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Merged
paigewilliams merged 3 commits into from
Sep 3, 2026
Merged

Change geocoder to use OSM #145

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5fe3ff8
use osm geocoder instead of arcgis
paigewilliams Aug 31, 2026
47c697c
support multiple locations in the STUDY_REGION['context']
paigewilliams Sep 1, 2026
aa48af8
support STUDY_REGION.contextual_hits and STUDY_REGION.context
paigewilliams Sep 1, 2026
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146 changes: 85 additions & 61 deletions landmapper/app/views.py
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Original file line number Diff line number Diff line change
Expand Up @@ -77,7 +77,7 @@ def unstable_request_wrapper(url, params=False, retries=0):
contents = False
return contents

def geocode(search_string, srs=4326, service='arcgis', with_context=False):
def geocode(search_string, srs=4326, service='osm', with_context=False):
# """
# geocode
# PURPOSE: Convert a provided place name into geographic coordinates
Expand All @@ -86,10 +86,11 @@ def geocode(search_string, srs=4326, service='arcgis', with_context=False):
# - srs: (int) The EPSG ID for the spatial reference system in which to output coordinates
# - defaut: 4326
# - service: (string) The geocoding service to query for a result
# - default = 'arcgis'
# - other supported options: 'google'
# - default = 'osm' (Open Street Map Nominatim)
# - 'arcgis' (ArcGIS World Geocoding Service)
# - with_context: (bool) Whether to include contextual hits if no direct hits are found
# OUT:
# - coords: a list of two coordinate elements -- [lat(y), long(x)]
# - coords: a list of two coordinate elements -- [lat(y), lon(x)]
# - projected in the requested coordinate system
# CALLED BY:
# - identify
Expand All @@ -99,64 +100,87 @@ def geocode(search_string, srs=4326, service='arcgis', with_context=False):
g_hits = []
hit_names = []

# Query desired service
# TODO: support more than just ArcGIS supplied geocodes
# Use other services if no matches are found.
# if service.lower() == 'arcgis':
g_matches = geocoder.arcgis(search_string, maxRows=100)
for match in g_matches:
if (match.latlng[0] <= settings.STUDY_REGION['north'] and
match.latlng[0] >= settings.STUDY_REGION['south'] and
match.latlng[1] <= settings.STUDY_REGION['east'] and
match.latlng[1] >= settings.STUDY_REGION['west']):
if not match.raw['name'] in hit_names:
g_hits.append(match)
hit_names.append(match.raw['name'])
for hit in g_hits:
hits.append({
'name': hit.raw['name'],
'coords': hit.latlng,
'confidence': hit.confidence
})

if not with_context:

if len(hits) == 0:
for context in settings.STUDY_REGION['context']:
new_hits = geocode("%s%s" % (search_string, context), srs=srs, service=service, with_context=True)
for hit in new_hits:
if not hit['name'] in hit_names:
hits.append(hit)
hit_names.append(hit['name'])
# TODO: If new hits match but have better confidence, replace

# Transform coordinates if necessary
if not srs == 4326:

if ':' in srs:
if service.lower() == 'arcgis':
g_matches = geocoder.arcgis(search_string, maxRows=100)
for match in g_matches:
if (match.latlng[0] <= settings.STUDY_REGION['north'] and
match.latlng[0] >= settings.STUDY_REGION['south'] and
match.latlng[1] <= settings.STUDY_REGION['east'] and
match.latlng[1] >= settings.STUDY_REGION['west']):
if not match.raw['name'] in hit_names:
g_hits.append(match)
hit_names.append(match.raw['name'])
for hit in g_hits:
hits.append({
'name': hit.raw['name'],
'coords': hit.latlng,
'confidence': hit.confidence
})

if not with_context:

if len(hits) == 0:
for context in settings.STUDY_REGION['context']:
new_hits = geocode("%s%s" % (search_string, context), srs=srs, service=service, with_context=True)
for hit in new_hits:
if not hit['name'] in hit_names:
hits.append(hit)
hit_names.append(hit['name'])
# TODO: If new hits match but have better confidence, replace

# Transform coordinates if necessary
if not srs == 4326:

if ':' in srs:
try:
srs = srs.split(':')[1]
except Exception as e:
pass
try:
srs = srs.split(':')[1]
except Exception as e:
pass
try:
int(srs)
except ValueError as e:
print(
'ERROR: Unable to interpret provided srs. Please provide a valid EPSG integer ID. Providing coords in EPSG:4326'
)
return coords

hits_transform = []
for hit in hits:
coords = hit.latlng
point = GEOSGeometry('SRID=4326;POINT (%s %s)' %
(coords[1], coords[0]),
srid=4326)
point.transform(srs)
coords = [point.coords[1], point.coords[0]]
hits_transform.append(coords)
hits = hits_transfrom

int(srs)
except ValueError as e:
print(
'ERROR: Unable to interpret provided srs. Please provide a valid EPSG integer ID. Providing coords in EPSG:4326'
)
return coords

hits_transform = []
for hit in hits:
coords = hit.latlng
point = GEOSGeometry('SRID=4326;POINT (%s %s)' %
(coords[1], coords[0]),
srid=4326)
point.transform(srs)
coords = [point.coords[1], point.coords[0]]
hits_transform.append(coords)
hits = hits_transform

elif service.lower() == 'osm':
headers = {
"User-Agent": "Landmapper (Contact: ksdev@ecotrust.org)",
"Referer": "https://landmapper.ecotrust.org/"

@rhodges rhodges Sep 2, 2026

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Hrm. This might be oregon.landmapper.ecotrust.org or washington.landmapper.ecotrust.org. It's probably best to leave this alone for now, rather than insert a constant from .env/settings.py.

}
g_matches = requests.get('https://nominatim.openstreetmap.org/search', params={'q': search_string, 'format': 'json', 'limit': 100}, headers=headers).json()
for match in g_matches:
if (float(match['lat']) < settings.STUDY_REGION['north'] and
float(match['lat']) > settings.STUDY_REGION['south'] and
float(match['lon']) < settings.STUDY_REGION['east'] and
float(match['lon']) > settings.STUDY_REGION['west']):
if not match['display_name'] in hit_names:
g_hits.append(match)
hit_names.append(match['display_name'])
for hit in g_hits:
hits.append({
'name': hit['display_name'],
'coords': [float(hit['lat']), float(hit['lon'])],
'confidence': hit.get('importance', 0)
})

if not with_context:
if len(hits) == 0:
# default to the center of the state if no hits are found and with_context is False
hits.extend(settings.STUDY_REGION['contextual_hits'])

hits = sorted(hits, key = lambda i: i['confidence'], reverse=True)
if len(hits) > 5:
hits = hits[:5]
Expand Down
25 changes: 24 additions & 1 deletion landmapper/landmapper/settings.py
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Original file line number Diff line number Diff line change
Expand Up @@ -261,6 +261,18 @@
'context': [
', OR',
', Oregon USA',
],
'contextual_hits': [
{
'name': 'OR',
'coords': [43.9909179,-120.6359984],
'confidence': 1
},
{
'name': 'Oregon',
'coords': [43.9909179,-120.6359984],
'confidence': 1
}
]
},
'WA': {
Expand Down Expand Up @@ -289,7 +301,18 @@
'context': [
', WA',
', Washington USA',
# ', WA',
],
'contextual_hits': [
{
'name': 'WA',
'coords': [47.273118,-120.824902],
'confidence': 1
},
{
'name': 'Washington',
'coords': [47.273118,-120.824902],
'confidence': 1
}
]
}
}
Expand Down
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