Latest Contributions by MarkBoucher

I run the breach before filling. The breach lines (usually the agreestream lines for me) basically make hole in the walls that you may have created (built). I don't think they breach or lower the DEM. If you are using tools other than the Arc Hydro tools (I'm still in Desktop version) the process you would follow might be different. In the Arc Hydro workflow and tools, the Breach line is chosen in the "Build Walls" dialog box. If I were given the same task, and using Arc Hydro, I would definitely add an agreestream (Arc Hydro default name) polyline right where road embankments begin to raise the streams up on either side fo the culvert or bridges (basically connect the thalweg of the stream I see on each side of the embankment). Other major infrastructure (bypass pipes, etc.) could also be burned in. A wall could be created wherever there is a long low feature that the DEM doesn't define a linear rise (railroad embankment for example) and the breach line (again I usually use the agreestream) would breach this wall when the processes are run. If you have a dam that you want to define the stream through, simply putting a agreestream line through the dam will do the job of "breaching" the dam. There would be no need to build a wall at the top of the dam (unless the DEM cells are large and the dam embankment is "fuzzily" defined). When that is done, the next step is to fill the sinks. I look for places to put breach lines by running the process through the fill stage and then doing the raster math to surtracted the rawdem raster from the fil raster. This shows me where things were filled and usually shows "flooding" behind embankments so I can know where to burn the streams through them. If you have a large DEM grid size and steep canyon walls, burning through road bridges and culverts may not be nessesary. Hope this helps. Feel free to ask for clarifications. Mark ... View more

That makes sense. Also, if you convert the points to rasters then you would think that they would line up with the raster cells and be on the raster cells you are interested in. If you then converted those back to points, you would think they would be centered on the raster cells (if you needed to use the points to extract info from the raster). ... View more

If you convert the polygon mask to a raster (with origin and cell size the same as the raster you want to extract) can you use that raster as a mask?  Would it include the all the edge cells you want? ... View more

There is this thing called "topology" that is used for this. Basically, you Create a geodatabase. Create a new feature dataset in the geodatabase. Copy or move the polygons as a feature class inside the feature dataset. In that feature dataset, alongside the polygon feature class, create a new topology. Onclude the feature dataset in it. You then add rules for the dataset such as Must NotOverlap and Must not have gaps. Then you validate it. The result show you highlighted gaps and overlaps. There are topology tools that allow you to decide what to do with the overlaps or gaps: that is to assign them to one side or the other of the overlap or gap. Hope this makes sense and helps. ... View more

Here is a possible process. I won't detail how to do every step here, but they should be doable. Use ArcHydro to create catchments with drainlines, etc. Intersect the line represending the road with the DrainageLine layer (results would be points). Create a field in this point feature class called "Name". (For later coping the HydroID of the drain lines to the to the "Name" field in BatchPoint layer.) Using the points extract the value of the flow accumulation (fac) raster to another field. The fac represent the number of upstream grid cells. Maybe calculate the watershed area that fac represents in another field (fac value x (grid cell dimention)^2) Create one random BatchPoint (to be deleted later) to set up the BatchPoint feature class . Select the points by the size of watershed (fac value x (grid cell dimention)^2) to reduce the number of points to include only those watersheds big enough to concern you. Copy the selected points to that BatchPoint shape file. The"Name" field should be fill in with the values in the "Name" field of the points copied in. In the attribute table, for BatchPoint, calculate the BatchDone, SnapOn, SrcType fields as needed (normally 0,1,0 and Outlet, respectively). Use the BatchPoint layer to create watersheds for these key points along the road. The "Name" should show up in the resulting Watershed layer. Hopefully this process or something like it will work for you. Mark ... View more

If the routes perfectly intersect each other, you might try using the Analysis Tools>Overlay>Union tool. This would result in a shape file (XY) with all of the combinations of the fields for both shape files (X and Y).  You could simplify this output and use that going forward. Or you could create a speed limit field in X  and you perform a join between X and XY using the ID field of X and the same field in XY. After the join, calculate the  new speed limit field in X to equal the speed limit field in XY then remove the join. The success of this second approach will depend on how well the speed limits "match" the route segment. If you have more than one speed limit Y for a single segment in X, then keeping the XY layer may be the way to go so your will have segments in the routes with multiple speed limits. Also if the route lines don't perfectly intersect each other, you may get some missing segments. Hope this makes sense. If you want, let me know which one works (or not). Best, Mark ... View more

Kathy, Sorry, I'm not aware of the IDW options/effects in the topo to raster tools. Maybe someone listening can address that. Mark ... View more

Sorry Kathy. I had noticed that myself and quickly edited the post with this correct link. Possibly you were responding via an email reply and not looking at the esri Community page.  Here's the correct link again. https://www.contracosta.ca.gov/DocumentCenter/View/3914/Mean-Seasonal-Precipitation-Raster-From-Dwg-B-166-PDF?bidId= Mark   ... View more

Kathy, Sorry. By "train" I meant that after I create the raster from contours and then create the contours at smaller intervals, I see if the newly created contours make sense. If not, then I add intermediate contours and repeat the process. This adding of additional intermediate contours is what I call "training". If you look a the document I linked, you will see some maps with circled areas that I felt I needed to add more intermediate contours to "train" the raster to output more reasonable contours. Hope this makes sense... Mark ... View more

If you can create a raster from your contours, you can create contours at any interval from that raster. What I did was create supplemental contours by manually interpolating halfway between the starting contours to train the raster to create contours that I agreed with. So there was still some subjectivity involved. - Mark ... View more

Kathy, I did something similar for rainfall contours using ArcMap and Spatial Analyst. I documented it here. https://www.contracosta.ca.gov/DocumentCenter/View/3914/Mean-Seasonal-Precipitation-Raster-From-Dwg-B-166-PDF?bidId= It was a while ago, but after looking at the document, I now recall I made a raster from the manually created (digitized) contours, from the raster generated finer contours, checked the accuracy of those finer (smaller interval) contours. Then I manually interpolated between the initial manual contours where needed by creating lines between the initial contours and then drawing new contours by clicking the midpoints of those lines. Tedious, but it worked. Possibly what you need is somewhere in that process. ArcPro may have a simpler tool. Mark ... View more

As I was learning the Arc Hydro process, I used to burn in all the streams using a streams layer. Then I discovered the DEM I had was 10'x10'. I realized that the majority of the stream can be identified during the Arc Hydro process. I then limited my streams to be burned to problem areas where the terrain (DEM) didn't correctly reflect the real flow path (bridges, fuzzy/confusing DEM spots).  The resolution of your DEM dictates a lot. What I see in you image above  (lower right quadrant) appears to be a very detail DEM. Is that the resolution of your DEM or another image with hillshade? ... View more

I saw this tool while looking for something else. I have not used it, but the description seems to fit your need. Mark https://desktop.arcgis.com/en/arcmap/latest/tools/spatial-analyst-toolbox/flow-distance.htm ... View more