To merge features based on specified attributes.

learn more… | top users | synonyms

1
vote
0answers
28 views

PostGis - st_union polygons, keep sum of attribute

There are multiple My current query is: SELECT (ST_Dump( ST_Union( way ) )).geom AS way, 10000 AS way_pixels FROM ( SELECT way, way_pixels, ...
1
vote
1answer
195 views

How to dissolve by two fields?

I have a shapefile with many polygons in it. I want to dissolve by two fields. Is there any possible way to dissolve this by NAMA_KPH and PL15_ID?
3
votes
1answer
110 views

Converting Road Lines to a Binary Raster Image

I got road data from the USGS database and imported it into QGIS. And I want to transform it into a binary raster image that looks like this in QGIS (this is only a processed screen shot but I want ...
1
vote
3answers
37 views

ArcGIS Dissolve/SQL group by

I have a GIS layer that has thousands of Facility IDs. For each Facility ID there can be multiple Chemical ID's. For each chemical ID there is a maximum of 3 zone types. Zone A, B, C. But there is not ...
1
vote
1answer
30 views

ArcGIS 10.3 Dissolve tool splitting up lines, not dissolving them

I have noticed strange behaviour with the Dissolve tool so tried a test on three line segments, snapped to the same central point. The line segments each consist of exactly two vertices i.e. the end ...
1
vote
0answers
46 views

SAGA Gis and QGIS: difficulties in dissolving polygons

I am new in using GIS and I'm having some problems in properly dissolving some polygons. In particular, I have a single layer with about 3,000 polygons (protected areas), some of which overlap (the ...
3
votes
1answer
35 views

Assigning common field value to segments between two points using ArcGIS for Desktop?

I am using ArcGIS 10.3 for Desktop. I have a shapefile with polylines connecting points. Instead of having one single polyline connecting two points, there exist a number of consecutive segments ...
0
votes
1answer
22 views

Traces outside polygons after merging several polygons together

I'm using ArcMap 10.3.1 I have a polygon shape file for areas upstream of 5 monitoring sites. I used dissolveand merge to merge all these polygons together. You can download the resulting shape file ...
2
votes
0answers
11 views

How to create one attribute containing multiple adjacent parcels?

I'm trying to upload town parcel data to my Garmin GPS from Esri. Garmin registers each attribute as an entirely different file, and requires you to 'turn on' each file to display it on the GPS. This ...
2
votes
4answers
103 views

merge overlapping polygons with spatialite

The green points, buffered by one of the point attributes, should result in the three areas outlined in red (a table with three rows): I'd like to do it in spatialite. How can I do that? If it's ...
3
votes
0answers
35 views

QGIS Dissolve skips polygons

I'm having trouble with the dissolve function in QGIS. Is it because of an overlap? It's not a GRASS layer, just shapefiles. I'm new with GIS software in general. Searched for similar problems but ...
2
votes
0answers
24 views

Unsplit line Reversing Line Direction [closed]

I am using the unsplit line tool and I noticed that the direction of the lines with multiple segments is getting switched the opposite direction while the single sections seem to continue in the ...
1
vote
0answers
41 views

ArcPy Dissolve Statistics Fields - fixed into variable

How can I change this fixed POP column into my variable: field = parameters[1].valueAsText. It says syntax error everytime. StatField = "POP MIN;POP MAX" arcpy.Dissolve_management(in_features, ...
3
votes
0answers
116 views

Dissolve Management in Python

I have a simple code that is pulling together polygon shapefiles from a Windows folder and merging them together into a single shapefile. In the same code, I want to add a dissolve command. My fields ...
1
vote
1answer
94 views

Merge and dissolve overlapping polygons?

I have a situation in which I have both network buffers and circular buffers around the same points (as separate feature classes), and I want to merge the buffers and dissolve into one polygon for ...
1
vote
1answer
42 views

Arcgis dissolve output has greater area than inputs

I've been using dissolve to successfully merge polygons (which may or may not overlap) representing mining tenements so that I can calculate their total coverage area (using the geodesic area ...
4
votes
4answers
131 views

QGIS classifying vector data

I am trying to classify a shapefile based on rule set, following this tutorial. This is the result: What I want to ask is: 1. How to insert the classification result (water, land etc) into the ...
1
vote
3answers
32 views

Dissolving while retaining field informations in the same entry instead of multiple entries

I have 1520 covenants. Many covenants have more than 1 VM symbols attached to it, currently showing as rows. EG. Covenant #97 has 4 VM Symbols, with the VM Symbols 1, 67, 117 and 171. How do I change ...
5
votes
1answer
100 views

Dissolve overlapping polygons according to percent overlap using PostGIS?

I have a shapefile with convex hull polygons, all in the same layer/shapefile. Some of the polygons overlap (not duplicate polygons). I would like to dissolve/union the polygons which overlap with ...
1
vote
0answers
45 views

Merging multiple fields with same parcel id yet different attribute values, while keeping all fields?

I am using ArcGIS 10.3 for Desktop. I have a property parcel layer that when Intersected, each parcel is broken up into hectares of different land covers. My question is can this be merged (or ...
1
vote
1answer
59 views

How to dissolve polygons that overlap both on each other in QGIS?

I have two layers of polygons with landcover classes(meadows, cropland, forest, ect) They overlap in both directions, i.e like a zipper. I need to dissolve them by one attribute (Class) so I can have ...
3
votes
3answers
60 views

Dissolving redundant fields in ArcGIS for Desktop?

I have a map of a small neighbourhood. I'm trying to label these but because of the grid being squares the objects are split and therefore showing two two or more labels of each location. I'm trying ...
2
votes
0answers
53 views

Combining adjacent shapefiles and merging neighbor polygons currently divided by quad boundaries

The project I'm working on has been mapping ecological sites in ArcGIS on a quad-by-quad basis for the past 10 years. When entered into GIS, each quad has its own shapefile and the sites are cut off ...
3
votes
2answers
188 views

Dissolve a polyline feature class so that touching features dissolve into a single feature

I'm trying to dissolve a polyline feature class so that spatially intersecting features become a single feature. When I run the Dissolve tool, setting Create multipart features and Unsplit lines both ...
2
votes
2answers
177 views

Dissolve line segments in QGIS if they touch and fall within the same class. (tools or script?)

I have line segments that have the following 3 attributes (Class, start_point, end_point). I would like to merge/dissolve line segments that fall within the same class if they intersect (touch). i.e. ...
5
votes
3answers
125 views

Dissolve overlapping polygons in SAGA

I've got the following (2D!) situation of overlapping polygons: I would like to have the polygon border dissolved such that I have only one polygon left. I thought this was a definitive case for ...
1
vote
1answer
83 views

Dissolving in ArcMap gives “Invalid Topology [Duplicate Segment.]”

I am attempting to use the dissolve tool on a shapefile, but it fails with the error: ERROR 999999: Error executing function. Invalid Topology [Duplicate segment.] I tried checking and repairing ...
3
votes
2answers
115 views

Dissolving with PostGIS slow and results in large table?

I am having a table of polygons with some 15 Mio. records. The polygons hold an attribute called "dn" with integer values between 0 and 6. My goal is to simplify that table so that polygons below a ...
1
vote
1answer
65 views

Invalid parameters using ArcPy dissolve and statistics_fields

I am trying to use the Dissolve_management tool using ArcPy. I keep getting an error that reads "Parameters are not valid.", and I cannot figure out where I am going wrong. Here is the code: env....
1
vote
2answers
72 views

Dissolving contiguous clusters of polygons and identifying them separately in attribute table of ArcGIS for Desktop?

I have a layer comprised of about 500,000+ simplified polygons that resulted from converting raster cells to polygons with raster cell values assigned to them. When I select the resultant polygons by ...
0
votes
0answers
98 views

Dissolve in python script not working correctly

I have a python script that merges 12 shapefiles into 1 shapefile with about 75k total records. I want to dissolve the latter shapefile on a particular field, and SUM another field, so my final ...
0
votes
0answers
47 views

Mulitpart dissolve equivalent with SQL Server

SQL Server 2012 has introduced a handy set of geographic aggregate functions that is well summarized here. Among the aggregate functions are UnionAggregate and CollectionAggregate. UnionAggregate is ...
3
votes
0answers
121 views

Dissolving polygons in a large dataset

I need to dissolve polygons by the ID attribute in a large dataset (+-1gb shapefile). I have been struggling to find an efficient method to do this. I have tried the following methods: Postgis ...
1
vote
1answer
77 views

QGIS 2.12 Lyon - SAGA dissolve tool keep only one column of data

I have installed QGIS 2.12 Lyon and I need to dissolve multiple polygons according to one column in the dbf file (my layer is a shape file). I have used SAGA "Polygon dissolve by attribute" algorithm ...
2
votes
1answer
127 views

PostGIS: How to dissolve vector data

I have a few scenarios where I need to dissolve vector data, and I'm wondering how to do this using PostGIS. What would the queries look like to perform these operations? Below I'll describe the ...
0
votes
0answers
18 views

Dissolving and labeling time enabled data using ArcGIS Online?

I have 12 feature classes with time-enabled data (~4000 polygons each), where each polygon corresponds to an administrative unit between certain years. So a polygon can appear several times or only ...
0
votes
0answers
366 views

Dissolve using GDAL/OGR?

I'm trying to dissolve a shapefile according to a field using Python 2.7.10 and I don't want to use ArcPy. Is there any way to do this using GDAL/OGR?
1
vote
2answers
471 views

Dissolve multiple polygons into one based on background layer

I have a layer of regions (25 regions) and a layer with thousands of polygons. I want to dissolve this into 1 polygon for each region (so I can calculate the exact geometry). I used the dissolve tool ...
1
vote
2answers
137 views

Overlapping polygons and features and how to dissolve

I am new to GIS area and also new to any software that can modify the GIS. I am currently working with South Australia map I have download from Australian census site. I am using QGIS to load the ...
2
votes
1answer
46 views

Dissolving Features from different Layers

I'm trying to dissolve polygon features from different layers by their FID. If two polygons have the same FID the result should be one single polygon. Maybe this drawing will help to make clear what I'...
6
votes
1answer
225 views

Deleting 'garbage' nodes after polygon dissolve

I work with QGIS 2.10.1 on Windows 7 (x64). I have dissolved polygons from an attribute value and the polygons geometries being not perfectly joined together, I get some 'garbage' nodes I need to ...
7
votes
1answer
1k views

Dissolving shapefile but retain attribute fields

Is there any way to dissolve shapefile but keep attributes fields in the same time? This is how I want to retain fields: There are two fields I want to conserve in a shapefile. The first column is ...
2
votes
1answer
74 views

Dissolving a TIN using python/ogr binding

I have a TIN model where I remove some of the triangles (see fig. 1). Most of the triangles touch on one edge, some on one vertice. I would now like to generate a polygon shapefile containing the ...
0
votes
1answer
42 views

Identify polygons greater than n-th percentile and perform further analyses using arcpy

My goal is to identify tracts that are above the 99 percentile of a variable (xvar), to dissolve contiguous tracts by summing a variable (yvar), and to get the coordinates of the centroids (...
0
votes
2answers
80 views

How to Dissolve Polygons Inside a Feature Class Based on Attribute Conditions

I have a large shapefile (saleArea.shp) which includes hundreds of small adjacent polygons. I would like to dissolve the polygons based on some conditions from tValues field into 5 bigger groups like ...
1
vote
1answer
139 views

Dissolve overlapping polygons in R

Is there an analogue of ArcGIS Dissolve function in R? I need to dissolve the overlapping polygons and create a single part object. I was trying to use gUnionCascaded, but it creates a multipart ...
5
votes
2answers
92 views

Identifying a cluster of polygons based on attributes

I'm trying to identify a cluster of contiguous parcels that, when combined, add up to at least a given size and, when combined, have an assessed property value less than a given $ amount. I have a ...
0
votes
0answers
112 views

How to dissolve a large number of polygons in QGIS?

I'm trying to do it using the command DISSOLVE but it generates an empty shapefile. My purpose is to dissolve a large number of polygons (about 200,000) into a single multi-polygon...
1
vote
0answers
74 views

Make “qgis:delaunaytriangulation” and “qgis:dissolve” save their outputs on a specific predefined layer

I'm new to python and QGIS. I'm working on modifying a plugin which runs algorithms "qgis:delaunaytriangulation" and "qgis:dissolve" like so delone_triangles = processing.runalg("qgis:...
2
votes
3answers
96 views

Dissolve without removing interior lines in ArcMap? [duplicate]

I'm fairly new to GIS and I'm having an issue that I hope someone can help me resolve? Basically, what I'm trying to do is merge features based on a single attribute so that my table no longer ...