"Harvey" is the name of a hurricane which recently hit Texas, so "Harvey victims" are those who've been affected by the hurricane.

This refers to Hurricane Harvey. "He pitches in at a shelter (provided) for (hurricane) Harvey victims."

Just to expand on Carrie's answer, Harvey is a well known first name for a boy(although it's old fashioned and few babies are named Harvey any longer.) Hurricanes are given first names like this ascending alphabetical order for each major storm of the year. You can see the list for all the hurricane names for 2017 here > http://www.nhc.noaa.gov/aboutnames.shtml Note that they alternate genders.