Diel variation of dissolved organic carbon during large flow events in a lowland river

Diel variation in dissolved organic carbon (DOC) within lotic systems has been reported on numerous occasions. However, to our knowledge there has been no published work on diel DOC variation within lowland rivers during high flow events. We sampled DOC at 4h intervals from two sites across two distinct flow regimes in the regulated lower Namoi River, Australia. This included a large flood (mean flow 224m 3s -1 and a peak flow of 376m 3s -1) sampled every 4h for 10 consecutive days. DOC concentrations were significantly greater at night than during the day (P