Abstract
水体浊度是影响水下光场及营养盐循环的关键要素之一,其变化过程与水生生态环境演变关系密切.基于2015-2016年7个时段于太湖贡湖湾内外的金墅和上山村两站点的水体浊度及东山气象站的逐时风场数据,利用分位统计等方法,探讨了风速、风向及时间累积效应对水体浊度的影响.结果表明:在以风场驱动为主要动力来源的大型浅水湖泊中,春、秋两季水体浊度的变化频率高于夏、冬两季,且春季变率更为突出;冬季风场和水体浊度的变率均较夏季明显.风场(包括风速、风向及其累积时间)是影响水体浊度变化的关键因素.其中风速是主要决定性因子;风向对水体浊度有较明显的影响,其通过对风速效应的修正进而影响水体浊度,该修正作用可用三角函数表征;水体浊度变化同时还受前期风场累积的影响,其前期时间累积效应的有效时段为2~10 h.该研究给出了风速、风向及风场累积效应的耦合对水体浊度的影响模型,有助于弄清风场对水体浊度变化的影响机制.;Turbidity is one of the key factors that affect the underwater light climate and nutrient circulation, and its change is closely related to the evolution of aquatic ecosystem. Based on the turbidity data at the two sites near Jinshu and Shangshan Village in Gonghu Bay of Lake Taihu from 2015 to 2016 and the hourly wind field measurement in Dongshan weather station, the effects of wind speed, wind direction and wind duration on turbidity was analyzed with quantile regression technique. The results show as follows. In large shallow lakes where wind as the primary driving force, the turbidity change frequency in spring and autumn is higher than that in summer and winter, with spring as the most prominent. The change of water turbidity in winter is more obvious than that in summer. The variability of wind field (the speed, direction and duration), particularly the wind speed, is the key factor regulating turbidity. The wind direction can affect the turbidity by the correction of the wind speed. The correction can be characterized by a trigonometric function. The turbidity was mainly affected by the northern wind, and followed by the east-west wind. The influence of the south wind is the weakest. The change of turbidity is influenced by the wind field preceding measurement time, and the valid wind duration is about 2-10 hours. This study developed a model elucidating the influence of wind speed, wind direction and wind duration on the turbidity, which is helpful to clarify the mechanism on turbidity variation in Lake Taihu.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have