All Questions
14
questions
123
votes
8
answers
354k
views
Calculating polygon areas in shapefile using QGIS
How do I calculate areas of an area shapefile in square meters (m²) or in acres (ha)?
I didn't find that functionality in the Vector Tools.
- 2,321
14
votes
2
answers
57k
views
Calculating polygon areas and perimeters using QGIS
Using QGIS, if I load a polygon layer and make a new column, how do I fill that column with the area of each polygon and another column with the length of the perimeter of each polygon?
- 995
10
votes
2
answers
9k
views
Calculating proportional area of polygon within another layer's polygon using QGIS
I have two polygon layers, 'model' and 'ntem', whose features overlap and intersect one another.
I would like to calculate the proportion of the area of the 'model' polygons which fit within each '...
- 497
6
votes
2
answers
2k
views
Wrong $area from field calculator (QGIS)
The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
- 283
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
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
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
10
votes
2
answers
2k
views
Defining hexagon area around mapped points using QGIS
I am using QGIS to map a number of radio antennas (for mobile network).
Once I have the layer of the sites (done), I would like to assign to each site a coverage area (envelope). I could achieve that ...
- 101
4
votes
1
answer
2k
views
Selecting polygon with the largest area in QGIS
I would like to select the largest number in a column of an attribute table by "Select by attributes" in QGIS to select the polygon with the largest area. How would be the expression for ...
- 181
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 ...
3
votes
1
answer
2k
views
How can I get my Qgis area calculations in metres rather than degrees? My shapefiles are projected using WGS 1984 UTM fuseau 35 Sud
I am using Qgis 1.7.4 to calculate the area of polygons. My shapefiles have been projected using the coordinate system WGS 1984 UTM fuseau 35 Sud, but my area calculations are still displayed in ...
- 31
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
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
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