Creating Polygons in ArcGIS Pro

hi all um digitizing uh aerial photos to make polygons for layers um this is the week five normally depending on the weather we might do it earlier so this is a little video to show you how to do that the data for this i've already put into a project for everybody um so there's a layer for canopy and uh and a um and an air photo everything all set up for you so you can simply open project in the bottom left corner of the arcgis pro and zip to your folder whether it's on one drive or a usb wherever you're storing it in my case it's in week five okay and you'll it'll show up as a aprx called tree canopy okay don't worry about that that's simply because we've got an older version of our problem my laptop okay so here's our our map in the center here we've got a canopy layer which is a polygon so you can see it's a closed loop rectangle here you've got a near-map rgb air photo underneath nice and current and at the bottom here you've got the polygons that are already present and if we click on one of those polygons you will be able to see it highlighted so this is one way of doing it you can simply click on there and it will highlight that feature that's already been created now i've gone ahead and made approximately 150 uh tree canopy um polygons for you so you're free to use those ones to continue working on your canopy cover layer but you're also welcome to highlight everything that's here and delete them all and start over run it yourself that's that's entirely up to you okay so now we're at the point where we're going to start creating true features so we're obviously going to be in the edit layer and we're going to click on our canopy layer and we want to create features now it brings up the create button in the ribbon here in the edit ribbon and over on the side here we've got canopy and it recognizes that it's a polygon geometry underneath here we've now got our options for editing okay so we've got point and click create polygon features one vertex at a time we've got a circle feature a rectangular feature an ellipse feature and a freehand feature okay we've got some other ones in here uh autocomplete freehand tools so it'll automatically close off loops for you if you want i haven't used those for trees before we also have a vertex editor and a clipper here so we can trace along shapes if need be we're not interested in topology today so it's probably not necessarily okay back up in the top layer here in our edits we've got the select tool these are the tools that we'd probably make use of as we're going through okay so we can just clear the selection the one that i've previously highlighted there we don't want to do anything to it um and so now we're we're right to start uh mapping tree poly entry canopies if i just zoom in to a little section here you can see some of the decisions that you're going to need to make some trees have got a nice sharp outlined canopy that's easy to spot easy to easy to identify others have got a much more sparse canopy and a diffuse boundary that makes it quite difficult to identify exactly what's tree and what's what's not tree where the canopy ends okay so what we'll do is we'll go with first principles now in this case you're simply going to click at each point around the edge of the tree canopy uh to mark where the boundary is in the increments little steps going around like this and it's up to you this is this is your time to interpret where that boundary is if you think about it if somebody is asking you to do this to uh you know calculate how much tree cover a a property has how many you know what proportion of the of the property is covered by trees where you draw that line can make a big difference to the results that you get so thinking about your assumptions behind the model that you're creating and how consistent you are with that is an important part to finish a sketch you just press the f2 button so just hit f2 and now we've got a tree canopy polygon okay now that if we went and had a look at a larger one say the bamboo here the bamboo along the main path that would take us a long time to go around point and click each spot okay working way around all of that so there are other ways to speed things up first one i'm going to show you is the circular tool so here's a reasonably circular tree canopy and palms are another one they're a classic uh circle okay so for the circle tool all you do is you click once in the middle drag out to a point where you're happy that you've captured the tree canopy click again and it generates a circle for you so that's that's a very simple two clicks to create the tree canopy the next one that's in here is an ellipse feature so not all tree canopies are perfect circles okay and if we've got an ellipse shaped tree canopy like this one along here you could sit there and you could click around the edge it would take you some time or we can use the ellipse tool and once again click in the middle draw it out along an axis long axis click again and then draw out across the other axis and then you can just move that around until you're happy that you've actually captured that tree canopy and the third click will make the feature for you so we've got pointy clicky we've got circles we've got ellipses and finally we've got the freehand tool now the freehand tool is really useful for complex tree canopies that are weird shapes okay so if we have a look at this dark tree canopy in here we've got a weird shape that wraps around a bit of palm tree here and disappears underneath other canopies so with the freehand tool you click once to start and then wherever your mouse tracks the software automatically builds a line that follows so all you've got to do is run around the edge okay so we click once run around the edge like this okay and f2 to finish and now we've got what is a quite organic and difficult shape nicely digitized okay and that is creating geospatial data in the form of polygons um just remember once you've been doing this for a little while every 10 minutes or so make sure you hit the save button okay you do not want to come back and have to do these again yes we want to save all of our edits okay and in the select here if you want to get rid of that so you can just get rid of the active one you can simply click the clear here and if we wanted to select that one back again we can just pick it up and down in our table of attributes here if you click show selected records it will show you the shape area so that tree canopy covers about 200 square meters thank you all

Channel: Geospatial Information Science

Views: 1,119

Rating: 5 out of 5

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Id: RexCiwyNShs

Length: 8min 36sec (516 seconds)

Published: Thu Feb 04 2021