Latest Contributions by ChristineDartiguenave

You can skip the QC tool if the results seem correct. If you see weird behaviors, you may always come back and QC. Usually QCing up front may be better so that you do not have to rerun the entire process multiple times. It is not mandatory however. Christine Dartiguenave Esri Water Resources Team ... View more

Synthetic streams are derived from the flow direction. They will always be oriented in the direction of the flows and their direction will match the direction of the underlying DEM. The direction of user specified streams may not match the direction of flows based on DEM in flat areas. So we need to adjust the direction in the flow direction grid to enforce the direction in the direction of the streams. Christine Dartiguenave Esri Water Resources Team ... View more

Check use case 5 in http://downloads.esri.com/archydro/ArcHydro/Doc/Overview%20of%20Arc%20Hydro%20terrain%20preprocessing%20workflows.pdf . Use case 5: Combined dendritic/deranged terrain with known sink and stream locations (using synthetic streams) 1) Create Drainage Line Structures using your input streams 2) DEM Reconditioning (using strlnk previously created as input stream). 3) Create Sink Structures (using you lakes as sinks and pass the stream as draft input line: will create a sink point at end of line). 4) Level DEM (this will enforce and level down the sinkpoly coming from lakes: make sure you set an offset to realy enforce them). 5) Fill Sinks (pass your sinkpoly so that they do not get filled) . 6) Flow Direction. 7) Adjust Flow Direction in Sinks: will ensure that within the sinkpol/lake water flows toward the sink point located at the end of the stream). 😎 Adjust Flow Direction in Streams: will ensure that once the flows reach the stream, they go along the stream.. Christine Dartiguenave Esri Water Resources Team ... View more

You will use if you have known Streams you want to use. Create Drainage Line Structures will create a rasterized version of those streams. This tool also create StrLnk which you can use as input Str raster in DEM Reconditioning (this way we use the same raster). Christine ... View more

You can use Sink Evaluation instead. It generates SinkPoly that contains all the sinks attributed with depth, areas and drainage areas among other characteristics. You can reselect the sinks to use for the analyses based on your criteria. Note that we created Sink Prescreening because Sink Evaluation would not be process big datasets. Now it can, this is why you do not have Sink Prescreening in Pro. Christine Dartiguenave Esri Water Resources Team ... View more

To avoid being filled back in, a stream must either exit the dem or end in a sink. In your case, create a sink point at the end of the streams, buffer by 1.5*cell size to create a draft sink polygon and then use the Create Sink Structures to create the SinkPolygon/SinkPoint. You can look at the Stormwater processing workflow for help. Christine Dartiguenave Esri Water Resources ... View more

You do not need to run the tool "Adjust flow direction in streams" when the streams are generated using Stream Definition based on the flow accumulation raster. This tool is used when the Streams (Drainage Line) are created using Create Drainage Line Structures, i.e. you are trying to match the geometry and digitized direction of input vector streams, which may not match the direction provided by the underlying terrain. This tool ensures that once the water gets into the stream, it follows the direction of the digitized input streams. In flat area, the water may not go the right way otherwise. Christine Dartiguenave Esri Water Resources Team ... View more

Yes I believe it will fix your issue. Christine ... View more

I could reproduce the issue when runnning in background. Foreground completes successfully. Will take a look. Christine ... View more

Which version of Arc Hydro are you using? I tested the tool on one of my dataset and it worked correctly. What type of input data are you using? Christine Dartiguenave Esri Water Resources Team ... View more

You need to use the geoprocessing tool from the Arc Hydro Tools Python toolbox (under Terrain Preprocessing Toolset). : ... View more

Peter, First, when using DEM Reconditioning you have the option to raise all values in the DEM to end up with a DEM with all positive values. In the past, it used to be an issue down the line when the DEM contained negative values. This is not the case anymore. So this is now a personal preference. I usually do not check it and keep the default (unchecked). It does not hurt either way. Also, DEM Reconditioning is used to set the flow direction and does not contain real elevations - it is not to be used to extract elevations or compute slopes. So it is ok if the range of values is totally different from the original DEM. Secondly, if you have a very flat area and a known network, you should use Create Drainage Line Structures with your input Streams to create DrainageLine and StrLnk as a rasterized representation of your streams that will be used as input by DEM Reconditioning. You need to make sure that these streams can get out, by either exiting the DEM or ending in a sink otherwise when you Fill (except in the sinks) they will be fill back up and you will lose the benefits of reconditioning. You should also use Create Sink Structures to burn in your known sink and make sure you pass the end of the stream in you sink polygon as a Draft SInk Point. This will ensure that after reaching the sink, the water flows into the sink point. You will need to Level the DEM using the output SinkPolygon to enforce that sink as well. You will eventually need to fill to force the water to get out (toward a sinks or the outside). After creating flow direction, adjusting it in your sinks, you will also adjust it with your streams using the strfdr flow direction. This will ensure that once the water reaches a stream, it will stays in the stream following the digitized direction of the streams. Now if the water still does not flow toward the streams the way you want, you may need to enforce the known boundaries as well to make sure when the DEM gets filled, the water goes the right way. I would start without this first to see how it goes and add that step if needed layer on.  So to summarize try the following workflow to create preprocessed data to support a delineation (without enforcing the boundaries): 1. Create Sink Structures (pass your known sink polygon and pass the from node of the stream in your sink as input draft sink point at least). 2.Create Drainage Line Structures -> will create your DrainageLine, strlnk (can be used as str) and strfdr which is the flow direction in the streams. 3.DEM Reconditioning (using strlnk just created). 4.Level DEM (using AgreeDEM, SinkPoly and pass an offset of 1000 at least - this burn in your sinks). 5. Fill Sinks (pass SinkPoly so they do not get filled). 6.Flow Direction. 7.Adjust Flow Direction in Sinks (pass outputs from Create Sink Structures). 8.Adjust Flow Direction in Streams (adjust previously adjusted  fdr using strfdr created by Create Drainage Line Structures). 9. Combine Stream Link and Sink Link (using strlnk and sinkpntgrid, make sure you pass DrainageLine as well to keep the IDs in sync). 10.Catchment Grid Delineation (using Link) 11.Catchment Polygon Processing 12. Adjoint Catchment Processing 13. Sink Watershed Delineation 14 Append Coastal Catchment (to create catchments with no associated links within your area of interest to speed up delineation) Christine Dartiguenave Esri Water Resources Team ... View more

Not at this time. We needed that tool because Sink Evaluation could not handle large rasters at the time it was developed. Since it now can, we do not use this tool anymore and start directly with the Sink Evaluation tool. Is there any reason why you want to use it? Christine Dartiguenave Esri Water Resources Team ... View more

We are not planning to update the basic step by step tutorial. I started doing just that and with more than 250 tools and many options on how to implement your workflows, it quickly became a nightmare to develop and maintain. So now our objectives are to try to document each tool in the Python toolbox itself and to develop some workflow oriented documentation, similar to what we have done for stormwater. We are planning to revisit the main terrain preprocessing workflows and are finalizing an updated stormwater and a new flood oriented document. If there are any area/workflows that you would like to see documented beside those? As for the Arc Hydro training, you can contact Dean Djokic (ddjokic@esri.com). He schedules and teaches them, and will be conducting 2 workshops at the Water Conference next year (on stormwater and on flood). Christine Dartiguenave Esri Water Resources Team  ... View more