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Arc Hydro will not calculate flow rates in cubic feet per second (cfs). Arc Hydro is used to help the parameters that go in to equations or models that are used to calculate the flow rate. The tools in Arc Hydro are made to help automate the determination of the the parameters that come from watershed delineation process such as area parameter, flow path length and slope, watershed centroid, using the watershe polygons to convert raster based land values of impervious surface or infiltration rates to averages for the watersheds; thing like that. Hope this helps, Mark
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09-24-2020
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Good instructions. Has the migration happened yet? Looks the same so far. Thanks, Mark
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09-15-2020
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You may be aware that ESRI is moving GeoNet to a new platform. To preserve this thread I've exported it to a Word Document. The option to export to a pdf wasn't working and it looks like some paragraph numbering was lost in the simple copy/paste to Word. Once the new GeoNet is up and running, and if we last this thread, I will post the document somewhere I think it is searchable. Best, Mark - Original Arc Hydro Problem Solvers poster.
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08-12-2020
09:31 AM
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Annina, I don't recall seeing that recently. First: I assume you have filled the sinks under the DEM Manipulation tools.. If not, make sure you do that. Second: The black lines ( DrainageLines) appear to cross each other. Some look like they follow flow paths defined by the DEM (irregular in alignments), others look long and sweeping and like they wouldn't follow a path defined by the DEM. These appear to have have more generalized alignments. Make sure your agreestream layer is correct. I try to limit the agreestream polylines in natural area and only put them in where the DEM misses where water flows under roads or bridges. In developed areas, I put in agreestream polylines where there are pipes. Third: Make sure you are setting the datasets correctly in the Terrain Processing>Data Management Terrain Processing menu. Hope this helps. Mark
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08-10-2020
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Darin, My initial thought is to suggest you check and ensure that the geoprocessing extents includes the extent of your data. In older versions the processing extents would change during a prior process and not change back if one of the prior processes didn't execute successfully. In my case the geoprocessing extents would match the patch points extents and cut off watersheds to the extent limits of the batch points. A remedy was to reset the geoprocessing extents. I have not used the "append coastal catchments" tool. Could be an error in that process that I've not encountered. If you find the processing extents is the issue, you may want to check the processing extents before and after you run append coastal catchments. I have run into a similar situation as you and gotten watersheds delineated round a small area instead of what I expected. In those cases the point I clicked was not right on the str grid and I'd get a very small watershed delineated as a result. I then would use the flow trace tool and click on the fdr cells all round the point of interested until I was certain I was on a cell that would work. A bit tedious, but it was a work around. Hope something here helps, Mark
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05-18-2020
04:34 PM
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I have not used the " enhanced flow direction grid". But I believe the stream grid (str) and a flow direction grid are all that are needed to create the stream link (strlnk) grid. The str and strlnk look exactly the same except the str would have 1's and 0's but the strlnk grid has 0's (where no stream is indicated by the flow accumulation grid threshold for str) and integers of 1 and greater. That is what's show on page 37 (pdf pg 38). in the document at http://downloads.esri.com/archydro/archydro/Tutorial/Doc/Arc%20Hydro%20GP%20Tools%202.0%20-%20Tutorial.pdf. It would be interesting to see what your str grid looks like. Looking at the image you shared, it makes me wonder if your rawdem is right.
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03-16-2020
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Emma, My first suspicion is that the inputs to the Stream Segmentation tool are not correct. They should be (at a minimum) the flow direction grid the stream grid. Mark
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03-16-2020
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Annina, I can't tell from those error messages what might be going on. The " error message" I'm thinking of is the one that appears while processing. An example is that provided in the image by Anne-Marie Dubois in her post on Aug 8, 2019 7:22 AM. If you can screen shot the run time error messages it might reveal something. I did a Google search on "arcpy memory error" a few of the results could help your Python programmer. (I suspect done this type of search already): A result in GeoNet: memory error with python A result in ERSI support: Error: ERROR 000426: Out Of Memory A result in stackexchange: arcpy - Python MemoryError when running ArcGIS Python Toolbox tool - Geographic Information Systems Stack Exchange Hope this helps. I look forward to seeing the solution. I want to get my Python black belt doing Arc Hydro for me soon so your experience will be goo to follow. Best, Mark
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02-27-2020
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Annina, Thanks for the ego boost. I am experienced through the "beating the head against the wall" ArcHydro methods gauntlet, so I guess that makes me an "expert". I am not a Python pro at all. I have gotten accustom to deciphering the ESRI error messages. If you can send the text or a screen shot of the error message, I'll see if that can point to a potential problem. Are you processing the project on your local machine or over a network? That can make a difference, in my experience. Best, Mark
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02-26-2020
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Jack, You may want to check out the thread ArcHydro Problem Solvers and see if there is an answer there. I'm not familiar with this particular error. The error message seems to point to the grid, though in the geoprocessing, the tool may convert vector data to a grid, so I can't say for sure if it is the grid you input, or a temporary grid. The inputs to the LongestFlowPath tool are a Drainage Area (polygon) and Flow Direction Grid (grid). Check your inputs to make sure they are correct. Check your inputs to make sure they are in the right projection. Check you processing extents to make sure they cover the processing area. Best, Mark
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02-05-2020
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