Impact of river morphology on urban river self-purification capacity in Guangzhou

A river morphology assessment system with seven indexes,channel fractal dimension,channel sectional morphology,riverbank substrate,riparian width, riparian vegetation coverage,riverbed material,and riverbed habitat complexity,was constructed and used to study the effect of river morphology on the river self-purification capacity of Wuyong Stream in Guangzhou through regular water quality monitoring.The results showed that this system can reflect the morphology differences among the reaches.The BOD5 degradation coefficient and alongpath degradation rate of several water quality indexes in different reaches showed significant differences.The reach with the higher river morphology index value had a better self-purification capacity.River morphology had a correlation with the degradation of NH+4-N,SS,DO,and turbidity,which was an important factor for river self-purification.