mainstem-sparql

PREFIX schema: <https://schema.org/>
PREFIX gsp: <http://www.opengis.net/ont/geosparql#>
PREFIX wiki: <https://www.wikidata.org/wiki/>
PREFIX hyf: <https://www.opengis.net/def/schema/hy_features/hyf/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

SELECT ?dataset ?variableName ?temporalCoverage WHERE {
  # Bind the @id of the mainstem of interest
  BIND(<https://geoconnex.us/ref/mainstems/1009561> AS ?mainstem)
  
  # Find all monitoring locations that reference the mainstem
  ?monitoringLocation hyf:referencedPosition/hyf:HY_IndirectPosition/hyf:linearElement ?mainstem .

  # Get the datasets for each monitoring location
  ?monitoringLocation schema:subjectOf ?dataset .
  
  # Get the measured variable name and temporal coverage for each dataset 
  ?dataset schema:variableMeasured/schema:name ?variableName ;
           schema:temporalCoverage ?temporalCoverage .

  # Filter datasets by the desired variable name using fuzzier matching
  FILTER(REGEX(?variableName, "stream(flow)?|discharge|flow", "i"))

  # Filter datasets to only include those with a temporal coverage
  # starting before 2018-01-01 and continuing to the present
  FILTER(strdt(?temporalCoverage, xsd:dateTime) <= "2018-01-01T00:00:00"^^xsd:dateTime && 
         STRSTARTS(?temporalCoverage, ".."))
}