A novel framework for turbidity source apportionment of the urban lakeside river network

•A turbidity source analysis framework was proposed for the urban lakeside river network.•Turbidity problem was largely SIM-driven, followed by SOM and other matters.•The Tiaoxi River and shipping both provided 34% of total TSS load.•The turbid Lake Taihu provided 31% of total TSS load.•TSS source respond strongly to the storm events and COVID-19 lockdown.