How many {drainage basin} are to/by {Chad Basin} ?
What is the number of drainage basins by Chad Basin?
How many drainage basins are by Chad Basin?
SELECT ( COUNT ( ?j ) AS ?s ) { ?j property:drainage_basin resource:Chad_Basin }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P4614> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q575245 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P4614 wd:Q575245 }
14