All Questions
65
questions
1
vote
1
answer
1k
views
Processing area and calculating volume of polygon with know elevation from DEM in QGIS
I got a DEM of a watershed and I need to create a dam at a fixed elevation (with a rectangular polygon corresponding at the top of the dam) and calculate it's area (including the slope (fixed value) ...
- 49
2
votes
0
answers
598
views
Calculating the area of raster within polygon
I have a raster layer with values of energy demand in each cell. I would like to know the area of the raster within each polygon (see screenshot). Any suggestions on a simple approach for this?
- 181
0
votes
1
answer
1k
views
Calculating area under each polygon in QGIS [duplicate]
I would like to know how to calculate the area of the vector layer (red in the photo) under each polygon (white square in the photo). The red layer has the area (km2) in its attributes. But what I ...
- 21
2
votes
3
answers
5k
views
Calculating polygon area within polygons in QGIS
I want to estimate the area of the reef under a polygon grid.
My shapefiles are already in meters, however I am having a hard time calculating the area under the grid layer. Attached are the photos.
I ...
- 21
1
vote
1
answer
345
views
Area difference between polygon layers
I would like to calculate the difference of area between two polygons. I tried using the Difference tool, but all it does is create lines that are different between my two polygons. I also tried the ...
- 63
2
votes
1
answer
769
views
Selecting polygons which contain majority of area from intersected layer by polygons using QGIS?
I have two polygons layers (a squares grid (blue in image) and a rectangles grid (green in image)). Because the different polygon sizes, different squares overlap with a single rectangle. I need to ...
- 23
2
votes
2
answers
2k
views
Area of Intersection between two polygon files in QGIS
I'm new to mapping concepts and software.
I need to report on the intersecting area of postcode polygons and NBN Rollout areas. So postcode 3000 has 3 units of area in rollout region 1 and 6 units of ...
- 21
4
votes
1
answer
972
views
Why the outcome of $area (geometry), is different from area saga shape indices tool in QGIS?
I am puzzled on why I get different outcomes on trying to calculate the area (m2) for multiple polygons in QGIS.
My polygons consist of tiny objects of few cm extent.
When using $area (field ...
2
votes
2
answers
5k
views
Polygon in specific size
I have the task of inserting a polygon in a map with a specific size. My idea is to simply "draw" a polygon and keep on enhacing its size, until it reaches the size I actually want to be. Its ...
- 557
2
votes
1
answer
241
views
QGIS Aggregate function missing
I want to sum the areas of several polygons in the same shape layer by using the Aggregate function in Select features using an expression. However, I can't find the Aggregate menu nor the SUM ...
- 33
0
votes
1
answer
3k
views
Getting area of polygons in QGIS [duplicate]
I have a world map divided into zones and need to compute the area for each polygon. I tried using Vector > Geometry Tools > Export/Add geometry columns and successfully get the area and perimeter but ...
- 69
1
vote
1
answer
62
views
Calculate areas of each soilscape type per boundary
I would like to do the following:
Get the area of each soilscape type
Calculate the sum of area per boundary
I'm trying to do the following but seems the output is always "0"
- 13
6
votes
1
answer
288
views
Calculating Statistics Based on Expression in QGIS?
Is it possible to calculate the sum of polygon areas based on whether or not it has a value in another column?
For example:
In column 2 I have the area of polygons. I want to calculate the area of ...
- 385
2
votes
1
answer
4k
views
Calculating polygon area inside another polygon in QGIS
Is it possible to calculate the area of colorful polygons (yellow, yellowish/reddish and red) inside another shapefile (purple outline, also polygons) in QGIS.
For example the polygon that is marked ...
- 91
4
votes
2
answers
8k
views
Displaying unit as 'text' within label in QGIS?
When labelling areas in QGIS I can't figure out how to display the unit after the number value from a field.
For example the area of my polygon might be 1.23 hectares, which has been calculated ...
- 41