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5

First, let me say that I share your frustration with the inability to set flow direction where there is a split with multiple sinks. As far as I can see, you have set up your dataset, layers and network properly. The explanation that I received is that when there are 2 or more sinks on a common junction, each sink potentially has the ability to draw flow ...


4

Try finding all polylines where IGeometryCollection.GeometryCount > 1. I think the example for calculating vertex count could be adapted to do this with the field calculator.


3

From the look of your screen shot it looks like you have used the utility network analyst toolbar and the Trace Upstream option? So... not ArcHydro? If this is correct then click on the down arrow next to the word Analysis and select options. Under the results tab set results format to selection. This will select the polylines and you can compute the total ...


3

Short answer to the question "Can we create relationship classes based on a geometric network?" Relationships yes, relationship classes no. Long answer: A relationship class as defined by ESRI deals with how attributes inside fields relate to each other in two or more tables. A relationship class can be one to one, one to many or many to many. It can be ...


3

The areas you are looking to create are called "subwatersheds" or subsheds. You can use the "Batch Subwatershed Delineation" tool in ArcHydro under the "Watershed Processing" menu. This will calculate subsheds from a set of points you define. The other input is a flow direction grid. This is a raster where the value of each pixel represents the direction ...


3

I found a procedure to do this described step-by-step at the ArcGIS Discussion Forums. I recommend that you use that to perform each step manually first, and at the same time use Copy Python Snippet in the Geoprocessing | Results window to start building the Python script for automation. I would use Python by preference but it may also be amenable to ...


3

After making a lot of testing, I found that the most accurate way to detect geometric network actions(such as connect, disconnect) in an IObjectClassEvents::OnChange event is to use the interfaces IRowChanges and IFeatureChanges to determine if something changed. Private Function NetworkConnectivityChanged(ByVal obj As ESRI.ArcGIS.Geodatabase.IObject) ...


2

It's not going to be as easy as you expect. Firstly you need a data source. Your best option for this is OpenStreetMaps' Database. But if you take the entire world, the data is in 100s of GBs. Secondly, you will need a source for your cities. You will need a polygon source, which indicates the boundary of the city, so that you can then select the streets ...


2

I used Google to find that there is an issue with using it as a plug-in to ArcGIS and AutoCAD at the moment: Temporary Notice Unfortunately, pending discussion with ESRI and Autodesk over use of sDNA within ArcMap and Autocad, plugin functionality is disabled for the moment. Fortunately, it is still possible to use sDNA Standalone to ...


2

At the web site I found by using Google? You need to register to download it.


2

When working with Geometric networks I find it is best to specify either a source or a sink not both. Here is Esri help section on this topic In utility network applications, knowing the direction of flow along network edges can be essential. The commodity that flows through the network—water, electricity, and oil—has no will of its own. The network ...


2

Yep, turns out I wasn't honoring the wisdom of the beginner's mind and I jumped right to an assumption that my problem was way more complex than simply not having run the Set Flow Direction tool. Entries in the attribute table of the NHDFlowline file suggest that "WITH_DIGITIZED_DIRECTION" is the right parameter to go with - and it seems to check out ...


2

There are errors that one can get due to several wrong bits. Please refer to the help page Identifying geometric network build errors. Most often these errors have to do something with errors in features' geometry. I would start with: 1) Click Customize > Toolbars > Geometric Network Editing. The Geometric Network Editing toolbar is added to ArcMap. 2) ...


2

I'm sure you're aware of the nature of Open Street Map - it's a user collected and edited resource. If you're going to use this kind of information it would be largely down to you to fix these - and in the spirit of things update the information! If you want a relatively clean network for analysis straight away, I'd suggest TIGER. ... but I think you'd ...


2

If the end points are not marked as such, you will have to find a definition that can unambiguously identify an end point. Depending on your geometry, that may be next to impossible, because an algorithm cannot tell whether the points y | A B C D +----------x represent a simple line A-B-C-D or a polyline A-B C-D unless you have a clear criterion ...


2

This is a fairly standard Computer Science algorithm. I'd think it uses something like the optimal algorithms described on this page about looking for loops in a linked list.


2

A polyline is closed if from and to points are the same. So you could test this in a new field: field calculator : Python codeblock def IsClosed(shp): if (shp.firstpoint.x == shp.lastpoint.x) and (shp.firstpoint.y == shp.lastpoint.y) : return 1 else: return 0 result IsClosed(!Shape!)


2

See if these links help you out in your search: GIS for Gas GIS for Pipeline


2

For each line, you could create the from point using "feature vertices to point". Then you get the spatial join between the man hole and the from points (with INTERSECT), with a join_count field. If you have one intersect, this is OK, zero intersect means that you you don't have line starting from your mahole and 2 intersect mean that both lines end in the ...


2

I don't understand exactly what you're asking. Read this to learn about the different replication types: http://resources.arcgis.com/en/help/main/10.1/index.html#/Replication_types/003n000000t6000000/ A checkout will either be a personal or file geodatabase. It should look and feel the same as editing from an SDE database. It's just a copy of the SDE data ...


2

You can use Trace Geometric Network gp tool and accumulate in_edge_along_digitized_weight {An edge weight that is used as a cost for traversing through an edge along the digitized direction of that edge. The weight must already be defined for the given geometric network} - and - FIND_UPSTREAM_ACCUMULATION. use the accumulated value for the index


1

A node and a polygon are mutually exclusive defines although a polygon could potentially be composed of nodes as related by interior and or exterior edges. A shape file already has topological relations and can consume routing applications, so networks and nodes are already present. You are trying to reinvent the wheel perhaps? routing can consider an edge ...


1

you need to use Trace Geometric Network (Data Management) Geoprocessioning tool and choose your barriers features as a barrier layer input


1

You don't need to worry about this. Working with the checked out geodatabase is not different than working with a non versionned data: all the work is on the side of the default version. What you need to care about is to make sure that you don't have a conflict between your ArcGIS release and the one where the data comes from (see here). If you version is ...


1

Ok a lot of questions, so I will start with a general hint: What you are looking for is just a 'routing graph' for a geodata set (here: OSM). As you say this graph needs to fullfil certain properties (as connectivitiy, level of detail, ...) but IMHO your cell approach sounds a bit complicated. There are existing solutions to turn OSM raw data into graph ...


1

A way of doing this is to cycle through your man hole dataset, use each point to select the polylines then test if your man hole point equals the last point of the polyline, if it does then the polyline must be flowing into it.


1

This is a known problem and there is an ArcGIS 10.1 SP1 for (Desktop) Geometric Network Reconcile Patch to resolve it.


1

I realize you only have access to arcgis, but for future reference I'd like to add MikeUrban by DHI. It works as a large extension on ArcGIS and requires a Standard license. It can model pipe flow in all and every pipe, wells, pump stations and almost every other feature you can possibly need in a pipe network. It can also model overland flow to a drainage ...


1

Set the volumes as weights and use FIND UPSTREAM ACCUMULATION This trace determine the total cost of all network features that lie upstream of a given point in your network. it requires a weight be defined for the trace and flow direction to be set on the geometric network. - All the features upstream of your flags are displayed, and the total cost of ...


1

You tag this question as a python question so assuming you are using 10.1 then looking at the page on Polyline geometry in the Help file it shows that Polyline has a method called getPart which returns a list of points. If you know which end your intersection point is then its just a matter of stepping through the list.



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