Measure of quantity of a two-dimensional surface
2
votes
1answer
46 views
How does QGIS calculate the area of a polygon?
I am working on a project that requires the calculation of the area of a polygon by two different methods. I need to know what algorithm QGIS uses to calculate the area of a polygon. I know ESRI ...
1
vote
1answer
46 views
Calculating area
I have a polygon layer.
I toggled to edit mode.
I added a new column, while number (integer) and called it "area".
I then use the field calculator - geometry - $area to populate the polygon area for ...
1
vote
1answer
338 views
Calculate polygon area inside extent
We're using ArcMap 10.0 sp5, creating a tool in c# using the ArcObjects sdk.
Is there a built in function or simple set of steps that calculates the area of each feature of a polygon layer within a ...
5
votes
0answers
596 views
How to split polygons without ArcView?
I'm trying to split polygons into equal areas. While fishnet sort of works; the areas I'm trying to split don't touch; they're national parks. Fishnet spans the whole area, not just the polygons in ...
3
votes
0answers
159 views
Polygonize vegetation area from Landsat7 RGB using QGis / Bilko?
I'm trying to extract the areas with vegetation as a polygon-shape from a landsat7-image, 30m resolution, RGB, using QGis 1.8 or Bilko or (hopefully in the near future) ArcGIS. The area is in Northern ...
2
votes
0answers
62 views
Raster area (QGIS) problem explained
I would like to know the area that each value in a raster has... The raster I have has values from 2-15 and I would like to know the area that each value is occupaying within my polygon... Thanks!
I ...
2
votes
0answers
67 views
GeoTools, add column in query with CQL
I'm trying to query the database (DataStore) and want to let the datastore calculate a value for me.
In SQL I would do it like this:
SELECT name, ST_Area(ST_Intersection(the_geom, ....) AS myValue ...
2
votes
0answers
436 views
How to calculate the area of a polygon considering the relief?
I work in a fire department and i'm mapping all the fires that occur in my area, creating polygons that represent burnt areas.
my problem is that the values are not accurate... for instance, arcgis ...
1
vote
0answers
57 views
How calculate areas between certain contour lines in qgis?
Sorry for asking a question which I found in similar ways already here, but I am trying this for days and just got no result:
How do I calculate the area between certain contour lines (e.g. 0-800, ...
0
votes
0answers
74 views
SqlGeography STArea for CW and CCW polygons
I'm using a SqlGeographyBuilder to make a simple polygon (with SRID of WGS84). When I add the vertices CW and call the STArea() method, The area would be very large. When I add the vertices CCW and ...
