LU Dingpan1,2, WANG Jingfu1, CHEN Jingan1, ZHANG Ruiyu1, YANG Haiquan1,ZHOU Yinhong1,2, JIN Zuxue3
(1.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550081, China；
2.University of Chinese Academy of Sciences, College of Resources and Environment, Beijing 100049, China；
3.Guizhou University, College of resources and environmental engineering, Guiyang 550025, China)
Abstract: The vertical structure of water temperature is an important basis for the evolution of lake/reservoir ecosystem. The stability of thermal stratification has important impacts on physical, chemical and biological evolutions of deep-water lakes and reservoirs. Therefore, it is of great significance to study the characteristics and key control factors of water thermal stratification. In this study, the DYRESM hydrodynamic model was applied to simulate the water temperature variation of the Hongfeng Reservoir in 2014, and the key factors affecting the water thermal stratification were explored. Our results showed that: 1) the DYRESM model can effectively simulate the characteristics and time evolution of the water thermal stratification and can accurately predict the formation and extinction of the thermal stratification and the intensity of de-stratification. 2) the temperature changes have significant impacts on the thermal stratification, and the increasing temperature can accelerate the formation of the water thermal stratification, resulting in the thermocline submergence and the delay of de-stratification. The enhancement of shortwave radiation (<40%) will not significantly affect the water temperature structure, but may cause the time delay of de-stratification. The wind speed is a sensitive factor of the thermal stratification stability. When the wind speed increases by 40%, the water temperatures in the middle and bottom waters will increase significantly (from 9 to 14℃) from June to September, and the de-stratification will occur 30 days earlier, correspondingly, the stratification period will be shortened.
Key words: Thermal stratification; DYRESM model; Air temperature; Shortwave radiation; Wind speed; Hongfeng Reservoir
EARTH AND ENVIRONMENT Vol.47, No.2, Tot No.328, 2019, Page 131-140
