UM Geospatial Digital Special Collections

Citation: Miami-Dade County-FEMA (2015). Miami-Dade Flood Hazard (FEMA) [gis dataset]. Miami-Dade County. https://gis-mdc.opendata.arcgis.com/datasets/MDC::fema-flood-zone/about. last updated: 2024-10-28 (update frequency: 10 years). Abstract: A polygon feature class of Federal Emergency Management Agency (FEMA) flood hazard zones within Miami-Dade County Key words: Miami-Dade County, FEMA, Environment, Emergency, Flood, Flood Hazard, Hazard, Natural Disaster, Public-Safety Open Geospatial Consortium Standards: dynamic vector tiles | | WMS (coming soon) | WFS (coming soon) ESRI Standards: ArcGIS MapServer | ArcGIS FeatureServer | Open in ArcGIS Portal for GDSC Analytical Functions: gdsc_get_attributes(tablename=mdc_flood_hazard,lat=25.718,lng=-80.279,identifier=fzone,attrs=[fzone,zonesubty,elev],normal='') gdsc_nearest_neighbor(table=mdc_flood_hazard,lat=25.718,lng=-80.279,id=fzone) ETL documentation

ETL for mdc_flood_hazard

######### # GDSC ETL is performed in two steps: shell script to ETL data into postgres # and then additional transformations with SQL in postGIS (if needed). #### ######### # Step 1 - bash script (pseudo code) #### # create directory structure and move into it mkdir -p /data/mdc_flood_hazard/{download,etl} && cd /data/mdc_flood_hazard # set update flag based on last update and update frequency do_update=0 if date() < last_update + update_frequency else do_update = 1 # download if update flag is set: if do_update == 1 then wget -O download/mdc_flood_hazard.json 'https://opendata.arcgis.com/api/v3/datasets/ef3bdd041b2e424695eb4dfe965966c4_0/downloads/data?format=geojson&spatialRefId=4326&where=1%3D1' # replace column names Shape__Length and Shape__Area to avoid conflict when # providing as service on ArcServer. sed -i 's/Shape__Length/shape_length/gI; s/Shape__Area/shape_area/gI' download/mdc_flood_hazard.json # load into postGIS with: ogr2ogr -lco GEOMETRY_NAME=geom -f PostgreSQL PG:"" download/mdc_flood_hazard.json -nlt multipolygon -nln mdc_flood_hazard ######### # Step 2 - SQL script (pseudo code): #### # remove duplicate points and make geometries valid: UPDATE mdc_flood_hazard SET geom=ST_MakeValid(ST_RemoveRepeatedPoints(geom));" # add local geometry column and reproject existing geometries into local EPSG: SELECT AddGeometryColumn ( 'mdc_flood_hazard', 'geom_local',2236,'multipolygon',2 ); UPDATE mdc_flood_hazard SET geom_local=ST_MakeValid(ST_RemoveRepeatedPoints(ST_Transform(ST_Multi(geom),2236))); CREATE INDEX mdc_flood_hazard_geom_local_idx ON mdc_flood_hazard USING GIST (geom_local); NOTIFY pgrst, 'reload schema';"cd /data/mdc_flood_hazard/ mkdir -p derived # Create pg_dump and downloadable zip of table in derivate directory pg_dump -d $POSTGRES_DB -U $POSTGRES_USER -p $POSTGRES_PORT -h postgis-gaxfbdigubom2fwo -t mdc_flood_hazard > derived/mdc_flood_hazard.sql tar -czf derived/mdc_flood_hazard.sql.tar.gz meta_dcat_mdc_flood_hazard.json -C derived mdc_flood_hazard.sql