Impact of intra-annual runoff uniformity and global warming on the thermal regime of a large reservoir
Impact of intra-annual runoff uniformity and global warming on the thermal regime of a large reservoir
复制标题
年内径流均匀性和全球变暖对大型水库热力状况的影响
DOI：
10.1016/j.scitotenv.2018.12.207
复制
发表时间：
2019-03-25
影响因子：
9.8
通讯作者：
Chen, Sheng
中科院分区：
文献类型：
--
作者：
He, Wei;Lian, Jijian;Chen, Sheng
热分层现象在储层中很常见，对水环境影响很大。年内径流均匀性的变化已经在几个流域中发现，但很少有研究集中在这些变化对热状态的影响上。利用1950 ~ 2015年中国三板溪水库径流数据，统计分析了20世纪50年代和20世纪90年代径流均匀性的长期趋势，并进行了外推，探讨了这些趋势与水库热态的关系。此外，对考虑全球变暖的未来气候情景的热状态进行了评估。研究结果表明：1)在华南地区，三板溪水库等自然流域的年内径流分布集中度（C-d）趋于较高，而在受人类活动影响较大的河流中，C-d趋于较低。2) C-d的升高与储层温度和放水温度升高有关，与热稳定性降低有关。三板溪水库G值每增加10%，年平均气温、热稳定性和放水温度分别变化0.036℃、-48.4 J m（-2）和0.153℃。这些变化在夏季比其他季节更大；3)全球变暖导致水库温度、放水温度和热稳定性升高，对这些参数的影响比年际径流均匀性更显著；4)未来的温度变化将加剧氧气分层和低代谢缺氧，促进藻华，推迟鱼类产卵。分析了通过改变水库运行水位和进水口标高两种方法控制水库热态的效果。研究了三板溪水库热态对气候变化的响应，为水库水温和水环境的管理提供理论支持。(C) 2018年Elsevier B.V.出版
Thermal stratification is common in reservoirs and greatly influences the aquatic environment. Changes in the uniformity of intra-annual runoff have been detected in several basins, but few studies have focused on the impacts that these changes have on thermal regimes. Using runoff data for Sanbanxi Reservoir, China, during 1950-2015, the long-term trends of intra-annual runoff uniformity were statistically analyzed and extrapolated for the 2050s and 2090s, and the relationship between these trends and the thermal regime of the reservoir were investigated. Moreover, the thermal regime was evaluated for future climate scenarios accounting for global warming. This study shows the following: 1) for South China, the concentration degree (C-d) for the distribution of intra-annual runoff in natural basins such as Sanbanxi Reservoir tended to be higher, but for rivers significantly impacted by human activities, C-d tended to be lower. 2) a higher C-d was associated with an increased reservoir temperature and released water temperature, and decreased thermal stability. For Sanbanxi Reservoir, a 10% increase in G corresponded to a change in annual average temperature, thermal stability, and released water temperature of 0.036 degrees C, -48.4 J m(-2), and 0.153 degrees C, respectively. These changes were larger in summer than in other seasons; 3) global warming is predicted to increase reservoir temperature, released water temperature, and thermal stability, having a more significant influence on these parameters than infra -annual runoff uniformity; 4) future changes in thermal regimes will intensify oxygen stratification and hypolimnetic anoxia, promoting algal blooms, and delaying fish spawning. Effects of two methods aimed at controlling the thermal regime were also analyzed, including changing the operation level and intake elevation of the reservoir. This study investigated the response of the thermal regime of Sanbanxi Reservoir to climate change, and provides theoretical support for the management of water temperature and the reservoir's aquatic environment. (C) 2018 Published by Elsevier B.V.