Latest Contributions by MarkBoucher

The reason that I run my ArcHydro and GeoHMS from ArcCatalog is that I've developed models and scripts to automate my workflow in order not to have to create mxds and which has drastically improved the performance of me processing large study areas. That's awesome, Peter. I hope to get there some day. ... View more

When a cell is lower than all neighbours it is lifted up (during the flowdirection-process) to the height of the lowest neighbour. This is incorrect. The cell is lifted up during the fill sinks process. The normal process for DEM Reconditioning is in this order: burn in streams, build walls (if needed), and then fill sinks. This results in a "hydrologically correct" DEM if your streams and walls are all in the right places. All of these are elevation models. You have to perform these functions because the "raster world" misses details, can't see underground or under bridges, and is too coarse to distinguish subtle ridges and swales. These DEM Reconditioning processes make sure the elevations are such that when you perform the flow direction process on the filled DEM, the flow directions will be correct. The elevations in the filled DEM may be 1000's of feet off, but that does not matter. When you perform the flow direction function on the filled raster and have a flow direction grid the elevations are not used in the rest of the watershed processing of the process in defining streams, catchments, etc. Of course, when you need a correct elevation, you have to go back to the rawdem. Doing the flow direction before filling, really does not take into account the filled sinks. Hope this makes sense. My posts at http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers explain the process in more detail as I've learned it. ... View more

Now the question is, which coordinate system should I use?  Is it best to keep it all in meters? My gut tells me that the data should be in the same coordinate system and units to work correctly. ... View more

I'm a novice at Python. What I do know is that indents mean something in if-then code. I would have written the original script with at least one space in front of the words "Newfield". When I paste it in this forum's text box, the spaces get removed. That could be why Anthony's code didn't have the indentation. ... View more

I am filling the reconditioned DEM, but it doesn't even look like the stream is burned into the reconditioned DEM to begin with. Some thoughts: Make sure the processing extent is set to include the area of your analysis. If not, the DEM Reconditioning. will run, but will do nothing. (see No. 5 in list linked at bottom of this post). It seems like you are working in an area with lots of elevation change. If you are working in flat areas, make sure your most downstream agreestream feature extends beyond the DEM and that you internal agreestream features connect. If not, you may burn the stream, but the fill tool will just fill it up again. Burning "past" the edge of the DEM and making sure the internal features connect at the downstream ends avoids this. Having said that, you can burn a culvert or stream through an embankment; you just have to make sure the ends of the feature reside in the lower DEM grids of the creek/river. The burning will lower the embankment and the filling will fill it up again but just to the creek/stream bed. You mentioned both a 10m DEM and a 1m DEM. To burn the roadside ditches in you will need a very fine DEM. It seems to me that a 10m DEM will not do that for you. Converting the 10m to a 1m would help. You can use the Resample command to go from 10m to 1m raster. (Data Management Tools.tbx\Raster\Raster Processing\Resample). Make sure you burn the streams (DEM Reconditioning) and then fill. See http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers?p=270146&viewfull=1#post270146 for more Arc Hydro set up tips. ... View more

You can also select all the the graphical element such as graphical points, lines text using the menu command Edit>Select All Elements. Then you can delete them all at once. There is a toolbar command in the Draw Toolbar. ... View more

Use the Raster Mosaic tool with the option that the values of the LAST raster are the ones to keep. Then enter the raster with the correct values last. Works on raster datasets only. ... View more

I commented on another thread where the user wanted to analyze the values around a grid cell.  I found the "Shift" tool. http://forums.arcgis.com/threads/75804-surface-angle-in-each-cardinal-direction?p=265962&viewfull=1#post265962 You might be able to do the same by instead of just the 4 directions (N, S, E, W) that this user was wanting to deal with, you could make fdr grids for each of the 8 directions. Then use the the Con() function with the flow direction grid as the test to determine which of the 8 grids to do the math with. The logic is probably simple and model builder could make it easy to via trial and error. ... View more

Check and see if this answers your question: http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?id=1151&pid=1146&topicname=Surface_Volume_(3D_Analyst). ... View more

If you are using ArcGIS 10, I would upgrade to Arc Hydro 2.1. Assign UniqueID is still in the ApUtilities menu in versions 2.1 (ArcGIS 10) and 10.1 (ArcGIS 10.1) for sure. We added it to the toolbox but did not remove it from the toolbar. Christine Dartiguenave Esri Water Resources Team Upgraded to 2.1 and now have the Assign UniqueId option. Thanks! ... View more

Most drawings I've seen have curb lines and back of sidewalk lines. You must be creating a pedestrian travel network or something. ... View more

Off the top of my head... Check that you are in or out of edit mode (whichever you should be for the tool). Make sure you are only selecting features from one layer and/or possibly only one feature at at time. ... View more

Related thread. They say 2.1 is not out for 10.1 yet. Is this true?http://forums.arcgis.com/threads/76951-Missing-Flow-Direction-with-Streams-tool-in-10.1-BETA?p=270520&viewfull=1#post270520 I looked on the ftp site and the names of the folders in the 10.1 folder don't call out the ArcHydro version. Their named "ArcHydroTools10.1" with no version indicated. I'm using 10.0 so wouldn't matter to me yet. ... View more

ESRI Arc Hydro ftp site information: http://forums.arcgis.com/threads/71180-Error-when-DEM-reconditioning?p=255178&viewfull=1#post255178 ... View more