I'm pretty new to GIS however I am using ArcMap 10.0 and ArcHydro 2.0?.. anyways the pre-processing for watershed delineation is pretty much the same it seems with older versions of archydro.
I have pre-processed all of the NHDPlus v.2 data for the United States (i.e. built stream grids (@5000 cells), stream links, catchment grids, catchments, drainage lines, and adjoint catchments for each HUC2 and its sub-sections. I used the pre-made "fdr" and "fac" raster files that I downloaded from NHDPlus V.2 website: http://www.horizon-systems.com/nhdplus/NHDPlusV2_data.php
I want to be able to merge my created grids and layers so that I can delineate by point from wherever. Right now I can easily delineate watersheds by point within each sub-section, however if I have larger watersheds that I would like to create (i.e. Brazos R.), it doesn't delineate the entire watershed because the grids are too small for the basin. I've tried to merge the rasters via "Mosaic to Rasterdataset" tool and the layers with the "Merge" tool but it's not registering anything. I think its because I'm not calculating any cells properly? I just want to be able to delineate larger watersheds using my already pre-processed data.
Any thoughts on this or help with this would be great 🙂🙂
Hi Sydney, I'm looking to do exactly the same thing.. and also delineating basins on the Brazos R. Did you ever find a solution? If so, please post your process back to this thread. I've been surprised at how little information there is for utilizing the NHDplusV2 datasets with ArcHydro for basin delineation. There is a generic factsheet from ESRI about it (http://www.esri.com/library/fliers/pdfs/using-nhdplus-data.pdf), but I needed a few more details to follow it through successfully.
As an aside, I would be curious to know what kind of work you are doing on the Brazos... and where? thanks, paul
