Delineating Drainage Basins in ArcGIS Pro

hey this is Phil white the earth sciences librarian at cu-boulder wanted to share this quick video on how to delineate a drainage basin or a watershed in arcgis perot i didn't see any videos on youtube that demonstrated how to do this in arcgis pro so i thought i would upload one real quick so you want to start off with the de m and i got this from yes jess is just a DM one meter resolution that covers the kind of area just south of boulder including the Flatirons the first thing I recommend is clipping this down because if you're running it over a big DM it's gonna take a while to do a few of these tools maybe the easiest way to do this is to zoom in on an area that you're interested in and then go over to your DM right click and go to data export raster which will open up this export raster dialog box importantly you want to give it a name like click DM and you also under under clipping geometry you want to tell it current display extent if you're doing it by this message method you can also close a bio by another layer if you want to so go ahead and export that and when it's done it should and your new clipped DM to your map and I just turned off my Olin and now I have a small ID in to work with so now we're gonna run a few tools to delineate this watershed first go to analysis you can go to your tool sets here click your toolbox that will open up the studio processing tab over here and I already have a few things open but basically you'll want to get down to your spatial analyst tools and then into the hydrology toolset and the first tool you want to run is the fill tool the fill tool basically smoothes the de em out a little bit to remove some errors what they call sinks and your input is going to be your clip TEM I give your output a name something like de M fill and run it this might take a minute okay so that totals all done and that took probably a minute and a half on the small version that I'd created basically the fill tool you want to do it so you don't have a drainage basin that ends up being one cell so once you've ran that tool the next tool in this process you can go back over your to your geoprocessing tab click the back button and you want to do the flow Direction tool next your input raster will be the diem fill output will be we'll just call this flow Direction diem just like that go ahead and run that just watch it and take us along okay that one only took about 15 seconds and we have this image this raster that basically shows direction of each of the downward slope as determined by the the largest drop between one cell and it's and all of its neighbors so once you've run that tool you can open your geoprocessing tab again hit the back button and we can go ahead and run the basin tool and your input will be this flow Direction DM your output we'll just call it basins run it okay so now that that's done what do you have here are is a new raster and it's just colored each different drainage basin in a different shade of gray at this point you've delineated your your drainage basins but one thing you may want to do is convert this to a vector polygon so to do that we can go back to our geo processing tab hit the back button we can close out our spatial analyst tools we're done with that for now and you can go to your conversion tools and go drop down the from raster toolset and go to raster to polygon your going to put raster will be your basins we'll call this Basin polygon and run it okay so now we have polygons here for each Basin you can also if you only need one of them you could go to your map ribbon I go to select click on one of them right click on your layer go to data export features give it a name like whatever it's called my drainage basin run that and I turn off on the other layers now I have just my basin you can click on the icon here which will open up your symbology dialog I will probably default to this page under gallery but if you click on properties you can go in and select your own color scheme I'll change it to no color with a red line click apply and we've delineate 'add a basin so I should also mention that the basin tool is one way to do it you can also use the watershed tool which it works a little bit differently it can delineate a watershed based on an area above a certain elevation and there's a few more steps for computing it that way the way I demonstrated is kind of the simplest way and I'm gonna put a couple of links in this video that kind of link out to more information and show other methods of doing the same task so that's it for now feel free to email me if you have any questions at Philip dot white and Colorado edu and bye for now

Channel: Philip White

Views: 4,532

Rating: 5 out of 5

Keywords: GIS, Hydrology, Watersheds

Id: zxFCd1iEajg

Length: 8min 24sec (504 seconds)

Published: Thu Dec 27 2018