To merge features based on specified attributes.

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2
votes
3answers
1k views

Want to dissolve adjacent polygons but no common edges

I have a bunch of parcel data, I want to join the polygons basing on the same owner name. Even they are not touched, I want merge them together, such a 100 feet tolerance. The purpose is to show the ...
1
vote
0answers
111 views

Why doesn't dissolve finish? It just stops without error message

I have a shapfile of the whole UK that contained Postcode area, district, and full postcode. I was going to try and dissolve the regions into seperate business areas by joining a lookup table that ...
0
votes
1answer
343 views

Dissolving shapefile python script not working, syntax help please

I do not understand why this simple script won't work. I can get it to dissolve in model builder but not from a script that I run from inside the map document. My output results are 4 polygons, just ...
2
votes
0answers
243 views

Problem when executing Dissolve method in ArcEngine

I'm always having a problem in GP.execute() when trying to execute this method. Here is my code: Friend Function DissolveFeatures(ByVal pInFLayer As ESRI.ArcGIS.Carto.IFeatureLayer, ByVal ...
2
votes
1answer
375 views

How to measure the area of polygons within a fishnet

I am currently trying to measure the area of polygons within each square of a fishnet. The aim of what I am doing is to work out the proportion of different agri-environment schemes by 1km squares. ...
4
votes
1answer
123 views

Automatically build branches of a river network?

A small non-profit, specializing in fish habitat restoration, has asked me to link a spreadsheet of field notes to their gis. What we have is: 1) A spreadsheet of field notes for small fish streams. ...
5
votes
1answer
461 views

PostGIS - Why are my ST_Union results (stored in a new table) outputting as points and not polygons?

I've decided to move to PostGIS to merge polygons rather than spend hours doing in in QGIS. However, I'm hitting an issue where the results of an ST_Union query are being stored, or at least outputted ...
10
votes
1answer
5k views

Merging adjacent polygons in shapefile that has been split at tile boundaries?

I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile. This is ...
2
votes
1answer
168 views

Dissolving stream orders using Python rather than VB script?

I've been trying to dissolve streams, using orders programatically and I came across this VB script. The reason is that if I use ArcGIS dissolve, it merges the confluence of the same orders. I would ...
3
votes
0answers
165 views

How to achieve better Dissolve results?

I applied the Vector>Geoverarbeitungswerkzeuge>Auflösen (Dissolve) on a zoning plan (see picture zoning plan). I used the attribute village name as the dissolving criteria. The resulting geometry for ...
1
vote
1answer
71 views

How do I create multiple polylines from single polyline that consists of disjunct sections?

My goal was to create a network of polylines in NHD plus based on start and end points associated with sampling locations. Dissolving by stream name was my first step and has worked just fine for ...
2
votes
1answer
428 views

Why does Merge then Dissolve return ERROR 000732: Input Features: Dataset … does not exist or is not supported?

I'm not sure why I'm running into this problem. I thought it might have something to do with the merged file being locked or open, but I don't see a "LOCK" file being created in Windows Explorer. ...
3
votes
1answer
281 views

How can i merge lines with same name and intersect each other?

I have shp file with 50k lines (roads). Many roads have same name like 'high road' . some of them are the same road (they intersect each other) and some are located in different places of the city. I ...
3
votes
1answer
131 views

v.dissolve to multipolygon

Using v.dissolve in GRASS, I'd like to get a multipolyon as a result. However, I end up with distinct polygons with the same 'dissolve value.' For example; lets assume I have two polygon features ...
5
votes
1answer
1k views

Dissolving specific polygons inside SearchCursor with Python in Arcmap

I have a layer with catchment polygons. For those that are smaller than a certain size, I want to merge with an adjoining polygon (namely the one downstream). In the attribute table I have a GridID, ...
1
vote
0answers
181 views

How can I merge postcode sector polygons into larger territories in QGIS?

I'm new to GIS so patience might be required :-) I'm building a basic web-based mapping tool for business use, to be used as a demo to show that we need one but managers don't know it yet! So far ...
5
votes
5answers
379 views

How to divide a feature class into ranges?

I have a shapefile consisting of around 4000 polygons. The polygons are created from buffering around a similar number of islands somewhere in the Norwegian archipelago. Due to an error in the ...
2
votes
1answer
699 views

How to correctly merge layers with overlapping polygons in QGIS/GRASS?

I have 4 vector shapefile that I would like to join/merge, without worrying about attributes. Here are the shapefiles. I would like to do an union and a spatial dissolve, but everytime I do a dissolve ...
3
votes
1answer
1k views

Use model builder to select layers by attributes, dissolve them and then merge them

StackExchange team, I would like to reclassify polygons, I want to combine smaller polygons into bigger polygons based on their ID (each polygon has a unique ID). I want to regroup ~800 polygons into ...
5
votes
3answers
1k views

Dissolving polygons by attribute and in a certain distance (ArcGIS)

in a FeatureClass I have a lot of polygons which contain attributes of different landuse-types. Now I am trying to dissolve those polygons of the same landuse-type, but only if the distance between ...
3
votes
2answers
150 views

Dissolve column based on attribute in another column

I have 3 columns within a polygon layer I'm working with. Column 1 = Landowner, 3 different values Column 2 = Parcel, N different values Column 3 = Management type, 5 different values I would like ...
5
votes
2answers
197 views

Using newly created features in the next part of a python script

Good Afternoon I am trying to write a python script which buffers a large number of features from a geodatabase (but not all) and then dissolves the newly created buffer shapefiles together. ...
15
votes
4answers
5k views

What is the best way to join lots of small polygons to form a larger polygon?

I have the following layer using SRID 27700 in postgis: It's every administrative region in the UK, and (as you can see from the colour grouping) each of them has a text field specifying the county ...
5
votes
4answers
3k views

Dissolve ploygons in QGIS or Grass to new polygons of defined population sizes

I have a shapefile with 3800 polygons representing the smallest administrative areas in Ireland. Many of these, in rural areas, have tiny populations, under 100 people. In urban areas, all would have ...
3
votes
2answers
1k views

Batch Dissolve Polygons based on Attributes in QGIS or FWTools

I was wondering if anyone can help with batching a dissolve. I have a few hundred polygon shapefiles that I want to dissolve based on an attribute. I would like to do this in QGIS or FWTools. Any ...
2
votes
1answer
149 views

Merge section polygons in PLSS

I am trying to merge quarter quarter sections of polygons from PLSS into a quarter section. However, I also want it assigned to correct Township/Range/Section while merging. I know I can hand merge ...
5
votes
2answers
10k views

How to combine adjacent polygons sharing similar trait into single polygon?

I have a large dataset of habitat classes which I have further simplified down into my own unique classes. However, it resulted in there being habitats adjacent to each other with the same forest ...
5
votes
3answers
3k views

Is there an ArcGIS tool equivalent to “Dissolve” that can be used on tables?

I have a data table that I need to trim down, merging records which have the same value in an ID field and performing a couple math operations on various other fields (summing, averaging). The ...
11
votes
4answers
1k views

ArcGIS - How do I group corner-touching contiguous polygons?

Using ArcGIS 10, I have a Feature Class which I converted from a Raster (GRID) (Raster To Polygon Tool). There are approx. 180,000 polygons. The attribute table contains a [grid_code] field which ...
6
votes
3answers
2k views

Dissolve or unsplit lines on common attributes in PostGIS or GRASS?

I have a road centerline shapefile that has roads split at every intersection. However, I would like to join LINESTRINGs that have a common set of attributes into a single LINESTRING. So long as the ...
3
votes
2answers
2k views

Why is the Dissolve Tool not working?

I'm still having trouble with the dissolve tool and I've tried all of the solutions offered here including moving the process from the background and repairing the geography. I've also tried amending ...
2
votes
1answer
2k views

ArcGIS10 - How do I dissolve two different buffers together so they are not overlapping?

I am trying to find out how many registered sex offenders live within 2,000 feet of a school/park in a specific county. The park buffer and school buffer are dissolved but not together. I am also ...
10
votes
2answers
4k views

How do dissolve polygons from shapefile using open source tools?

In my current project I'm visualizing data on a map representing some values for each administrative areas of a country. I'm given a shapefile of this country, which I'm converting to GeoJSON for use ...
5
votes
2answers
783 views

Practical way of managing polygons and unions of them

I have a table in PostGIS with a quite fine partition of a region, which I'd like to dissolve at two higher levels by means of two foreign keys (e.g. municipality and state). The partition is a real ...
3
votes
0answers
841 views

How to create point labels from midpoints of road polylines in QGIS?

Heres what i want to achieve: i have a roading polyline layer (singlepart ie has several features per road, grouped by an id field), and i want to (after merging the parts) find the mid point of the ...
6
votes
3answers
16k views

How to dissolve overlapping polygons?

I have a query regarding the dissolving of polygon features in ArcGIS 9.3. I only have the bare-bones license and an extremely basic knowledge of VB. I have a large shapefile with around 4500 ...
9
votes
3answers
6k views

Dissolve not working in ArcGIS 10

The dissolve tool is not working for me when I use ArcGIS 10. It works perfectly when I use version 9.3. Any help?
11
votes
3answers
6k views

Is there a dissolve function in PostGIS other than st_union?

I'm looking for a function to dissolve shared boundaries between polygon features in a table. ST_UNION() almost does what I'm looking for, but it creates a multipolygon from all polygons in the layer ...
5
votes
4answers
2k views

How to improve upon ArcGIS Buffer/Dissolve performance?

I'm wondering if anyone else has experienced significant performance penalties when using the ArcGIS buffer function with the 'dissolve' option on point features. My dataset is a shapefile of 260 ...