Questions tagged [equal-area]
The equal-area tag has no usage guidance.
18
questions
1
vote
1answer
107 views
Calculate area for Chinese cities
The task is to calculate areas for small project sites (polygons) in various Chinese cities. The dataset is available as EPSG:4490, the project CRS is also set to EPSG:4490. To get accurate comparable ...
0
votes
0answers
31 views
Seeking WMTS service using equal area projection
When looking at campaigning sites, I have been struck that the use of Google maps (because it is easy and works) and therefore the use of epsg:3857 gives undue political impact to certain countries. ...
1
vote
0answers
428 views
Splitting polygon into equal area polygons using shapely
I would like to split complex geometries into n smallest geometries of the same area in Python. While I can divide simple geometry in the following way:
from shapely.geometry import LineString, ...
0
votes
1answer
29 views
Calculating total area of pie charts in ArcMap
Background: I am scaling the size of pie charts by a field which indicates a percentage. I am doing this for two datasets displayed on two maps and would like the resulting areas of the scaled pies to ...
0
votes
0answers
22 views
ArcGIS treats two similar projections definition differently
I am about to recreate a global grid in ArcMAP, based on the Behrmann projection I though.
The map I want to recreate has this definition (in the .prj file):
PROJCS["...
1
vote
0answers
59 views
Calculate total area of both adjacent and contiguous raster cells within a radial distance around a polygon's centroid
I have a raster containing grid-cell values of either 1 or no data, NA, representing used- or unused-habitat types, respectively.
Using R's raster package, I want to calculate the total area (in ...
2
votes
1answer
526 views
Appropriate equal-area cylindrical projection for Southeast Asia?
Background
I am facing difficulty in selecting an appropriate equal-area map projection suitable for the geographical extent of Southeast Asia. The main resource I am consulting is Savric et al's ...
0
votes
1answer
611 views
EPSG codes for projections to use when computing the area of global polygon sets in python env
The general answer to this question is "Use any equal area projection in units of meters that covers the world". Python code needed to make use of this is short and sweet:
import geopandas as gpd
...
4
votes
1answer
517 views
Dividing polygons into equal parts by the number of points inside
I would like to divide many polygons into 2, 3 or 4 parts.
I have vectorized plants. Sometimes 2, 3 or more plants hide under one polygon. Depending on the size I just have to divide the polygon into ...
18
votes
7answers
8k views
Splitting polygon into equal area polygons using QGIS
There is a Plugin in QGIS 2.18 called "Polygon Divider" which divides an irregular polygon into smaller equal-area polygons of a specified/custom-sized but in QGIS 3.x version there is no &...
3
votes
1answer
800 views
Calculate area of ellipsoidal polygon with QGIS
There is online service of GeographicLib, by Karney, where one can calculate the area of ellipsoidal polygon without need of reprojection.
Can one calculate the area of geometry in QGIS so as ...
2
votes
0answers
71 views
Accurate area calculation for countries worldwide individually [closed]
I have polygons of countries with its administrative divisions, I would calculate the areas of each division in a country accurately.
I got the bounding boxes for each country, then I divided its ...
5
votes
2answers
702 views
Geometric difference between equal-area and conformal projection
For simplification, let's have a source light for a map projection.
I know where to put the source light in order to get an orthographic, stereographic, gnomonic map projection, but I still don't ...
3
votes
1answer
181 views
Equal area projection of Antarctica ?
I was looking for an equal area projection of Antarctica, but it seems that the Lambert Azimuthal Equal Area (https://epsg.io/3974 , also called 102020 by ESRI) is deprecated because it is not a "true"...
1
vote
1answer
97 views
How can I use the Eckert IV projection with GeoServer WMS?
I'm trying to request a map in the Eckert IV using a WMS hosted by GeoServer. When I set srs=EPSG:54012 in my query string, I just get a sad XML response:
<?xml version="1.0" encoding="UTF-8" ...
0
votes
0answers
68 views
Equal area projection
In which projection I should project a polygon of a country to get the right area in the attribute table without a distortion? For example greenland
0
votes
1answer
60 views
problem converting OTF from Mercator to equal area
QGIS 1.8.0 on OSX 10.10.5: I've got continent outlines from Natural Earth that are in EPSG:4326 (degrees) plus USGS tree range data in EPSG:2030 (also degrees). When I set the project CRS to EPSG:4326 ...
8
votes
1answer
1k views
Equal area projections with different area results in ArcMap? [closed]
Using ArcGIS, I have to calculate areas of huge polygons all over the Pacific Oceans betwwen 20N and 30S. I have been trying different Equal-areas projections (Cylindrical and sinusoidal for example) ...
