「spatial join」操作

在 Python 中處理地理空間資料

Dani Arribas-Bel

Geographic Data Science Lab (University of Liverpool)

空間關係 I

空間關係 II

哪些城市位於巴西境內？

brazil = countries.loc[22, 'geometry']
cities[cities.within(brazil)]

               name                                       geometry
169        Brasília  POINT (-47.91799814700306 -15.78139437287899)
238  Rio de Janeiro  POINT (-43.22696665284366 -22.92307731561596)
239       São Paulo  POINT (-46.62696583905523 -23.55673372837896)

但如果我們想知道每個城市分別位於哪個國家呢？

Spatial Join

SPATIAL JOIN = 根據空間關係，將一個圖層的屬性帶到另一個圖層

使用 GeoPandas 進行 spatial join

joined = geopandas.sjoin(cities,
                         countries[['name', 'geometry']],
                         op="within")

joined.head()

        name_left                                     geometry name_right
0    Vatican City  POINT (12.45338654497177 41.90328217996012)      Italy
1      San Marino    POINT (12.44177015780014 43.936095834768)      Italy
226          Rome    POINT (12.481312562874 41.89790148509894)      Italy
2           Vaduz  POINT (9.516669472907267 47.13372377429357)    Austria
212        Vienna  POINT (16.36469309674374 48.20196113681686)    Austria

一起來練習吧！

在 Python 中處理地理空間資料