Author(s): Xinghua Li; Dan Dai; Xiangqin Xu; Guoxian Huang; Mingdong Sun; Tong Wang; Honggang Yuan
Linked Author(s): GuoXian Huang
Keywords: No keywords
Abstract: Dahuofang reservoir is one of the most important drinking water sources in Liaoning province, China. Dynamics of total phosphorus (TP) concentration, flux and related retention processes in this reservoir are very important to the water quality management and drinking water safety. Based on the monitoring data of meteorology, hydrology, water quality and sediment from the main stations during 1992-2017, this paper analysed the TP fluxes in the different boundaries and the stocking process in both the overlying water and the active surface sediment layer using the mass balance method. This study revealed the TP accumulation variation in the overlying water and the surface sediment layer and the controlling mechanism of TP concentration in overlying water under different hydrological conditions. The results showed that the combination of flood and dry hydrological rhythms is important to maintain the dynamic balance of TP in the reservoir. Based on these results, to reduce the TP retention rate and accumulated TP in the active surface sediment layer, we put forward suggestions on environmental optimization operations during the early days of large flood and subsequent small flood season by opening the deep flood discharging holes of the reservoir and lowering upstream water level. These results provide an improved understanding and new eyesight of the nutrient control of large reservoirs in the north China.