Hi Mark, Thanks for your reply! Sounds great. How did you add culverts or other artificial flow control features to achieve water flowing through roads?
I have a rivers layer and I compared it the streams I've obtained from r.watershed and r.watershed appears to not match these streams (which were accurately digitised) and I was wondering if I had a better resolution DTM would it solve this problem? Also, why is sink filling needed for terraflow and not watershed? Thanks for your help :-) On Máirt 5 Noll 2017 at 23:43, Mark Seibel <[email protected]> wrote: > Hi Shane. > > I'm happy to report that I've modeled overland water flow with r.watershed > for over a quarter million acres, consisting of several large project > sites, at 1 meter DEM resolution. The data source was LiDAR points to > make the DEMs. > > At this resolution, it becomes necessary to add culverts, or other > artificial flow control features, to achieve water flowing through a road. > Otherwise, water is routed along roads until a lowest point is reached for > crossing. > > I also use r.terraflow outputs as ancillary data to help drop in culvert > locations and help provide guidance in problem areas. > > My geographic area is central Florida, which is very flat and full of > topographic depressions known as wetlands. These depressions interrupt the > stream network continuity in reality, but r.watershed does a fantastic job > making a continuous drainage network model, especially in these difficult > areas. > > Happy Modeling! > > Mark > > On Tue, Dec 5, 2017, 3:49 PM Shane Carey <[email protected]> wrote: > >> Hi, >> >> I am trying to extract river network from a 5m DEM with some success >> using r.watershed. Has anyone tested this algorithm on high resolution >> LiDAR data for example - 1meter DTM and what kind of results have they >> obtained? >> >> Thanks >> >> -- >> Le gach dea ghui, >> *Shane Carey* >> *GIS and Data Solutions Consultant* >> > _______________________________________________ >> grass-user mailing list >> [email protected] >> https://lists.osgeo.org/mailman/listinfo/grass-user > > -- Le gach dea ghui, *Shane Carey* *GIS and Data Solutions Consultant*
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