如何从 geoJSON 文件计算多个 MultiPolygons 的面积？

Question

我正在尝试计算 GeoJSON 文件中每个要素（即邻域）的面积。理想情况下，结果将作为字段添加到文件中或单独的数据框中，但我目前甚至无法计算面积。我的代码如下：

import urllib
import json
from area import area

bdry_url = urllib.request.urlopen("https://data.edmonton.ca/resource/xu6q-xcmj.geojson")
with bdry_url as bdry_file:
    bdry = json.load(bdry_file)


for x in bdry['features']:
    print(area(x))

上面代码的结果是很多0。面积函数应该是'calculate the area inside any GeoJSON geometry'。所以，我不确定我是否只是没有将文件正确传递给函数，或者函数是否不像文件中的那样 'MultiPolygons'。

当我在 for 循环中只使用 print(x) 时，输出例如：

{'type': 'Feature', 'geometry': {'type': 'MultiPolygon', 'coordinates': [[[[-113.47970029870794, 53.6152271386194], [-113.47623664663439, 53.61561158319339], [-113.4744820422431, 53.6158162210957], [-113.4731808787134, 53.61590027235317], [-113.4674204545053, 53.61591375444001], [-113.46742798260262, 53.610538856185805], [-113.46743523571406, 53.60691755885339], [-113.46961818955656, 53.60690984975463], [-113.47022601929541, 53.60689581095175], [-113.47086485888067, 53.60685578200864], [-113.4715850828474, 53.606767279197136], [-113.47225008266139, 53.606645830070825], [-113.47373112695321, 53.6063652736457], [-113.47641979230873, 53.6058984811946], [-113.47672620998279, 53.60585027816153], [-113.47791436479508, 53.60576846613057], [-113.48101443948326, 53.605768565180774], [-113.48173969843924, 53.605811862524945], [-113.4824407929969, 53.605915397805376], [-113.48510468465751, 53.606306092276874], [-113.48850157059921, 53.60679389522115], [-113.488933001326, 53.606820031912164], [-113.49168085687263, 53.606784967555676], [-113.49170507787457, 53.60810574183392], [-113.49171395279058, 53.61275181411882], [-113.49179330220164, 53.614032553715944], [-113.48966991380574, 53.6140237367952], [-113.48906656552556, 53.61404155038072], [-113.48794288078807, 53.614190044322235], [-113.48600883911077, 53.61444001996334], [-113.47970029870794, 53.6152271386194]]]]}, 'properties': {'descriptio': 'Evansdale is named for H.M.E. Evans, Mayor of Edmonton in 1918. Mr. Evans was also president of the Edmonton Board of Trade in 1916. Although single detached homes account for 90% of the structures in Evansdale, almost 50% of the dwelling units are locat', 'descriptiv': 'Evansdale', 'name': 'EVANSDALE', 'neighbourh': '2260'}}

Answer 1

看起来 area 库 只需要 几何图形，而不是整个特征。所以试试这个：

for x in bdry['features']:
    print(area(x['geometry']))

如何从 geoJSON 文件计算多个 MultiPolygons 的面积？

How to calculate the area of several MultiPolygons from a geoJSON file?

python

geojson

python-3.x