Effects of Water Temperature on Chlorophyll-a Concentration Stratification in the Tributary Bay of Three Gorges Reservoir

• Published in: Journal of aerospace engineering Vol. 26; no. 4; pp. 667 - 675
• Main Authors: Yu, Zhenzhen, Wang, Lingling, Mao, Jingqiao, Dai, Huichao
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01.10.2013
• Subjects: Mathematical models; Reservoirs; Settling; Stratification; Technical Papers; Tributaries; Turbulent flow; Water quality; Water temperature
• ISSN: 0893-1321; 1943-5525
• DOI: 10.1061/(ASCE)AS.1943-5525.0000254

AbstractThis study aims to quantitatively investigate the formation mechanism of concentration stratification for chlorophyll-a in thermal-stratified water bodies. A well-validated, three-dimensional hydrodynamic-water temperature model was established and applied to simulate the water temperature distribution in Xiangxi Bay (XXB), a representative tributary bay of the Three Gorges Reservoir in China. The numerical results show that temperature stratification with stable vertical temperature profiles seasonally occurred in XXB. Based on these findings, the effect of water temperature stratification on the vertical transport of suspended solids was discussed. Using theoretical derivation and analysis of the relationship between water temperature and the settling velocity of a single spherical solid particle, the settling velocity of suspended solids was significantly affected by temperature under weak turbulence. Therefore, the suspended solids tended to accumulate in the epilimnion or thermocline regions, which could result in the stratification of chlorophyll-a and some other parameters of water quality.