To do it for an individual civ you would do it like this in SQL:
INSERT INTO Modifiers
(ModifierId, ModifierType, RunOnce, Permanent, OwnerRequirementSetId, SubjectRequirementSetId)
VALUES ('QUO_BIOME_ARABESQUE_GIANT_STOCKPILE', 'MODIFIER_PLAYER_ADJUST_RESOURCE_STOCKPILE_CAP', 0, 0, NULL, NULL) ;
INSERT INTO ModifierArguments
(ModifierId, Name, Type, Value, Extra, SecondExtra)
VALUES ('QUO_BIOME_ARABESQUE_GIANT_STOCKPILE', 'Amount', 'ARGTYPE_IDENTITY', '150', NULL, NULL) ;
INSERT INTO TraitModifiers
(TraitType, ModifierID)
VALUES ('QUO_TRAIT_BIOME_ARABESQUE', 'QUO_BIOME_ARABESQUE_GIANT_STOCKPILE' ) ;
TraitType in the final piece of SQL would need to be a traittype of a Civilization or Leader.