I just used the tutorials from this page https://grasswiki.osgeo.org/wiki/Creating_watersheds to extract the stream network - however it could be more accurate so was wondering is r.terraflow a better option for me. I was using r.watershed originally
Do you know why sink filling is needed for r.terraflow and not for r.watershed? Thanks. On Wed, Dec 6, 2017 at 11:42 AM, Marco Alicera <[email protected]> wrote: > How did you add culverts?! > Such a great question and I also wonder how you did. Short ago I knew > about Itzï and its ability to do it with SWMM > http://itzi.readthedocs.io/en/latest/tutorial.html#culvert-modelling. > Looking forward to testing it > -- > Marco > > 2017-12-06 9:24 GMT+01:00 Shane Carey <[email protected]>: > >> 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* >> >> _______________________________________________ >> 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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