Geodatabase Topology in ArcGIS Pro

in this video we'll continue to explore topology in arcgis specifically in this video we're going to look at geo database topology in arcgis you can work with topological or spatially related features using a variety of tools and environments map topology is a simple topology within ArcGIS that allows us to maintain coincident features while editing editing coincident features and you should have seen this in our previous video on editing spatially related features and topology in this video we're going to explore geo database topology geo database topology is an advanced more robust topological system within ArcGIS that is rule-based the rules define valid ways that features may be spatially related or topologically related or how they connect essentially so to work with geo database topologies you need either a standard or advanced license of ArcGIS this does not work with a basic license and you have to actually create the geo database topology within a feature dataset that includes the feature classes that will participate in the geo database topology if you refer back to our PowerPoint on topology you should see more about geo database topology and you can read about it here to learn more we're going to step through how to create a geodatabase topology add feature classes to it as well as a set of rules validate the topology and fix any errors that arise from features that are not valid based on that topology rule so the geo database topology rules are related to the types of features you have in your future classes there are rules for points polygons and polylines and there's a basic topology workflow where you design your topology you think about which feature classes are going to participate and how those features are spatially related within a feature class or between feature classes you then have to have feature classes in a future data set you create the topology add rules validate the topology and then you use the editing environment to identify and fix errors so let's just jump over to arcgis pro and see some of this in an actual demonstration so if you want if you step through the previous video you may still have your editing and topology arcgis pro project open I have mine up in here if you don't have it open please open it now if you do have it open you'll need to make sure that you are not editing so you can see my save and discard or grayed out here on my editing tab on the ribbon what we need to do first off is to create a feature dataset in this geo database now during an edit session when you are editing within a feature and within a geo database ArcGIS will not allow you to update the schema or the structure of geodatabase we're gonna create a new feature data set here about right-clicking the geo database in the catalog pane and going to new feature data set again if you are still editing feature data set will be grayed out sometimes stopping the editing session it's not enough to unlock the database for schema changes so if it's grayed out the feature data set there you'll want to close any editing panes that are open and if that still doesn't fix it you may need to close or jaws pro and open it back up to unlock that database for schema changes it should open for schema changes just by turning out anything off but sometimes it doesn't get unlocked so a restart will fix that so I'm going to go create a new feature data set before we do that let's think about designing our designing our topology so I want to look for errors in my EMS layer that we saw in our previous video we saw an overlap and a gap between polygons that I email am s layer so I want to include it in my topology and I also want to look for sewer structures or manholes that aren't connected to sewer pipes maybe they were just not connected using snapping properly and so we want to look for some issues with these two layers too so we need to include the EMS feature class sewer pipes and sewer sewer structures in a feature data set that we will then also create a topology in so feature data sets in a geo database are used for a couple of purposes the most basic thing we do a future data sets is use them to simply organize feature classes within a feature dataset so maybe you put all of your utility related information in a utility feature data set and you put all of your land-cover information in a land cover feature dataset now you can do that at any license of ArcGIS pro create future datasets in your database and organize feature classes in them in addition to just a simple organizational technique kind of similar to how you organize things and folders on their computer some advanced functionality in the geo database requires feature classes be in a feature dataset geo database topology is one of those things an important thing to understand about feature datasets is that all the feature classes in a future data set must have the same spatial reference so when you create a feature data set you give it a spatial reference or coordinate system and then any feature glasses you add to it must have the same spatial reference or coordinate system so keep that in mind as we step through this so I'm going to right click my geo database and make a new feature data set the create feature data set geoprocessing tool opens a little slow but opening nonetheless when the store opens its gonna look it's going to automatically have the output geodatabase because that's the one we right clicked the feature dataset name I'm going to call it topology demo that's not super descriptive usually it'd be descriptive based on the types of data you're putting into it but we're just going to call this one topology demo and the coordinate system you can pick a coordinate system from all of the options in the coordinate systems but since I know that the EMS layer is the first one that I want to add and work with I'm gonna import the coordinate system from here from that ems layer so this way the ems layer and the feature dataset will definitely have the exact same coordinate system in a DAT three state plane North Carolina's feet click OK to that and then I'm going to run the tool you'll see at the bottom it's running updating and the create feature data set tool completed so if I go back to my catalog window here I'll see my new topology demo feature data set now when a feature class has the exact same coordinate system as the feature data set you can copy/paste and to that feature data set so I'm going to right click EMS and I'm going to copy it and right click and I'm going to paste it into that feature data set it runs now you cannot have two feature classes with the same name in a geodatabase even if they are not in the same feature data set so I'm going to rename EMS one EMS topo for topology and we're going to work with this one with our topology rules now typically you delete this ems layer you don't want two copies of the same data because you can't keep them both updated so one workflow would be to copy the ems layer up to here delete this one and then just rename this one ems in this case I'm just gonna leave the CMS layer here but again this is the one that we're working with and and are going to create some topology rules for so now that I have my EMS Topa feature glass in a feature data set I can right click this feature data set and I can make a new topology the topology wizard create topology wizard opens and you'll see some some basic settings right here on this define tab so the name of it is going to be topology demo underscore topology it appends topology to the end of the feature data set name my XY cluster tolerance is a very small number one ten thousandth of a foot is that what that is now we're not gonna have ranks because we only have one feature class and you need to choose the feature class will participate in this topology now I could have added my other future classes to this topology now and add different rules for them that's the sewer lines and the sewer structures or manholes layer but I'm just going to do it in two steps so you can see it happened twice and have a little bit more reinforcement of how this works so when I click Next it's going to drop down to add rules so if I click here to add the first new rule I need to choose the feature class it's going to participate and there's only one option and you can apply these rules to subtypes within a feature class which gives you even more control but in this case I just want to add the rule to the feature class and so what we want to do here is we're gonna have one rule that says this polygon feature class must not have gaps between polygons I'm then going to add another rule choosing my feature class and I'm gonna tell it that it must not have overlapping areas between feature classes now there are a lot of different rules for for polygons and and how they can be spatially related or topologically related to other feature classes you might say that a polygon must have a point in it so if you had an address points layer and a building's layer you could return any buildings that don't have an address point in them as as errors to show where your missing address points lots of lots of rules think there's over 34 different types of geometries but we're going to kind of stick with some basic ones to get a feel for how this works so we've added our rules click Next you see a summary here your feature classes and your rules and I'm just going to click finish it's creating my topology and now I want to add to add the topology to the map so you can see it exists in the database like any other kind of object but when I drag it over here and drop it on the map you'll see that it adds the feature classes that participate in the topology automatically and your topology actually exists here with symbology that shows you different errors for different types of geometry as as dirty areas so a dirty area is an area that has not been validated so this entire area is a dirty area now and if I validate it checks all the features for it checks all the features and the layer and it checks them against the rules it will then show any errors based on those rules highlighted or symbolized in these different ways but there won't be any dirty areas when you make edits it creates new dirty areas that it then again have to be validated so on our edit tab under our topology drop-down here notice now we have a geodatabase topology so if you hover over it you can read about geodatabase topology actually it gives you the same topology message the bottom part enable a geodatabase topology to edit typological edges and nodes for layers that participate in that topology using tools in the modify feature pane so I'm going to choose that geodatabase topology and from there we want to go to our error inspector the error inspector allows us to to view our errors and and it gives us some tools for fixing them so I don't really love this pink color but I'm just going to leave it for now and notice across the top of our error inspector window we've got our topology here listed and we can validate it okay so we're going to click validate it runs and it returns to us some errors you can see the errors or are these red areas okay so if you select an error here I'm gonna move this over a little bit or maybe have resize it I can you'll see you're uh I'm just gonna you know move it over here for now no that's what I wanted to do okay so you can see when you select a topology error here after validating it shows you the errors it shows you the errors here it previews it you can look at the details and it tells you the rule that's violated and you can even look at a fix for it okay so before we start fixing these things it's important to note that you can mark errors as an exception a good example of an error this is an exception in a Rhodes data set we often apply a rule that says lines in the Rhodes data set must not have dangles and what a dangle is is the end of a line that doesn't connect to another road so if somehow a road was not snapped appropriately to the road it intersects it would show us those as errors now in a road network roads have to be properly connected so you can do routing through a road network but a cul-de-sac with a dead end or a dead end road that does not connect to another road is an exception to that rule so you can mark exceptions okay so what we want to do here is I'm gonna select this first must not have well we're not going to mess with this top must not have gapps yet let's start with this bottom one because it's this little one that we zoomed into and if you select it you can actually zoom to it here you don't have to zoom to it in the map because you can see it in the preview here but I like kind of like working it with it in the big map - so this is an overlap it's if you remember it's an overlapping polygon and if you want to see it you can turn off your your topology there and I could select this polygon you can see that overlap if you remember from the previous video this polygon is underneath this top polygon so you don't see its boundary it's hard to tell that it overlaps so I'm gonna turn that back on and clear my selection alright and so let's go see the options for fixing this okay so I'm gonna make this a little bigger so you can see a little bit bigger so we can create a new feature from that if we created a new feature it'd be a new polygon there there is no polygon there in between these two ems layers you could remove the overlap if you do that it's gonna it's gonna end up I just clicked it it's gonna create a gap so then if I validated again it would violate the other rule so I'm gonna undo that and select that again and in this case we're gonna merge this and when you merge features together it wants to know which which polygon you want to merge it into and in this case we merged it into the polygon above it because that's the error that was overlapping I clicked I clicked it - to merge it before I met - but essentially I merged it into here and you can play with those fixes to see what you think's appropriate now let's look at this one for must not have gaps so when there are gaps I'm gonna zoom in too it okay we saw this gap and if I turn off my topology you see there's a there's a gap between the polygons and and that happens sometimes during data creation when when the technician doesn't appropriately build data so that there are coincident features between adjacent polygons and so the only fix for that is to create a feature if I click create a feature it creates that feature now that we don't really want either so you would need to merge that little polygon into one of these two polygons and if I drag a selection so that it just barely touches both of those I get both of those polygons selected and in this case I'm gonna merge that little sliver over here in the e8 see which one do you merge it into well you have to determine which one you think it goes to oftentimes if it's such a small sliver it doesn't make that much of a difference but try to merge them into the appropriate one and so we've selected those two polygons and on the tool section here of our edit tab I'm gonna merge now the merge comes up and it always wants to know which attributes or do you want to retain when you merge two polygons together so this little sliver polygon I'm clicking on and it's it's flashing it doesn't have attributes for the ems layers it's a it's got no attributes we want it to keep the attributes from the big polygons so we want to merge it into this big polygon and keep the attributes from that okay so I'll click merge and we'll just see that happen merge features completed now sometimes the graphics just don't update as quickly as you'd like so you have to kind of click and it it gets shows that it goes away okay so we just found that error we created for each one you merged it in okay so this final rule I was not expecting to see at all that not this final rule this final error I'm gonna clear selection there and I'm gonna select that rule and somehow this whole outer part has some kind of gap included and we can preview it and maybe I'll just use my scroll mouse to zoom into it I'm not real sure what the deal is with that error but let's let's try to fix it so what kind of rules do we have to fix it well we can create a feature or we can mark it as an exception it would take a good bit of investigation to see exactly why that's coming up for now let's just try to create a feature and see what it does so I created a feature now if I go to my attributes for this layer attributes that feature I'm gonna try to layers let's go back to attributes sure well my attributes aren't coming up here am I missing them somewhere let's remove ah close that attributes there close that pop-up and oh that's them I'm still in the merge okay so now let's uh let's go back to attributes okay so I don't have a layer choice and that's why the attributes are not coming up well I do have one there it still wants to know what layer here so let's pick EMS Topa all right and so this is these are the attributes for EMS topo and what I'm looking for is a polygon that doesn't have any attributes because that new polygon that got created obviously doesn't have attributes and so the deal is it looks like when I flash it that's one big polygon underneath all these other EMS polygons and so that was definitely an error and in how this data was created ooh actually it created a polygon on top of all of the other ones if you notice I'm gonna turn off my primary roads you've still got the labels so it generated this polygon that covers all the other ones so somehow there was definitely some weird error in there that ended up generating that big polygon so I'm gonna right click that polygon that got created and select it and then I'm just gonna delete it and you see it goes away and it shows you those EMS layers again so now I could validate again now since I made some edits let's just look at the dirty area again so it's it's got a it's got a big ol dirty area again cuz I made some edits it need to be needs to be validated again and when I validate I've got another error so if I click that error I don't see it preview it here that is an odd error and if I create another feature from it look at what it did that time it did created another polygon so I'm gonna try to select that polygon and this time I'm gonna select it like that let's clear the selection let's select that polygon that got created right-click and select from the attribute table and I'm gonna delete it again I'm gonna validate one more time and see what it does and it's got another error and it has to do with create one more feature and see what it does it created that whole thing again all right so in this case this error is a little bit hard to figure out what it is without some some pretty significant research so what I'm gonna do we're gonna use this opportunity I just deleted it again we're gonna validate one more time and I'm gonna use this opportunity to mark it to show you how to mark as an exception so under the fix I'm gonna mark as an exception you can always clear the exception later and come back to it but I'll just mark that as an exception so now I'm gonna validate again you can see it's an exception and that rule will stay there but there should not be any dirty areas now okay oh my topology was turned off that's why I wasn't seeing those errors when when I was just trying to look at it every time I revalidate it so that's an interesting example and a good chance to mark something as an exception all right okay so let's save your edits you fix those edits no again the the important takeaway is that some of these errors like slivers and polygons and when a point doesn't quite connect to the end of the line they can be so small that you can't see with the naked eye there could be hundreds or thousands of them so these tools are a great way to go through and validate if your data meets some standard rules for how your features connect and if they don't show me them so I can so I can fix them all right okay so I'm going to just save my edits you can save yours too and you can you can play with this some more as you go sure save all my edits now let's go over here to this more topology stuff tab this one's gonna allow us to look at another example but before we do that I want to look at the map to policy not the more to policy stuff so move over to the map topology map now we want to activate a geodatabase topology but before we do we need to go add our feature classes to the topology and and give it some rules so if you remember we uh we only added the ems layer to this feature data set now we want to add the sewer pipes in the sewer structures this is going to give us a good opportunity to see how the feature classes spatial references have to match exactly with the feature data sets this EMS layers from the county these layers are from the metropolitan Sewer District so they come from different sources so I'm pretty sure they're both in state plane but the definitions behind some of these coordinate systems can have some very slight variations and even a slight variation will stop it from being added to the feature data set so I'm gonna copy sewer lines or sewer pipes sorry sewer lines sewer pipes and I'm going to attempt to paste it in this feature data set and it looks like it's running fine but eventually it pops up an error and essentially it says the spatial reference says do not match okay so the easy way to fix that is to export a layer into a feature data set when you copy and paste they have to have the exact same spatial reference but when you export right click export to a future classes to a geo database it's gonna project that data to match the spatial reference that the feature data set during the export process so we're gonna take the sewer pipes and we don't we wanted to go to the database but we want them to go to the feature data set within the database so if I go to my databases here I can select that feature data set databases feature data set I could have drilled down through the directory structure to find that too okay so that's going to take this and it's going to export it into here and take on the the coordinate system information okay so it's converting and again it can't the database cannot have two feature classes called sewer pipes so this one comes in and it renames it sewer pipes one so we're going to do the same thing here and rename it certain types Topa press enter let's just so it's a little more descriptive now again you would really not want to keep the sewer pipes because you don't want two copies of it now this time we also want the sewer structures to go in there and it will not copy pasted either but instead of right clicking it and exporting i'm gonna come from the other direction and i'm gonna right-click my feature dataset i could right-click the database but since i wanted to go in the feature dataset i'm gonna import and i'm gonna import a feature class so you can import from the feature from the database or feature data set or export from the feature class the input features are gonna be which one did i do first I did the pipes first so I'll do the structure system and doing it this way allows you to give it a name so you don't have to go in and rename it or worry about it having the same names underscore Topa if I tried to call it sewer structures it would throw an error on the import process you can drop fields and stuff like that like we've seen earlier in the semester but I'm just gonna go on and I'm gonna run this okay so if I go back to my catalog I can now see that I've got these feature classes in here and in my I should be able to modify this geo database feat geo database topology okay so if I right click the geo database topology and I go to properties if you remember it's got a name and a spatial reference and all that and it only had I only had it participating in this one this feature class first but now there's more feature classes in the in the featured data set so I'm gonna check these two and tell them to allow them to be part of the topology all right now if we think that the if we think the the structures are the most accurate and we don't want them to move we want the pipes to move before the sewer structures move we can assign a couple of ranks and we can then tell it that the sewer structures have a higher rank than the sewer pipes and that allows features when things move based on features moving if they're within the cluster tolerance setting this rank tells you that you want your sewer pipes to move to match the sewer structures rather than the other way around and you just do that based on what you think the accuracy of your data is and what we're assuming here is that the sewer structures or the manholes were surveyed in with a survey grade GPS and are the most accurate all right so now let's go to the rules and we need to add a rule so remember this rule worked within a single feature class now what I want to do now as I want to say I'm gonna pick the sewer pipes I think I wanna you can all at you sometimes you can do it either way let's try the structures first and I want to say the sewer structures and I'm gonna pick must be covered by the endpoint of a line okay and so what this is saying is the end of the future class that we choose here the end of the line must be covered by the endpoint so a point this point must be covered by the endpoint of this line essentially what that rule says is that they have to be snapped to the endpoint of the lines the manholes alright so there it is so this rule is between multiple feature classes I'm gonna click OK here and it applies the changes to my topology rule and now we've got our unless let's remove these feature classes from this map because they're not the ones in the feature data set participating in the topology okay they're the original ones so I'm gonna remove them and I don't know how that super structures got in there I'm gonna remove it too and when I add this topology back in it's gonna add all the feature classes that participate in the topology and I wanna I don't care about my EMS topo it's in that topology but I don't really care about it and I'm gonna make these points look a little bit different by clicking on it and making it a solid point with no outline around it and if I go to the properties I'm gonna make it smaller and I'm gonna make it green like it was another map okay and maybe make my sewer lines a black this is not required but I like to make things look a little bit like I like them to look okay alright so the way you build these rules will return the error on one or the other of the future classes so let's validate this and it's going to return a lot of errors in the in the data set okay now if you can see the way we built this rule it's returning to us the points as errors there's a different rule that you could build in a reverse way that would show you the lines as the errors and most of the rules are like that so let's zoom into these guys and they show you that these are errors and you could use this to zoom in and look at them but I just want to kind of zoom around a little bit and look at it myself and see what I think all right so what's the deal with these so this line right here is not split along those manholes so even without using these rules I could come in here and since I have that selected I could go to split that line and if I snap right to that point it splits it right where that point is okay and then I could split that one and then I could split that one and split that one so now if I clear my selection and I go back in and select nope I miss that one but that one's good and that one's good so let's do this one too and I'm gonna split it right there Oh see you valid I think that point maybe off of the line did that work don't think it is so I'm gonna clear my selection and try to select again so I think that points not right on the line we'll come back and look at that one again so watch what happens now when I validate it should remove those two areas are those two errors on those manholes it should remove that one but that one's still going to be there so I'm going to validate and you see these errors went away that one's still there so that may be for another reason okay so let's select this one so now I've got this error selected and this guy to fix it so the only fix for that is to delete the feature all right now we don't want to delete that manhole so a lot of times the fixes in here aren't exactly what you want to use and you don't have to use them you can go in and fix the errors anyway you think you can like I just went in and split those lines it was obvious to me that you know that line doesn't run right through that manhole without connecting to it so I fix out one now this one we don't want to delete so I'm gonna come in here and see if I can figure out what's going on with it and I'm gonna turn off my topology that shows the errors and I'm gonna grab that point and I'm gonna move it and just see if I can get it to snap to the line it's almost like it was not snapped to the line so if I grab it oh it's not letting me so now it's kind of participating in the map topology kind of thing I don't want that so I'm gonna undo that so this is an interesting issue I'm not sure why that wouldn't let me split that at first but I'm going to come in and try to split it again and see if it split it did it split it to clear the selection and so it did split at that time and I don't mean to be doing that alright so remember that was an error there I'm gonna clear my selection and I'm gonna revalidate and that should remove that error because I split those lines so that now they're on the endpoints of that line and that did fix it okay so there's a lot of errors right so this is a good way to find errors in your data there should be some errors like this one you know this one's not connected to any lon maybe that's an abandoned manhole that's there's no bond going to an e more it's been decommissioned so that would be a good example of one you could select and you could mark as an exception okay so I'm just gonna mark that as an exception I'm just assuming that it's an abandoned part of the of the sewer system okay so that helps us to to see some errors and to and to fix some now you can look there's there's a lot of errors 35 errors that for some reason or another aren't correct here's some that aren't connected are those all exceptions how about this one is it just a batch of that one's probably just off the line it's just not within the cluster tolerance and it's hard to tell yes see that one so I just found that one so if I you know that again is that and if you are if you look at the fix for these I mean the fix is gonna be to delete it every time and we don't want to do that we want to move that whoops to the end of the manhole choose features there I'm going to turn off my topology so I can see it so I'm just gonna grab that and I'm gonna snap it to the end there all right so I moved it now that becomes a dirty area again validating get rid of the dirtier but when I validate you'll see that's not an error any longer okay so those are some that's a little bit on the geodatabase and the Judah database topology rules and fixing errors remember you can use their fixes or you can just fix them and then revalidate I'm going to have a small assignment for you to do soon and we're gonna probably use this data where this data are to feature glasses their address points in a building's layer and usually you think of every building I'm going to remove the outline color and make this a different color something like that and I'm going to change this to the address points layer typically every building has an address point and so there we could build a couple of different rules we could build a rule that says show us any address points as errors that are not in a building or we could have it show us buildings that are don't have an address point so again you can build the rules kind of either way but that's a rule that says they have to be contained points must be contained in polygons or polygons must cover point and rules that are those might not be the exact wording of them but uh I'm gonna write up a short exercise I'm gonna it's just going to give you the very basic information on on doing that and you're gonna have to create a feature data set the topology the rules and and validate them so look for that coming soon if you have any questions about spatially related features and topology map topology editing spatial related features or geo database topology please don't hesitate to ask alright thanks for listening

Channel: Pete Kennedy

Views: 3,589

Rating: 5 out of 5

Keywords: Esri, GIS, A-B Tech, Topology, ArcGIS Pro, ArcGIS, Geodatabase Topology

Id: l6Jc66WzhT8

Length: 47min 48sec (2868 seconds)

Published: Wed Mar 04 2020