Excitation-emission matrix fluorescence spectra of chromophoric dissolved organic matter reflected the composition and origination of dissolved organic carbon in Lijiang River, Southwest China

•EEM-PARAFAC CDOM compounds were used to illustrate DOC composition and origination.•Soil-, aquatic plant- and microbial sourced organic matter existed in Lijiang river.•Aquatic plant- and microbial sourced Autochthonous DOC dominated in downstream.•Precipitation and T induced seasonal variation of soil- and aquatic plant sourced OC.•DIC fertilization effects induced spatial increase of autochthonous OC.