水温分层对水体中悬浮颗粒物垂向输运影响的研究

Study on the Effect of Water Temperature Stratification on Vertical Transport of Suspended Solids

针对三峡水库蓄水后香溪河库湾水温分布特性进行了数值研究。研究表明,香溪河库湾属于季节性水温分层型水体,在分层期会伴有温跃层的出现,在此基础上讨论水温分层对水体中悬浮颗粒物垂向输运的影响。通过推求沉速与水温分布的相关关系,发现水流在紊动条件极其微弱的情况下,水温分层可同时引起悬浮颗粒物的沉降速率呈现梯度分布状态,因此,易造成悬浮颗粒物在温变层的富集,最终将导致物质浓度在垂向上出现分层现象。

The characteristics of water temperature distribution in Xiangxi Bay after the Three Gorges Reservoir had been put into operation were studied by using numerical simulation method.The result showed that the Xiangxi Bay is the water body of seasonal temperature stratification,and the thermocline can be observed in the period of stratification.Furthermore,the effect of water temperature distribution on the vertical transport of suspended solids was discussed.Through deducing the relation of water temperature and settling velocity,it was shown that the settling velocity is significantly affected by temperature,and under the conditions of weak hydrodynamic,the water temperature stratification could result in the gradient distribution of settling velocity,then the suspended solids are enriched at the epilimnion,finally the concentration of substance will be stratified in vertical.