Causal analysis of the spatial-temporal variation of water quality in Baiyangdian Lake
白洋淀水质时空变化及影响因子评价与分析

As an important lake in the Haihe river basin,the Baiyangdian Lake plays an important role in the ecological health and environmental safety of the whole basin.To investigate the spatial-temporal variation of the water quality and the main factors affecting the quality,we employed grey clustering,comprehensive pollution index and single factor pollution indexes.The results showed that the water quality of Baiyangdian Lake has generally decreased since 1973.Specifically,the proportion of water with worse qua...