fix(transform): tighten H3 catchment to res 5 (~24km radius)

Res 4 + k_ring(1) gave ~50-60km effective radius, causing Oldenburg to
absorb Bremen (40km away) and destroying score differentiation.

Res 5 + k_ring(1) gives ~24km — captures adjacent Gemeinden (Delmenhorst
at 15km) without bleeding into unrelated cities at 40km+.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Deeman
2026-03-06 14:34:56 +01:00
parent 159d1b5b9a
commit f81d5f19da
2 changed files with 14 additions and 13 deletions

View File

@@ -215,7 +215,7 @@ SELECT
l.location_slug,
l.lat,
l.lon,
h3_latlng_to_cell(l.lat, l.lon, 4) AS h3_cell_res4,
h3_latlng_to_cell(l.lat, l.lon, 5) AS h3_cell_res5,
l.admin1_code,
l.admin2_code,
l.population,

View File

@@ -9,8 +9,9 @@
-- H3 catchment methodology (v3):
-- Addressable market and supply gap now use a regional catchment lens rather than
-- the location's own population/court count. Each location is assigned an H3 cell
-- at resolution 4 (~10km center-to-center). Catchment = cell + 6 neighbours (k_ring=1),
-- covering ~462km² — roughly a 15-18km radius, matching realistic driving distance.
-- at resolution 5 (~8.5km edge). Catchment = cell + 6 neighbours (k_ring=1),
-- covering ~24km effective radius — realistic driving distance without absorbing
-- unrelated cities (e.g. Oldenburg stays separate from Bremen at ~40km).
-- Population and court counts are first aggregated per H3 cell (hex_stats CTE), then
-- summed across the 7-cell ring (catchment CTE) to avoid scanning all 140K locations
-- per location.
@@ -41,27 +42,27 @@ MODEL (
);
WITH
-- Aggregate population and court counts per H3 cell (res 4, ~10km edge).
-- Grouping by cell first (~30-50K distinct cells vs 140K locations) keeps the
-- Aggregate population and court counts per H3 cell (res 5, ~8.5km edge).
-- Grouping by cell first (~50-80K distinct cells vs 140K locations) keeps the
-- subsequent lateral join small.
hex_stats AS (
SELECT
h3_cell_res4,
h3_cell_res5,
SUM(population) AS hex_population,
SUM(padel_venue_count) AS hex_padel_courts
FROM foundation.dim_locations
GROUP BY h3_cell_res4
GROUP BY h3_cell_res5
),
-- For each location, sum hex_stats across the cell + 6 neighbours (k_ring=1).
-- Effective catchment: ~462km², ~15-18km radius — realistic driving distance.
-- Effective catchment: ~24km radius — realistic driving distance.
catchment AS (
SELECT
l.geoname_id,
SUM(hs.hex_population) AS catchment_population,
SUM(hs.hex_padel_courts) AS catchment_padel_courts
FROM foundation.dim_locations l,
LATERAL (SELECT UNNEST(h3_grid_disk(l.h3_cell_res4, 1)) AS cell) ring
JOIN hex_stats hs ON hs.h3_cell_res4 = ring.cell
LATERAL (SELECT UNNEST(h3_grid_disk(l.h3_cell_res5, 1)) AS cell) ring
JOIN hex_stats hs ON hs.h3_cell_res5 = ring.cell
GROUP BY l.geoname_id
)
SELECT
@@ -83,7 +84,7 @@ SELECT
l.padel_venues_per_100k,
l.nearest_padel_court_km,
l.tennis_courts_within_25km,
-- Catchment metrics (H3 res-4 cell + 6 neighbours, ~15-18km radius)
-- Catchment metrics (H3 res-5 cell + 6 neighbours, ~24km radius)
COALESCE(c.catchment_population, l.population)::BIGINT AS catchment_population,
COALESCE(c.catchment_padel_courts, l.padel_venue_count)::INTEGER AS catchment_padel_courts,
CASE WHEN COALESCE(c.catchment_population, l.population) > 0
@@ -94,7 +95,7 @@ SELECT
END AS catchment_venues_per_100k,
ROUND(
-- Addressable market (25 pts): log-scaled catchment population, ceiling 500K.
-- v3: uses H3 catchment population (cell + 6 neighbours, ~15-18km radius) instead
-- v3: uses H3 catchment population (cell + 6 neighbours, ~24km radius) instead
-- of local city population, so mid-size cities surrounded by dense Gemeinden score
-- correctly (e.g. Oldenburg pulls in Ammerland, Wesermarsch, etc.).
25.0 * LEAST(1.0, LN(GREATEST(COALESCE(c.catchment_population, l.population), 1)) / LN(500000))
@@ -109,7 +110,7 @@ SELECT
-- Supply gap (30 pts): INVERTED catchment venue density.
-- v3: uses catchment courts / catchment population instead of local 5km count / city pop.
-- 0 courts/100K across the ~15-18km ring = full 30 pts (genuine white space).
-- 0 courts/100K across the ~24km ring = full 30 pts (genuine white space).
-- ≥8/100K = 0 pts (well-served regional market).
+ 30.0 * GREATEST(0.0, 1.0 - COALESCE(
CASE WHEN COALESCE(c.catchment_population, l.population) > 0