ArcGIS Topology Demo

in this video I'll demonstrate how to work with map topology and geo database topology inside of ArcGIS desktop I'm working with merging 10.4 so this is a sample data that I have there's a topo demo folder here and you will see in that folder there's a geo database and there are some shape files as well there's actually in the geo database there's also a feature data set and in that feature data set there are some feature classes so these feature classes we've got duplicates of them down here as the shape file type format as well so the sewer pipes here is the same data down here sewer pipes just in different formats I'll put some data up here in this in this geo database feature dataset so that we could work with geo database topologies so before we work with geo database topology we're gonna give a quick look at some some of the basics of mat topology and so a thing about map topology we could use feature classes out of a geo database to to to work with map topology within an edit session but we can also use shape files so we're gonna use shape files in this example it's a nice thing about map topology is that it's available at the basic license level of ArcGIS and also you can can model spatial relationships between features within different shape files or within the same shapefile using map topology by computing coincident vertices on the fly and the in the RAM so map topologies nice for those reasons so we're gonna go to arcmap here and I've got arcmap in a separate window but I just wanted to drag and drop a couple layers over so let's just start off with say the MSD I think I want to look at maybe the municipalities okay so if I drag the municipalities layer over to arcmap within this one your class there are coincident features and remember coincident features means features that fall within the cluster tolerance and so if we were to start editing here on this shapefile and we've got a polygon here and we also have a polygon here so we've got two polygons and they're adjacent the line between them should be coincident meaning that it's part of the definition of this polygon and of this polygon so if I double-click this polygon you'll see double clicking it brings up what's called the Edit sketch and you can see these vertex vertices that make up this polygon we should see those exact vertices duplicated as part of the definition of this lower polygon so if I double click it you'll see they're the same so if the boundary of the municipality here changed say some land was annexed possibly this is the city of Asheville so if we were to an act some land down here we could move the boundary down here during a regular edit session using the edit tool if you you go to move of artax it doesn't move the vertex in the other polygon it moves a single vertex I'm going to ctrl Z to undo that operation and you'll see that it just moves one vertex and there's actually a coincident vertex directly under it so I'll undo that again we can also reshape this polygon using this reshape feature tool on our editor toolbar and I'll start by just snapping to it and just click click click click click and reshape it and notice it it doesn't move features vertices and other features that are coincident with the vertices that I'm that I'm editing so that's not a big deal if you're editing the outside here because there's no coincident features with it so I'm gonna undo that again and and look at how we can we can manage this coincident line using a map topology so I'll turn on the topology toolbar it's already on I don't see it the topology toolbar was off on this screen over here I'll bring it over okay so the topology toolbar we use this topology toolbar whether we're working with map topologies or geo database topologies when you work with the geo database topology the geo database topology has to be set up first in our catalog using the wizard that creates a topology you specify things like the feature glasses that will participate the ranks the rules all those properties and then once you bring it into arcmap you work with it with some tools on this toolbar if you're working with the map topology there's nothing to do before starting your edit session and coming to start working with this toolbar you go to this tool to select a topology and since we don't have a geodatabase topology we don't have an option to to work with the geo database topology what I'm going to do is tell it that this one layer is the only layer that participates in the topology and what that does is any features like those to those vertices that were coincident any features that are coincident and remember that means they are within the cluster tolerance any features that are coincidence features vertices they will act as a single unit during editing so if you look at this options drop-down you'll see the cluster tolerance it's a it's a small number the units are in feet those are the coordinate system units stored with this data and so it's three 1,000th of a foot this is a small smaller distance so I'm going to just click OK and what that does is builds a topology cache that stores the information before coincident features and vertices so instead of using this edit tool we use the topology at a tool and remember from our discussion that what that does is it it turns arcs and lines and the edges which are shared between features so this edge is shared between these two polygons and it turns by and it turns vertices as well so if I double click this line and I move a vertex it should move any vertex that is coincident with that one so if I move I need to click here again to refresh the display and you see it moves them both so the same with the reshape tool if this this land down here was annexed into the city based on some road we could we could reshape this to make it to make it more representative of the new annexed area so let's just add one other data set here that'll that might help us to to decide how to how to draw this draw this new area in and so I'm gonna go to some Ashville data I have and and within a Nashville database I've got some some streets data so let's see city of Asheville I'll probably use the whole buckin County not sure why everything is sorted by reversed okay so let's just say that now we've got some street data and let's say that we wanted to come we annexed along this road and then it cuts across a field to this corner okay so so let's uh let's select this line using our topology edit tool and I want to reshape this edge and I'm gonna actually reshape it based on the shape of this line here because I know that the the new and next area goes down the center of that road and so I'm gonna actually take this a little farther and I'm gonna use this trace tool and I'm going to well I'll start with just the reshape edge and I'll start by clicking where I want to start reshaping it and see how it's it's tracing now let's just bring it down that road and we're going to stop it here and then I'm going to draw a cross using the straight line segment and what this will do is actually change that boundary to follow that road so now you've got this vertical integrity so of a trace that that goes down some other data you have so so that's using this tool let's turn off the streets and you should see that so now we reshape that whole area and if I if I look at the vertices of that and the vertices of this that's a that's a good way to manage that that shared coincident boundary between those polygons now this also works with with other types of features and and beyond a single feature class so let's go look at our our data for the class and this demo and I'll make this data available to you and let's add some sewer pipes and some sewer structures so in a sewer system sewer sewer lines usually are always end up at structures things like manholes so if if out out there on the ground you wanted to dig up a manhole and move it you'd also need to move the lines that feed that manhole so what I'm going to do is I'm going to go now that I've added these two feature glasses I'm going to tell it and I could leave this is part two if I wanted to leave the municipalities in it I could have added them all to begin with what I'm saying is that any features even within different layers that are coincident will move at the same time so using my topology edit tool there if I select that manhole right there and I'll move it if the ends of those sewer lines if they are coincident or within the cluster tolerance they should move with it and it does so that's another example now during a regular edit session if I were to move that manhole so using it my regular edit tool having not created a map topology and not using the map of the topology edit tool if I moved that manhole it moves by itself I could then double click this line and move this vertex up there and I could double click this line so it's not that it's not possible in in many cases it's just easier to manage it in a topological kind of sense so so that's me that's math topology I'm gonna stop editing and I'm gonna not save my edits and we're gonna these are just shape files so I think this will still work so in our in our geo database here I'm going to create a topology a geodatabase topology in my MSD feature data set so I'm gonna right click here and it starts to draw everything that's in this feature data set I'm gonna right click and I'm going to make a new topology and so here's our little wizard here so this wizard helps you build a new topology a topology allows you to model the integrated behavior of different data types for example include some examples include modeling adjacent land parcels or soil polygons and we've seen some other examples so we're just gonna click Next here I'm gonna call this one MSD topology that's okay because so we'll call it the sewer topology how's that because we're going to model the sewer lines we've got a Koster tolerance very similar found the exact same to what we saw when we made the map topology it's based on the original precision of the data and we usually take this default the cluster tolerance is the distance range in which all vertices or boundaries are considered identical or coincident notice down here it says the default value was based on the XY tolerance of the future data set so you'll see XY tolerance is it as an additional to cluster tolerance all right so I'm gonna say that my sewer structures and my sewer pipes are going to participate in this topology now the ranks allow one to move more than the other and I know that we GPS these sewer structures with the survey grade GPS they're really accurate so I'm going to give it a higher ranking of two and so the sewer pipes the end of the sewer pipes if they are or within the cluster taller or they they should move to snap to it if they're within that cluster tolerance so let's click next and we need to add a rule and there are lots of rules depending on the types of geometry that you've chosen you'll see different rules that work with different geometries we want the the feature class the features of the feature class we want the sewer structures to be covered by an endpoint the endpoint we could have them improperly inside if this was a point in polygon rule be the same coincide with we want it to be covered by the endpoint of a sewer pipe okay covered by the endpoint of a sewer pipe so what this is gonna do and so there's a manhole that's not on the end of a sewer pipe it's gonna show it to us as an error so something I'll mention before I go on feature classes like the sewer pipe can be further classified within the feature class using something called a sub type and you're gonna see sub types next week and a sub type is an advanced functionality in the geo database and again it allows you to further classify features within a feature class in this case our feature class our sewer pipes and so within sewer pipes if you do this drop down you'll see there's different types of sewer pipes so again it allows us to classify the sewer pipe by a further classification in this case the type and so you could say that a certain type of superstructure has to be on a certain type of sewer pipe to further constrain and control how this works if you have some type setup now subtypes we're set up on this data by MSD and I'm just gonna not choose a subtype so I'll click OK I'll click Next it tells you the name the cluster tolerance the Z tolerance some other properties click finish and it's it goes to work building our new topology so when it finishes creating the new topology it's gonna ask me if I want to validate now validating you usually want to validate the whole data set but you could zoom into a smaller area and just validate that in this case I'm gonna go in and validate it while it validates if you if you wanted to you could load it into arcmap not validate the whole thing and then zoom into small areas and start validating it takes a long time sometimes to validate and this in this case it did not so if you look at your sewer topology it symbolizes errors so I can see there are some errors here and if I look at where my sewer structures are you can see that maybe there may be there were sewer there they are where the sewer structures are so if I right click this topology I can look at it and under the properties I can even generate a summary of the errors it you're under the properties of the topology that has the rules and the feature classes other information and I can look at the errors and I can see right off the bat there's 617 points in the sewer structures layer here that are not on the end of honest so let's go look at some so I can I'm gonna insert a new data frame just to have a clean slate to start working on here and I'm gonna I'm gonna grab my sewer topology and drag it over here and it's gonna ask if I want to also load the feature classes to participate in this sewer topology I do and you usually do and you can see the the topology is in the map and it's symbolized like anything else you can actually change what these look like if I don't like that color I could symbolize it whatever I want I usually leave it the color they are but uh so you can control things like that so let's uh look at some of these errors so let's look at our topology toolbar again okay I need to start editing and I'm gonna pick my geo database topology since I have one and now I've got a lot of options you can do things like look at the error inspector this error inspector allows you to search for for errors within an area within a certain rule I'm just gonna search now for all of minute it shows us all and since we've only got one rule they're all the same thing so it's pretty easy just to kind of zoom in and look around and see if we think it's it is really it there really are errors and so if we uh it would probably help to drag this topology error below go see how the topology error symbol it uh it covers the manhole so let's drag it below it so we can see okay yeah looks like there is a manhole there and let's turn off the turn off that and got a really zoom in and in that case it looks like well if you get close enough then that's not a very good example let's look at some others and see what else we can find the one I looked at earlier was a great example so let's uh let's look around a little further alright so here's another one that one might not be a good example either you you you let's just keep looking sometimes the error is kind of hard to distinguish just from even looking at it with the naked eye you can obviously see these points are not connected to any sewer lines so why are they there so let's uh let's look here at this we could fix this error so what do you do is once like this and you you may delete the feature if it shouldn't be there or you might mark it as an exception so either there's a pipe that goes out there to it that you need to add or you would mark it as an exception so I can right-click it and I can delete it if you if you determine that that structure is not there you can delete it if you think a pipe goes to it you can draw the pipe to it or you can let's just mark it as an exception and I'm going to mark this is an exception to let's just say this is some old historical structures that they want to leave in the database but they're no longer connected to the system of mark them all as exceptions and then I can validate in my current extent again and you see they don't come back as errors so I've validated after our marketing exceptions and they didn't come back all right so let's see if I can find a better example some of these you well let's uh let's turn this off and since I'm editing let me just grab this right here this man holding I'm gonna move it yeah and I'm gonna snap it that looks like it looks like all that's coincident to me let me let me turn this back on now that I've moved it away and recent Apted validate possibly you you well this demo didn't go very well because of this let's uh let's grab mark topology edit tool and and if I move that if they're coincident you you so if I moved this manhole see how that line moves with it I'm not certain why showing some errors here let's uh well let's uh let's do this let's research for them let's search not in the invisible extent let's search everything I'm gonna right-click one here and I'm going to zoom to it that is that one okay so that's definitely an error because it definitely does not connect what I was expecting to see from these other ones was an obvious gap between the manhole or the structure so that's the one I just zoom too and if I right-click it the onion to fix it is to delete it I could reconnect them let's try that let's just do it this one too I'm gonna move this to there then I'm gonna grab oh I got it that's where those errors are from my apologies so these errors are here because it's a big long line going through it they're not on the endpoint of lines so how do I fix that I'm gonna undo that move there I could split each one of these so I've got a line selected and I could split the line right at the manhole so now there's one that ends there and starts there I could also split this one now in this case there's actually a a tool and the geoprocessing tool box that you can have it automatically split lines based on points that are on the lines now the problem is if if the point was just a little bit off line it wouldn't work so let's re validate in this area in our current extent and you see those went away because they now are the end points of lines also not that one okay so that's where a lot of errors are in this database from the points are just dropped on top of a long continuous Y so I'll validate again and you see it fixes that so that's a small example of a geodatabase topology it allows you to the big difference is this rule-based and it allows you to actually look at a lot of data and find errors in it so everywhere that a manholes not properly on the end of the line it allows you to evaluate the overall integrity of data sets and if if you had a lot of data with small mistakes it's a it's a valuable tool this is really kind of part one we're gonna have another editing video when we get into our campus project that's going to show us other ways of creating topologically topologically correct data during editing using other tools like the autocomplete polygon tool and the cut polygon tool and we just saw the split tool that's useful as well so we'll have some more editing demo and exercise as we as we get into our campus project

Channel: Pete Kennedy

Views: 8,095

Rating: 4.8367348 out of 5

Keywords: geodatabase topology, topology, map topology, arcgis, gis, A-B Tech, Asheville

Id: tjLVeqReUng

Length: 26min 44sec (1604 seconds)

Published: Sat Feb 18 2017