Grain size distributions of the riverbed surface of an alpine section of the Drava River in 2018

This is a data set related to a bedload tracer field study in an alpine section of the Drava River between 11 May 2017 and 11 June 2018. It contains the grain size distributions of the riverbed surface at 9 locations in the Upper Drava River. In the related publication the median grain size of the riverbed surface near the seeding site served to obtain the relative grain sizes of the bedload tracers.