3
votes
Interpreting ArcGIS flow accumulation tool results in urban areas
If your question is something like 'where can I expect puddling and flooding you will not achieve this with a flow accumulation surface. Flow accumulation is returning a new grid where each value is ...
- 9,394
3
votes
Limiting flow direction to D4 instead of using D8 in ArcMap?
Let me know if this is what you expecting to see:
I'll post workflow.
- 22.6k
2
votes
Stream order from flow accumulation raster
Have a look at the GRASS addon r.stream.order. You can see an overview at here and more details in the main page
- 15.5k
2
votes
Understanding hydrology and DEM results?
To understand why, have a look at your flow direction raster. In a flat filled area such as this, the flow direction is limited to the flat filled surface regardless of whatever topography may have ...
- 1,302
2
votes
Flow Accumulation Stream Buffer
Input:
Workflow:
#convert flow accumulation to streams raster
arcpy.gp.RasterCalculator_sa("""Con("facc" >= 100000,1)""", "D:/Scratch/stream_r")
#derive streams as polylines
arcpy.gp....
- 22.6k
2
votes
Accepted
Apply volumes to points on a raster DEM in QGIS
This might not be something that could solve your problem at once but it might help you further. I modeled such a thing by using GRASS GIS r.plane. Here you could define your water surface level as a (...
- 1,146
2
votes
Accepted
Could bridges prevent ArcMap from creating correct watersheds?
Yes it will mess things up completely but this is not an ArcGIS issue. How is ArcGIS supposed to know from a DEM that pipes run underground? Whitebox has developed a tool that will fix this issue and ...
1
vote
Generate a very accurate mask showing where rivers and streams are using a DEM in QGIS
You most likely know that generating a flood map requires software like HecRas and someone with hydrology skills and training. Still, it is not uncommon for people to generate detrended surface ...
- 9,394
1
vote
Generating Basin Layer Using Hydrology Tool gives ERROR 010067
Error 010005 is saying is that your file is too big to handle, and at some point ArcGIS ran out of memory. Some general ways one can deal with too large of rasters are:
Parallel processing (see @...
- 2,362
1
vote
Accepted
Stream Feature generated from DEM is missing data
SOLUTION: I used TauDEM to correct the stream network using the DEM. Below are my results. It is still not exact but it is a huge improvement and definitely usable for my work. Here is a link to a ...
1
vote
Stream Feature generated from DEM is missing data
Picture below shows talweg, generated by using flood depth and flow paths derived by using Hydrology tools:
As one can see flow paths depict channel shape in a well defined valleys without ...
- 22.6k
1
vote
How do I know topo layer contains DEM-altitude? ArcMap 10.3
I assume that you mean you have some layer and you want to know whether those data are elevation data of some other data.
If so, find some place on that surface where you know the elevation and check ...
- 9,394
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