Study on Seasonal Characteristics of Thermal Stratification of a Large-scale Reservoir in South Subtropical China
Xinfengjiang Reservoir is a typical large-scale oligotrophic subtropical reservoir in southern China.The investigation on the seasonal and vertical dynamics of water temperature,dissolved oxygen(DO),pH value,total phosphorus(TP),total nitrogen(TN),permanganate index(IMn)and chlorophyll a(Chl.a)was conducted from March 2020 to February 2021 in order to find out the seasonal stratification characteristics of Xinfengjiang Reservoir.Results showed that the reservoir had a significant seasonal thermal stratification in summer and autumn,and the thermal stratification period was during May to the end of October,and the mixed period were during January to April and during November to December.Thermal stratification had influences on vertical distribution of DO,pH value,TN,IMn and Chl.a.Strong stratification of DO and seasonal hypoxia didn't appear,the DO value of surface water was higher than class Ⅰ level(7.5 mg/L)set by"Environmental quality standards for surface water"(GB 3838-2002),but the DO value of thermocline layer descended from Class Ⅰ to Class Ⅱ-Ⅲ.It indicates that it may face potential ecological risks,which is not conducive to the stability of the aquatic ecological environment system.
ReservoirWater stratificationSouth subtropicsVertical distribution
万方数据
维普
