Analysis of Water Quality Change Characteristics and Pollution Causes in Tongxiang Section of Canal
The Beijing-Hangzhou Grand Canal is the north and south water transportation hub, the Tongxiang Section of the Canal (TXSC) is located at the most upstream of the Beijing-Hangzhou Grand Canal, Tongxiang City is a concentrated drinking water source. Although the annual water quality of each control section in Tongxiang Section of the Canal can reach the standard stably, the monthly monitoring sometimes shows that low dissolved oxygen (DO) or total phosphorus (TP) ex-ceeds the standard. In this study, water quality monitoring was carried out three times in May 2020 (normal water season), June 2020 (wet season) and December 2020 (dry season) on the main stream of Tongxiang Section of the Canal, and the spatio-temporal variation of conventional water quality indexes was studied. The reasons of exceeding the standard of low dis-solved oxygen and total phosphorus in Tongxiang Section of Canal were analyzed briefly. The results show that the key control areas affecting the DO standard are: the inlet water of hemp ferry and the monitoring site section 11~13. Key control areas affecting TP standards are: monitoring sites 5~7, 8~9, and 18~24. The decrease of DO concentration in water body is greatly influenced by upstream water inflow, and TP pollution in Tongxiang canal mainly comes from Tongxiang itself.
Tongxiang Section of the Canalwater quality monitoringcause of pollution