0
votes
1answer
54 views

QgsGeometryAnalyzer.dissolve problems

I am completely new to the QGIS python api and I am running into an error which I cannot solve when trying to use the dissolve class. I used the basics of the PyQGIS Cookbook. In my understanding ...
1
vote
1answer
133 views

Dissolve large dataset in ArcGIS and QGIS

I have more than 80k point data. I have created few buffer from 1 to 5 km of them. Now I want to get the covered area by 1 km to 5 km buffered range. For this I have tried to dissolve those individual ...
0
votes
0answers
42 views

How to get the boundaries of a polygon by property

I have the cartography of my city (Santiago) and i need to obtain the nodes that conform the hull (not necessarily convex) of different districts, the boundaries. Each node has the same "DIS"( ...
1
vote
0answers
25 views

How do I dissolve to a predetermined number of contiguous geographies based on equal division of a value?

Let's say I have a layer that is the state of Oklahoma, broken up by county, and I want to dissolve it into contiguous regions of roughly equal population size, and I want to define how many regions ...
0
votes
1answer
61 views

Dissolving polygons closers than 50m into a single shape QGIS

I’m new with GIS (coming from a CAD background) and using QGIS 2.0.1. I have a very detailed map of urban fabric in a UK region, to the detail of individual buildings. I want to simplify that map by ...
1
vote
2answers
2k views

How to Merge/Dissolve Polygons By Common Attribute Field in QGIS?

I have joined corresponding Local Enterprise Partnerships table data into a polygon shape file containing UK Local Authorities. How do I Dissolve or Merge the the Local Authorities polygons by ...
0
votes
0answers
48 views

Dissolving overlapping polygons - issue in QGIS [duplicate]

I have the OS Code-Point map which I want to dissolve into the regions that my company use. I have used the dissolve function in QGIS, but it is having a problem where a vertical street overlaps with ...
4
votes
2answers
1k views

Dissolve polygons in QGIS (GEOS) with tolerance

I have a polygon vector layer representing the area inundated in a flood. The layer has been produced in a such a way that some of the areas are composed of multiple smaller touching polygons (see ...
0
votes
1answer
110 views

Why does the “Dissolve” tool in QGIS create an empty layer?

I have a shapefile containing cadastral data. I would like to dissolve the polygons using my field "OwnerName". My goal is to get one polygon per landlord's name. When I use the "Dissolve" tool, QGIS ...
0
votes
0answers
38 views

Dissolving a vectorial shape/layer in QGis with raster layers and after that cut the raster layers based in an vectorial one ( South America)

I'm doing a work for colege about the potential distribution of an species that exists only in South America using QGis 1.7.4 Wroclaw but I need to use the raster layers (from www.worldclim.org) of ...
4
votes
1answer
692 views

What dissolve tool in QGIS allows me to summarize statistics for multiple attributes?

Is there a tool or plugin in QGIS that resembles ArcGIS 10's Dissolve tool? I'm trying to dissolve several polygons (parks) around the boundaries of another layer of polygons (cities), while ...
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 ...
4
votes
1answer
122 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. ...
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 ...
3
votes
0answers
162 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 ...
3
votes
1answer
269 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 ...
1
vote
0answers
179 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 ...
2
votes
1answer
679 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 ...
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 ...
3
votes
0answers
824 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 ...