diff --git a/city_metrix/layers/layer.py b/city_metrix/layers/layer.py index 83fa9eb..cad46bf 100644 --- a/city_metrix/layers/layer.py +++ b/city_metrix/layers/layer.py @@ -135,6 +135,9 @@ def mean(self): def count(self): return self._zonal_stats("count") + def sum(self): + return self._zonal_stats("sum") + def _zonal_stats(self, stats_func): if box(*self.zones.total_bounds).area <= MAX_TILE_SIZE_DEGREES**2: stats = self._zonal_stats_tile(self.zones, [stats_func]) @@ -314,6 +317,8 @@ def _aggregate_stats(df, stats_func): elif stats_func == "mean": # mean must weight by number of pixels used for each tile return (df["mean"] * df["count"]).sum() / df["count"].sum() + elif stats_func == "sum": + return df["sum"].sum() def get_stats_funcs(stats_func): diff --git a/city_metrix/metrics/__init__.py b/city_metrix/metrics/__init__.py index d95cfa5..6efe2ae 100644 --- a/city_metrix/metrics/__init__.py +++ b/city_metrix/metrics/__init__.py @@ -5,3 +5,4 @@ from .urban_open_space import urban_open_space from .natural_areas import natural_areas from .era_5_met_preprocessing import era_5_met_preprocessing +from .recreational_space_per_capita import recreational_space_per_capita diff --git a/city_metrix/metrics/recreational_space_per_capita.py b/city_metrix/metrics/recreational_space_per_capita.py new file mode 100644 index 0000000..2e066d7 --- /dev/null +++ b/city_metrix/metrics/recreational_space_per_capita.py @@ -0,0 +1,16 @@ +from geopandas import GeoDataFrame, GeoSeries + +from city_metrix.layers import WorldPop, OpenStreetMap, OpenStreetMapClass + + +def recreational_space_per_capita(zones: GeoDataFrame, spatial_resolution=100) -> GeoSeries: + world_pop = WorldPop(spatial_resolution=spatial_resolution) + open_space = OpenStreetMap(osm_class=OpenStreetMapClass.OPEN_SPACE) + + # per 1000 people + world_pop_sum = world_pop.groupby(zones).sum() / 1000 + # convert square meter to hectare + open_space_counts = open_space.mask(world_pop).groupby(zones).count() + open_space_area = open_space_counts.fillna(0) * spatial_resolution ** 2 / 10000 + + return open_space_area / world_pop_sum diff --git a/tests/test_metrics.py b/tests/test_metrics.py index 8fd42cc..a68b8ea 100644 --- a/tests/test_metrics.py +++ b/tests/test_metrics.py @@ -44,6 +44,13 @@ def test_natural_areas(): assert expected_zone_size == actual_indicator_size +def test_recreational_space_per_capita(): + indicator = recreational_space_per_capita(ZONES) + expected_zone_size = ZONES.geometry.size + actual_indicator_size = indicator.size + assert expected_zone_size == actual_indicator_size + + def test_urban_open_space(): indicator = urban_open_space(ZONES) expected_zone_size = ZONES.geometry.size