如何从 BigQuery 中的 Openstreet 地图数据集中提取所有国家/地区的几何图形

Question

我正在使用这个查询来使用 OSM 提取所有国家/地区的几何图形，它工作正常，但我敢肯定，它正在创建一个副本，因为我使用标志作为参考，有些地方有一个标志，但是他们不是真正的国家

SELECT feature_type, osm_id, osm_timestamp, geometry,ar.key,ar.value,
  FROM `bigquery-public-data.geo_openstreetmap.planet_features`,UNNEST(all_tags) ar
   where ('boundary', 'administrative') IN (SELECT (key, value) FROM UNNEST(all_tags))
   and(feature_type="polygon" or feature_type= "multipolygon")
   AND ('flag') IN (SELECT (key) FROM UNNEST(all_tags)) and ar.key="name" order by st_area(geometry) desc

抱歉忘了说，有些标签丢失了，例如，如果你 select admin_level = 2，像美国这样的国家会被删除

Answer 1

根据https://wiki.openstreetmap.org/wiki/Tag:boundary%3Dadministrative#National admin_level = 2 描述国家。

所以我整理了您的查询并添加了 admin_level = 2 个过滤器，以便它只包含国家/地区。

SELECT 
  feature_type, osm_id, osm_timestamp, geometry,
  (SELECT value FROM UNNEST(all_tags) WHERE key = 'flag') as flag,
  (SELECT value FROM UNNEST(all_tags) WHERE key = 'name') as name,
  st_area(geometry) as area
FROM `bigquery-public-data.geo_openstreetmap.planet_features`
WHERE 
  feature_type in ("polygon", "multipolygon")
  AND EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'boundary' AND value = 'administrative')
  AND EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'flag') 
  AND EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'admin_level' AND value = '2') 
ORDER BY area desc

对于美国，我发现 link 解释了关于美国的一切.. https://wiki.openstreetmap.org/wiki/United_States/Boundaries#National_boundary

您可以在此处查看美国的 openstreetmap 记录 https://www.openstreetmap.org/relation/148838#map=1/41/0 在左侧，有所有功能。

此外，您可以通过以下方式在 BigQuery 中查找美国记录：

SELECT *
FROM `bigquery-public-data.geo_openstreetmap.planet_features`
where osm_id = '148838'

即使在 openstreetmap 记录中有 admin_level，它在 BigQuery 记录中也不存在。不知道为什么，可能是旧版本吧

因此您可以使用上面的查询优化您的过滤器以包括美国。

Answer 2

我们可以通过合并 2 个表来列出所有国家及其几何形状：

SELECT features.feature_type, features.osm_id
  , ARRAY(
     SELECT DISTINCT AS STRUCT * FROM UNNEST(features.all_tags||relations.all_tags)
     WHERE key IN('int_name', 'name')
     ORDER BY 1 LIMIT 1 
  ) features
 , ROUND(ST_AREA(geometry)/1e6,1) area
FROM
  `bigquery-public-data.geo_openstreetmap.planet_features` AS features,
  `bigquery-public-data.geo_openstreetmap.planet_relations` AS relations
WHERE ('boundary','administrative') IN (SELECT (key,value) FROM UNNEST(features.all_tags))
AND ('admin_level','2') IN (SELECT (key,value) FROM UNNEST(relations.all_tags))
AND feature_type = 'multipolygon'
AND relations.id=SAFE_CAST(features.osm_id AS INT64)
ORDER BY area

(ref)

Answer 3

受前面两个不再有效的答案的启发。由于 GeoOpenStreet 中的一些枚举类型更改（例如将多边形重命名为多边形），并且不认为该标志是强制性的，而是 ISO 代码。

SELECT (SELECT value FROM UNNEST(all_tags) WHERE key = 'ISO3166-1:alpha2') as CountryISO2Code,
  geometry AS CountryGeometry,
  st_area(geometry) as CountryArea
FROM `bigquery-public-data.geo_openstreetmap.planet_features`
WHERE EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'boundary' AND value = 'administrative')
  AND EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'admin_level' AND value = '2') 
  AND EXISTS (SELECT 1 FROM UNNEST(all_tags) WHERE key = 'ISO3166-1:alpha2') 
ORDER BY CountryArea DESC

如何从 BigQuery 中的 Openstreet 地图数据集中提取所有国家/地区的几何图形

how to extract all countries geometry from Openstreet map dataset in BigQuery

gis

openstreetmap

google-bigquery