GeoPandas Shapely – Understanding Units in GeoPandas GeoSeries Area Function

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I have a GeoPandas DataFrame. I apply a couple of functions to the GeoDataFrame.

  1. Buffer – https://geopandas.org/en/stable/docs/reference/api/geopandas.GeoSeries.buffer.html

This creates a set of points around the coordinates / geometry.

import geopandas
from shapely.geometry import Point, LineString, Polygon

    s = geopandas.GeoSeries(
        [
            Polygon([(0, 0), (1, 1), (0, 1)]),
            Polygon([(10, 0), (10, 5), (0, 0)]),
            Polygon([(0, 0), (2, 2), (2, 0)]),
            LineString([(0, 0), (1, 1), (0, 1)]),
            Point(0, 1)
        ]
    )

    s.buffer(0.2)

  1. Now, I'd like to measure the area of the buffered geometry using: https://geopandas.org/en/stable/docs/reference/api/geopandas.GeoSeries.area.html

    s.area

The crs info of the DataFrame is:

<Derived Projected CRS: ESRI:102003>
Name: USA_Contiguous_Albers_Equal_Area_Conic
Axis Info [cartesian]:
- E[east]: Easting (metre)
- N[north]: Northing (metre)
Area of Use:
- name: United States (USA) - CONUS onshore - Alabama; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming.
- bounds: (-124.79, 24.41, -66.91, 49.38)
Coordinate Operation:
- name: USA_Contiguous_Albers_Equal_Area_Conic
- method: Albers Equal Area
Datum: North American Datum 1983
- Ellipsoid: GRS 1980
- Prime Meridian: Greenwich

What is the units of the area calculated?

Best Answer

According to it's Well Known Text (WKT) definition is meters

PROJCS["USA_Contiguous_Albers_Equal_Area_Conic",
    GEOGCS["GCS_North_American_1983",
        DATUM["North_American_Datum_1983",
            SPHEROID["GRS_1980",6378137,298.257222101]],
        PRIMEM["Greenwich",0],
        UNIT["Degree",0.017453292519943295]],
    PROJECTION["Albers_Conic_Equal_Area"],
    PARAMETER["False_Easting",0],
    PARAMETER["False_Northing",0],
    PARAMETER["longitude_of_center",-96],
    PARAMETER["Standard_Parallel_1",29.5],
    PARAMETER["Standard_Parallel_2",45.5],
    PARAMETER["latitude_of_center",37.5],
    UNIT["Meter",1],
    AUTHORITY["EPSG","102003"]]

https://epsg.io/102003

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