Meaning of 依 in 大凉山失依孤儿
失依 is actually 失去依靠, in english this means "lost dependence", or specifically those orphan who cannot find anyone to help them get on with their lives, probably because the basic welfare and rescuing  system is broken there. If there is only one character 失, then the title does not make sense semantically indeed [or one might understand it as "Daliangshan lost orphans", but this is weird]. Google translator might simply ignore the character 依 and just translate 失 into "lost". Better translations could be 


  The orphans who have no one to depend in Daliangshan Mountain 


here the name of the place would be incorrect, but this seems not influence the meaning.