All Questions
65
questions
3
votes
1
answer
247
views
Creating field with difference between areas of two layers in QGIS
In QGIS how can I get the difference between the areas of two layers through field calculator? And is there a way to automatize it so every time a new feature is added the difference updates?
Layer 1 ...
- 1,092
4
votes
5
answers
2k
views
Calculating polygon area in QGIS without adding new field
Is it possible in QGIS to quickly calculate the area of a polygon using a Processing tool, plugin, script without adding attributes or creating a new layer?
Something launching the results window or ...
- 87
2
votes
2
answers
410
views
Calculating how much of polygon is within certain boundary in QGIS
I work for a local authority and I'm measuring the surface area of river catchments inside our local authority.
I have a polygon layer showing me the catchments but a few of them go over our boundary ...
- 21
3
votes
2
answers
360
views
Performing area weighted interpolation in QGIS
I have encountered a problem that I thought would be much more simple than I see it actually is, and conventional clipping did not work.
I have the following grid layer with different values of a ...
4
votes
1
answer
195
views
Calculating area of polygons without script in QGIS Field calculator
Whenever I click the Field Calculator in the attribute table, I am prompted to created a script in order for it to calculate the area of a polygon. However, I do not want to use code in obtaining a ...
- 41
1
vote
0
answers
183
views
Polygon area calculation returning 0.0 QGIS
I am trying to calculate the areas of these 12 individual polygons.
However, when I run the area calculation, two of the polygons return 0.0 - whereas the calculation works for the other 10?
Why is ...
- 199
2
votes
1
answer
361
views
Compare two layers and find the percentage of the shared areas that are different between them
I have two shapefiles that identify flood zones for the same general area but in different years. The maps, however, do not cover exactly the same geographical areas (e.g., shapefile 1 covers counties ...
- 301
3
votes
1
answer
582
views
Finding area of polygons within buffer [duplicate]
I have 102 different sites in two cities, which I have created buffer zones for.
I also have layers that have polygons for different landscape features (e.g. water surface area).
I am trying to find a ...
- 31
1
vote
1
answer
109
views
Adding shapes to polygon feature in the same row
I've got somehow simple issue but cannot process it.
I am working with shapefile in QGIS (3.10 on MacOS), where having several polygon features stored as rows. I want to somehow (manually) edit some ...
- 111
5
votes
2
answers
1k
views
Intersecting area between two polygons in the same shapefile in QGIS
I have a shapefile with two polygons in it. I would like to be able to generate the intersecting area between the two polygons.
Please note, I have tried using the intersect tool, however this does ...
- 241
6
votes
3
answers
482
views
Calculating proportional area of polygon covered by circle [closed]
I have two layers here (ignore the green layer), blue polygons and black circles. I want to calculate for each circle, what percent of the each of the blue polygons does it cover. For example, the ...
- 449
1
vote
1
answer
79
views
QGIS - Inaccurate field calculator
When I retrace a polygon using the measure area tool and get what I believe to be an accurate area measurement. However if I utilise the field calculator within the attribute table to calculate the ...
- 13
1
vote
0
answers
55
views
Grouping of polygons or overlaying layers in same shapefile? Problems calculating the correct polygon areas
I am having trouble calculating polygon areas of my shapefile. When opening the shapefile in QGIS it seems like there are multiple polygons overlapping within the same shapefile or that polygon areas ...
- 61
3
votes
1
answer
1k
views
Calculated area is too large using Field Calculator in QGIS
When I run the Field Calculator to update area, the resulting areas are too large. This happens whether I use QGIS 2.18 or QGIS 3.4.
The default CRS is set to: ESPG:27700, OSGB 1936 / British National ...
- 143
3
votes
3
answers
2k
views
Summing area of polygons within vector layer within zone using QGIS
I have one vector layer with multiple polygons (purple). I also have a number of other vector layers which are catchment zones (I also have a layer where these catchments are merged).
Is there any way ...
- 101