get the area in square meters of a polygon using shapely and pyproj

projected_area.py

import pyproj
from shapely.geometry import shape
from shapely.ops import transform

geom = {'type': 'Polygon',
        'coordinates': [[[-122., 37.], [-125., 37.],
	                     [-125., 38.], [-122., 38.],
                         [-122., 37.]]]}

s = shape(geom)
proj = partial(pyproj.transform, pyproj.Proj(init='epsg:4326'),
               pyproj.Proj(init='epsg:3857'))

s_new = transform(proj, s)

projected_area = transform(proj, s).area

See also: https://stackoverflow.com/q/51554602/562769

from functools import partial

thnks!

Thanks for sharing this

Thank you.

Please note that init='epsg:4326' is deprecated. use 'epsg:4326' instead.

Hello,
when I am trying to calculate the area with the code above without init='epsg:4326' some values are returned as nan, while with it I have an output. Does anyone experience the same kind of problem?

Hello,
when I am trying to calculate the area with the code above without init='epsg:4326' some values are returned as nan, while with it I have an output. Does anyone experience the same kind of problem?

same here :-O

import pyproj
from shapely.geometry import shape
from shapely.ops import transform

geom = {'type': 'Polygon',
'coordinates': [[[-122., 37.], [-125., 37.],
[-125., 38.], [-122., 38.],
[-122., 37.]]]}

s = shape(geom)
wgs84 = pyproj.CRS('EPSG:4326')
utm = pyproj.CRS('EPSG:3857')
project = pyproj.Transformer.from_crs(wgs84, utm, always_xy=True).transform
projected_area = transform(project, s).area
print(projected_area )

This worked for me.

How would one use this code to interate over a gdf that contains the polygons in a column?

import pyproj from shapely.geometry import shape from shapely.ops import transform

geom = {'type': 'Polygon', 'coordinates': [[[-122., 37.], [-125., 37.], [-125., 38.], [-122., 38.], [-122., 37.]]]}

s = shape(geom) wgs84 = pyproj.CRS('EPSG:4326') utm = pyproj.CRS('EPSG:3857') project = pyproj.Transformer.from_crs(wgs84, utm, always_xy=True).transform projected_area = transform(project, s).area print(projected_area )

This worked for me.

I think worked for me too!