in HEC-RAS using Graphical Cross Section Editor. Best

SAMSEIHA UK Thank you kind sir for the reply! I am using ArcGIS 10.3 and georas extensions also 10.3. I will try what you said and I will update of my results. Have a good day sir.

Cool, enjoy!

@j J Nitro I have same problem. How can I solve this?

Same problem here !

u have to change the regional configuration of ur computer so that the decimal symbole change to "." insted of "," and regenerate ur TIN

It is a small river, can I use my river centerline as flowpath channel and bank lines as left and right flowpaths?

Well, the flowpath is a tool need to be defined for your flow direction. Somehow, Flowpath and river centerline are situated at the same line, but flowpath is need to be set for center flow and as well as left and right flow path.

Okay, I see what I am doing wrong. I am dealing with a canal, not a natural river. So I don't have overbank flow lines. The bank lines are the same as flow lines. Should I draw bank lines or flow lines?

So far If you tend to use HEC-GeoRAS to extract river geometry to HEC-RAS, you have to do all the thing by step.

Hi Wellington, Thank for your interesting on my Channel. Please try to defined one by one to each componenet and let see it.

Thank you for your quick response. I just solved the problem together with my boss. Because I drew the Polylines in Google Earth they had a Z Value already. I just converted them into a 2d Polyline without Z values and then it started to work out fine. Now I have the problem, that when I try to export the files, there is a data error which I fixed by putting all the files into a geodatabase. And Now the problem is that ArcGIS just crashes when it is finished with converting so now I am working on this issue.

Great you have solved it, Cheer.

Hello Teng Teu, Well, Pusat river is stretched from the upstream boundary where it's located at the high topography to the downstream connects to the lake. I am pretty sure that at the lower land, the DEM gives non-accuracy elevation to show you the river path. There are several ways can be done to determine your river center line, bank, and flow paths. Since now, google earth or google earth pro is available and free, thus you can have a draft drawing or sketching from the google earth as the layer file to your ArcGIS. The taken layers are kml format, then you can convert it to shape file. Finally you can stretch your river center line, bank, flowpath based on the layers imprted from google earth.

thanks bro,it's a great explaination.I will try to follow your advice to get it.many thanks again

Good Luck!!!

How about the data frame unit? Make sure it's in metric unit not decimal unit.

Kim Dolla thankyou for you quickly reply sir. Can i get u r email id for my future quarries.

1. First I loaded ASTER DEM in ArcGIS which was download from Earth Explore. 2. After that, I project Dem with project raster and changed the coordinates system into WGS_1984_UTM_Zone_44N 3. After that I went to RAS Geometry> layer setup > in GRID> Selected my Dem. 4. After that I went to RAS Geometry >Create RAS Layer> stream centerline > and project River into my coordinates system WGS_1984_UTM_Zone_44N. 5. After that edited RIVER >and went to >RIVER Attribute table and checked river length. It is showing in decimals. 6. I changed in Data frame properties, units as meters and my coordinates system as WGS_1984_UTM_Zone_44N but no use.

Hi, For adding the Terrain to the Ras Mapper, DEM file or any raster format is demanded for adding as a new terrain in the RAS Mapper. The format are .flt .tif .tiff etc.

You have to consider the Cell of your DEM with the width of your river network, i.e DEM 30 gives you 30m grid cell. If your river network is less than the width of the grid 30m, the cross-section sketched is straitly shown.

Thank you for your reply. I guess the map just detecting straight elevation on my location its because It is just a small canal. But my new problem is when I incorporate my datas, the Length That I Plot in georas (Create Layer) which is shape are not in meters, For instance, my Length Canal should be in 2000 meters but it shows it attribute shape layer is just 8 without unit, so when i Import it in hecras, it stays 8

Make sure you have project your raster data set in metric unit, for pre-processing you have to set your data frame in Metric as well. Cheer!

How can I do that? I'm sure I did what I have to do to change the units and coordinates to meter. but when I create layer through georass and plot centerline flowline etc. it still the same

My problem was solved! I convert my created layers from Georass to right coordinate system WGS_1984_UTM_Zone51N as well as its the main layer of arcgis and my TIN raster but when I Import it.. It crashes .. Im so unlucky :((

Hello, there are various sources to get DEM, but Earth Explore is also helpful

look for Alaska Vertex Facility

Thanks for your comment. Stay tuned to get more tutorial video concerning to Hydraulic model.