Latest Contributions by MarkBoucher

I'm not sure if this is exactly what you want... I just played around with this. If the value in the flow direction (fdr) grid is 255 then a flow tracing tool stops there. I believe 255 is an "official" direction in the fdr. You can find this in the flow direction helps. I took a polyline layer that represented my creeks and added a integer field to the table and made all the values 255. I using the Conversion>To Raster tool I converted the polylines to Raster255 taking care to set the cell size equal to my fdr raster. I then used the IsNull command to make my "IsNull" raster. This is a raster where locations with cells equal to Null are 1 and the cells that had 255 were 0. I then ran the Con() function on the IsNull and tested if the value in IsNull was 0. If true, the answer is the result is Raster255, if false the answer is fdr. This process created a final fdr255 raster that had 255 as the flow direction in the creeks and when I use the flow path tracer, the trace always ended at the creek. The red lines in the image are flow traces, the blue creeks, the green watershed boundaries. It was easy to set this up in model builder. I assume this "logic" can be put into a script. You'll want to carefully specify which creeks/streams/rivers to use for creating the Raster255 layer. [ATTACH=CONFIG]16955[/ATTACH] ... View more

I've also dealt with issues like this; so much that I created a thread to share/store potential solutions. (http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers?p=164676#poststop) Good luck! ... View more

Very good document every Arc Hydro user should have: http://downloads.esri.com/support/datamodels/Hydro/Comprehensive_terrain_preprocessing_using_Arc_Hydro_tools_2008.zip  I found it here: http://support.esri.com/en/downloads/datamodel/detail/15. ... View more

I'm using Arc Hydro for ArcGIS 10 (version 2.0, September 15 2011). I've never used "Weighted Flow Accumulation" and so haven't notice if it was there or if it was missing. My typical work flow doesn't take me that far down the Terrain Process menu. ... View more

Check out 3D Near. It seem's to have other options though I didn't see azimuth as you want it. ... View more

Peter, Try this: Delete everything you can in your temp folder: Mine is C:\Users\mboucher\AppData\Local\Temp. Get out of ArcMap first to clear temp files related to your project. You can do this without getting out of ArcMap through the ArcHydro Toolbar under ApUtilities>Additional Utilities>Clean User's Temp Folder. This solution has address several different raster processing problems I've had. (Taken from http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers which may have other info related to raster calculation problems). ... View more

The "Near" function will give distance and, I believe, direction. http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//00080000001q000000 ... View more

Try looking at these threads: http://forums.arcgis.com/threads/53316-Why-can-t-I-define-a-stream-network?p=182644#post182644 http://forums.arcgis.com/threads/52110-Terrain-Processing-Steps.?p=178067#poststop These have been added to this thread which has other ideas and threads you may want to look into: http://forums.arcgis.com/threads/48100-ArcHydro-Problem-Solvers ... View more

A couple more links related to the Arc Hydro Process: http://forums.arcgis.com/threads/53316-Why-can-t-I-define-a-stream-network?p=182644#post182644 http://forums.arcgis.com/threads/52110-Terrain-Processing-Steps.?p=178067#poststop ... View more

There is a program called PRISM, developed at Oregon State Univ that does this in a very complex way. I think it does the spatial interpolation from rain gauge points using 12 or so variables such as elevation, aspect, etc. I do not believe it is an ArcGIS tool in any way, though I'm certain it is raster based. My personal conversation with some working with it at OSU convinced me that it is not meant to be run by the "average" hydrologist. It is very tedious to use and an expensive tool to use to set up for a state or region. Few people are trained on it. It is being used by NOAA in the latest NOAA Atlas 2 development. Having said all this, I suspect there are parts of the PRISM logic that would be useful to the "average" hydrologist or researcher that could be emulated in ArcGIS using Spatial Analyst. Might be worth looking into. ... View more

Are the values in the created raster and the original raster the same or different? Use the identify tool to find out. ... View more

You can convert the contours to a DEM (raster) using Spatial Analyst Tools>Interpolation>Topo to Raster. Then extract the elevation of the DEM to the points that represent the structures using Spatial Analyst Tools>Extraction>Extract Values to Points. The finer the DEM (the smaller the grid size), the more accurate your structure elevation will be. ... View more

To get density, you can divide the length of road by the city area. ... View more

Assuming the City name is in the city layer, I would try: intersecting the roads and the city boundaries (Analysis Tools>Overlay>Intersect), open up the attribute table of the created layer, recalculate the shape_length field using the "Calculate Geometry" function, (choose the units you want in the table) select "Reports>Create Report" from table options menu, in the reports wizard choose the city name field first and the shape_length field second, make sure the "Report Field Contents Field" is the same as the city name field. click finish There are other options that might make the report nicer looking or format it differently, but when I did this I got a what I think you want. I tried it again with a complicated options, but there are a lot of roads in our county and 10 cities, so I'm not waiting for results before I finish this post. ... View more