Sun Xiang, Zhu Guang-Wei, Da Wen-Yi, Yu Mao-Lei, Yang Wen-Bin, Zhu Meng-Yuan, Xu Hai, Guo Chao-Xuan, Yu Li, Li Heng-Peng, Li Hui-Yun
State Key Laboratory of Lake Environment and Science, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
College of Environmental Science and Engineering, Anhui Normal University, Wuhu 241003, China.
Huan Jing Ke Xue. 2018 Jun 8;39(6):2632-2640. doi: 10.13227/j.hjkx.201710223.
Based on the one-year hourly water temperature profiles and the associated environmental drivers during the past eight years in Shahe Reservoir, Jiangsu Province, China from 2009 to 2016, the factors underlying the seasonal variation of thermal stratification and water quality response were investigated. It was shown that the thermal stratification was a typical subtropical one-cycle mixing model, lasting from May to September. The thermal stratification appeared and disappeared when the surface water temperature was 21 ℃ in the late spring and 19 ℃ in the middle of autumn. The difference between the water temperature at the epilimnion and hypolimnion increased with increasing solar radiation. When the air temperature was above 30 ℃, the stability of the thermal stratification increased. Heavy storms reduced the temperature of the surface water and weakened the temperature stratification of the column above a 5 m depth but had limited impact on the stratification of the hypolimnion deeper than 5 m. The thermal stratification greatly impacted the water quality of the lake. Hypoxia in the bottom water occurred by thermal stratification, leading to increased NH-N. The concentrations of dissolved oxygen, total phosphorus, and suspended solids in the hypolimnion increased after the disappearance of thermal stratification. Our results indicated that the thermal stratification was mainly controlled by solar radiation and the thermal stratification favored the growth of cyanobacteria and led to the release of nutrients from the sediment, threatening the water quality. Attention should be paid to thermal stratification to prevent algal blooms and related water quality deterioration.
基于2009年至2016年中国江苏省沙河水库过去八年的一年 hourly 水温剖面及相关环境驱动因素，研究了热分层季节变化及水质响应的潜在因素。结果表明，热分层是典型的亚热带单周期混合模式，持续时间为5月至9月。热分层在春末地表水温度为21℃和秋中为19℃时出现和消失。表层水和底层水的水温差随太阳辐射增加而增大。当气温高于30℃时，热分层的稳定性增加。暴雨降低了地表水温度，削弱了5米深度以上水柱的温度分层，但对5米以下更深的底层水分层影响有限。热分层对湖泊水质有很大影响。热分层导致底层水缺氧，导致NH-N增加。热分层消失后，底层水中溶解氧、总磷和悬浮固体的浓度增加。我们的结果表明，热分层主要受太阳辐射控制，热分层有利于蓝藻生长并导致沉积物中营养物质释放，威胁水质。应关注热分层以防止藻华和相关水质恶化。
