More nuanced waterway

layers/waterway/README.md

@@ -6,6 +6,7 @@ Too short linestrings are filtered out for some zoom levels. Waterways do no not
 
 ## Fields
 
+- **name**: The OSM [`name`](http://wiki.openstreetmap.org/wiki/Key:name) value of the waterway or the name from Natural Earth for lower zoom levels.
 - **class**: The original value of the [`waterway`](http://wiki.openstreetmap.org/wiki/Key:waterway) tag.
 Can be one of [`stream`](http://wiki.openstreetmap.org/wiki/Tag:waterway%3Dstream),
 [`river`](http://wiki.openstreetmap.org/wiki/Tag:waterway%3Driver),

layers/waterway/mapping.yaml

@@ -1,14 +1,19 @@
 generalized_tables:
-  # etldoc: imposm3 -> osm_waterway_linestring_gen0 
+  # etldoc: imposm3 -> osm_waterway_linestring_gen3
-  waterway_linestring_gen0:
+  waterway_linestring_gen3:
-    source: waterway_linestring_gen1
+    source: waterway_linestring_gen2
-    sql_filter: waterway IN ('river') AND ST_Length(geometry) > 10000
+    sql_filter: waterway IN ('river')
     tolerance: 200.0
-  # etldoc: imposm3 -> osm_waterway_linestring_gen1    
+  # etldoc: imposm3 -> osm_waterway_linestring_gen2
+  waterway_linestring_gen2:
+    source: waterway_linestring_gen1
+    sql_filter: waterway IN ('river')
+    tolerance: 100.0
+  # etldoc: imposm3 -> osm_waterway_linestring_gen1
   waterway_linestring_gen1:
     source: waterway_linestring
-    sql_filter: waterway IN ('river') AND ST_Length(geometry) > 5000
+    sql_filter: waterway IN ('river')
-    tolerance: 100.0
+    tolerance: 50.0
 tables:
   # etldoc: imposm3 -> osm_waterway_linestring
   waterway_linestring:

layers/waterway/merge_waterway.sql

@@ -0,0 +1,44 @@
+-- We merge the waterways by name like the highways
+-- This helps to drop not important rivers (since they do not have a name)
+-- and also makes it possible to filter out too short rivers
+
+-- etldoc: osm_waterway_linestring ->  osm_important_waterway_linestring
+CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring AS (
+    SELECT
+        (ST_Dump(geometry)).geom AS geometry,
+        name
+    FROM (
+        SELECT
+            ST_LineMerge(ST_Union(geometry)) AS geometry,
+            name
+        FROM osm_waterway_linestring
+        WHERE name <> '' AND waterway = 'river'
+        GROUP BY name
+    ) AS waterway_union
+);
+
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_geometry_idx ON osm_important_waterway_linestring USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring -> osm_important_waterway_linestring_gen1
+CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring_gen1 AS (
+    SELECT ST_Simplify(geometry, 60) AS geometry, name
+    FROM osm_important_waterway_linestring
+    WHERE ST_Length(geometry) > 1000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen1_geometry_idx ON osm_important_waterway_linestring_gen1 USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring_gen1 -> osm_important_waterway_linestring_gen2
+CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring_gen2 AS (
+    SELECT ST_Simplify(geometry, 100) AS geometry, name
+    FROM osm_important_waterway_linestring_gen1
+    WHERE ST_Length(geometry) > 4000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen2_geometry_idx ON osm_important_waterway_linestring_gen2 USING gist(geometry);
+
+-- etldoc: osm_important_waterway_linestring_gen2 -> osm_important_waterway_linestring_gen3
+CREATE TABLE IF NOT EXISTS osm_important_waterway_linestring_gen3 AS (
+    SELECT ST_Simplify(geometry, 200) AS geometry, name
+    FROM osm_important_waterway_linestring_gen2
+    WHERE ST_Length(geometry) > 8000
+);
+CREATE INDEX IF NOT EXISTS osm_important_waterway_linestring_gen3_geometry_idx ON osm_important_waterway_linestring_gen3 USING gist(geometry);

layers/waterway/waterway.sql

@@ -1,89 +1,86 @@
 
 -- etldoc: ne_110m_rivers_lake_centerlines ->  waterway_z3
 CREATE OR REPLACE VIEW waterway_z3 AS (
-    SELECT geom AS geometry, 'river' AS class FROM ne_110m_rivers_lake_centerlines
+    SELECT geom AS geometry, 'river' AS class, name FROM ne_110m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 -- etldoc: ne_50m_rivers_lake_centerlines ->  waterway_z4
 CREATE OR REPLACE VIEW waterway_z4 AS (
-    SELECT geom AS geometry, 'river' AS class FROM ne_50m_rivers_lake_centerlines
+    SELECT geom AS geometry, 'river' AS class, name FROM ne_50m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
 -- etldoc: ne_10m_rivers_lake_centerlines ->  waterway_z6
 CREATE OR REPLACE VIEW waterway_z6 AS (
-    SELECT geom AS geometry, 'river' AS class FROM ne_10m_rivers_lake_centerlines
+    SELECT geom AS geometry, 'river' AS class, name FROM ne_10m_rivers_lake_centerlines
     WHERE featurecla = 'River'
 );
 
--- etldoc: osm_waterway_linestring ->  waterway_z8
+-- etldoc: osm_waterway_linestring_gen3 ->  waterway_z9
-CREATE OR REPLACE VIEW waterway_z8 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
-    WHERE waterway IN ('river') AND ST_Length(geometry) > 10000
-);
-
--- etldoc: osm_waterway_linestring ->  waterway_z9
 CREATE OR REPLACE VIEW waterway_z9 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
+    --SELECT geometry, waterway AS class FROM osm_waterway_linestring_gen3
-    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
+    SELECT geometry, 'river'::text AS class, name FROM osm_important_waterway_linestring_gen3
 );
 
--- etldoc: osm_waterway_linestring ->  waterway_z11
+-- etldoc: osm_waterway_linestring_gen2 ->  waterway_z10
+CREATE OR REPLACE VIEW waterway_z10 AS (
+    SELECT geometry, 'river'::text AS class, name FROM osm_important_waterway_linestring_gen2
+);
+
+-- etldoc: osm_waterway_linestring_gen1 ->  waterway_z11
 CREATE OR REPLACE VIEW waterway_z11 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
+    SELECT geometry, 'river'::text AS class, name FROM osm_waterway_linestring_gen1
-    WHERE waterway IN ('river') AND ST_Length(geometry) > 5000
 );
 
 -- etldoc: osm_waterway_linestring ->  waterway_z12
 CREATE OR REPLACE VIEW waterway_z12 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
+    SELECT geometry, waterway AS class, name FROM osm_waterway_linestring
-    WHERE waterway IN ('river', 'canal') OR (waterway = 'stream' AND ST_Length(geometry) > 1000)
+    WHERE waterway IN ('river', 'canal')
 );
 
 -- etldoc: osm_waterway_linestring ->  waterway_z13
 CREATE OR REPLACE VIEW waterway_z13 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
+    SELECT geometry, waterway::text AS class, name FROM osm_waterway_linestring
-    WHERE waterway IN ('river', 'canal', 'stream', 'drain', 'ditch') AND ST_Length(geometry) > 300
+    WHERE waterway IN ('river', 'canal', 'stream', 'drain', 'ditch')
 );
 
 -- etldoc: osm_waterway_linestring ->  waterway_z14
 CREATE OR REPLACE VIEW waterway_z14 AS (
-    SELECT geometry, waterway AS class FROM osm_waterway_linestring
+    SELECT geometry, waterway::text AS class, name FROM osm_waterway_linestring
 );
 
-
+-- etldoc: layer_waterway[shape=record fillcolor=lightpink, style="rounded,filled",
--- etldoc: layer_waterway[shape=record fillcolor=lightpink, style="rounded,filled",  
 -- etldoc:     label="layer_waterway | <z3> z3 |<z4_5> z4_5 |<z6_7> z6_7 | <z8> z8 |<z9_10> z9_10 |<z11> z11 |<z12> z12|<z13> z13|<z14_> z14_" ] ;
 
 CREATE OR REPLACE FUNCTION layer_waterway(bbox geometry, zoom_level int)
-RETURNS TABLE(geometry geometry, class text) AS $$
+RETURNS TABLE(geometry geometry, class text, name text) AS $$
-    SELECT geometry, class FROM (
+    SELECT geometry, class, name FROM (
-        -- etldoc: waterway_z3 ->  layer_waterway:z3        
+        -- etldoc: waterway_z3 ->  layer_waterway:z3
         SELECT * FROM waterway_z3 WHERE zoom_level = 3
         UNION ALL
-        -- etldoc: waterway_z4 ->  layer_waterway:z4_5        
+        -- etldoc: waterway_z4 ->  layer_waterway:z4_5
         SELECT * FROM waterway_z4 WHERE zoom_level BETWEEN 4 AND 5
         UNION ALL
-        -- etldoc: waterway_z6 ->  layer_waterway:z6_7           
+        -- etldoc: waterway_z6 ->  layer_waterway:z6_8
-        SELECT * FROM waterway_z6 WHERE zoom_level BETWEEN 6 AND 7
+        SELECT * FROM waterway_z6 WHERE zoom_level BETWEEN 6 AND 8
         UNION ALL
-        -- etldoc: waterway_z8 ->  layer_waterway:z8           
+        -- etldoc: waterway_z9 ->  layer_waterway:z9
-        SELECT * FROM waterway_z8 WHERE zoom_level = 8
+        SELECT * FROM waterway_z9 WHERE zoom_level = 9
         UNION ALL
-        -- etldoc: waterway_z9 ->  layer_waterway:z9_10        
+        -- etldoc: waterway_z10 ->  layer_waterway:z10
-        SELECT * FROM waterway_z9 WHERE zoom_level BETWEEN 9 AND 10
+        SELECT * FROM waterway_z10 WHERE zoom_level = 10
         UNION ALL
-        -- etldoc: waterway_z11 ->  layer_waterway:z11        
+        -- etldoc: waterway_z11 ->  layer_waterway:z11
         SELECT * FROM waterway_z11 WHERE zoom_level = 11
         UNION ALL
-        -- etldoc: waterway_z12 ->  layer_waterway:z12        
+        -- etldoc: waterway_z12 ->  layer_waterway:z12
         SELECT * FROM waterway_z12 WHERE zoom_level = 12
         UNION ALL
-        -- etldoc: waterway_z13 ->  layer_waterway:z13        
+        -- etldoc: waterway_z13 ->  layer_waterway:z13
         SELECT * FROM waterway_z13 WHERE zoom_level = 13
         UNION ALL
-        -- etldoc: waterway_z14 ->  layer_waterway:z14_        
+        -- etldoc: waterway_z14 ->  layer_waterway:z14
         SELECT * FROM waterway_z14 WHERE zoom_level >= 14
     ) AS zoom_levels
     WHERE geometry && bbox;

layers/waterway/waterway.yaml

@@ -6,6 +6,7 @@ layer:
       Too short linestrings are filtered out for some zoom levels. Waterways do no not have a `subclass`.
   buffer_size: 4
   fields:
+    name: The OSM [`name`](http://wiki.openstreetmap.org/wiki/Key:name) value of the waterway or the name from Natural Earth for lower zoom levels.
     class: |
         The original value of the [`waterway`](http://wiki.openstreetmap.org/wiki/Key:waterway) tag.
         Can be one of [`stream`](http://wiki.openstreetmap.org/wiki/Tag:waterway%3Dstream),
@@ -15,8 +16,9 @@ layer:
         [`ditch`](http://wiki.openstreetmap.org/wiki/Tag:waterway%3Dditch)`.
   datasource:
     geometry_field: geometry
-    query: (SELECT geometry, class FROM layer_waterway(!bbox!, z(!scale_denominator!))) AS t
+    query: (SELECT geometry, name, class FROM layer_waterway(!bbox!, z(!scale_denominator!))) AS t
 schema:
+  - ./merge_waterway.sql
   - ./waterway.sql
 datasources:
   - type: imposm3