ABSTRACT
The recovery of water temperature and Dissolved Oxygen (DO) of the bottom layer water of a stratified reservoir along the downstream river remains poorly understood. In this study, a field investigation and an experiment were carried out on the test section on the Wenxia River. Water temperature and DO were measured and macro invertebrates were sampled along the test section. Effects of step-pool and sand bar on reaeration ability were inspected in the experiment. The results showed that (1) water temperature and DO increase along the river; and water temperature is more susceptible to channel width than DO; (2) downstream species diversity of macroinvertebrates increases with the reaeration process of the stream; (3) discharge has an influence on the diurnal variation of reaeration capability for a steppool channel because of high variance of submergence under different discharges; (4) DO is transversely distributed downstream a sand bar, high at the tail but low in the two tributaries flowing by.
