Spatiotemporal patterns of surface-suspended particulate matter in the Three Gorges Reservoir

摘要

An investigation was conducted in the Three Gorges Reservoir (TGR) seasonally from September 2010 to June 2011 to screen the distribution pattern of suspended particulate matter (SPM). Concentration of SPM, particulate nitrogen (PN), particulate phosphorus (PP), bioavailable particulate phosphorus (BAPP), and chlorophyll a (Chl a) were determined synchronously. Concentration of SPM was higher in the flood season than in the dry season and higher in the mainstream than in the tributaries. Chl a, PN, PP, and BAPP showed similar temporal pattern with SPM distribution. Particulate elements were significantly correlated with concentrations of SPM (p < 0.05). The proportion of algae-derived SPM in total SPM was higher in the tributaries than that in the mainstream. The results revealed that the spatiotemporal heterogeneity determined by hydrodynamics was the characteristic of SPM distribution. The source of SPM was mostly allochthonous. It could be deduced that SPM was an important factor affecting the water quality and algal growth in TGR by releasing or absorbing particulate nutrient.