基于Delft3D的东平湖营养盐和叶绿素a时空分布特征OA

To investigate the spatiotemporal distribution characteristics of nutrients and chlorophyll-a in Dongping Lake,a coupled hydrodynamic-water quality-aquatic ecosystem model was constructed based on Delft3D.This model simulated indicators including total nitrogen,nitrate nitrogen,ammonium nitrogen,total phosphorus,soluble reactive phosphate and chlorophyll-a.After validating the model's reliability,we systematically analyzed the spatiotemporal distribution patterns of nutrients and chlorophyll-a along with their influencing factors,revealing the migration and transformation patterns of nitrogen and phosphorus.The results showed that nutrients and chlorophyll-a concentrations in Dongping Lake changed in three stages:relatively stable from January to April,significant fluctuations from May to August,and gradual decline toward stability from September to December,and the peaks of different indicators appeared at different times.Spatially,a general"higher in the south,lower in the north"distribution pattern was observed,though ammonium nitrogen,total phosphorus,and chlorophyll-a exhibited an inverse"higher in the north,lower in the south"distribution during certain periods.Exogenous inputs and internal environmental factors jointly influenced the spatiotemporal distribution of nutrients and chlorophyll-a.Exogenous inputs,primarily from Dawen River,dominated the overall distribution pattern,while environmental factors such as water temperature,dissolved oxygen,and hydrodynamic conditions further refined the internal variations.Nitrogen and phosphorus had different fates during their migration and transformation processes.Nitrogen is primarily removed from the system through denitrification reactions,whereas phosphorus tended to convert to particulate forms and remained long-term within the lake body.The results of this study provided valuable references for implementing precise water quality management in Dongping Lake.