垂向湍流扩散和光耦合对下沉藻增长的影响——基于内陆混浊湖泊(太湖)分析
Effect of vertical turbulent diffusion and light coupling on the growth of sinking algae——Analysis based on inland turbid lakes (Lake Taihu)

周妍赵巧华刘鹏

文摘	在假设温度恒定､弱化营养盐限制作用的条件下,利用太湖背景漫射衰减系数､日变化太阳辐射等数据,通过下沉藻生长与水环境相结合的耦合模型,模拟下沉藻增长过程中垂向湍流扩散和光之间的耦合.结果表明:在相对清洁水体中(背景漫射衰减系数小于1.1/m),下沉藻类无需垂向湍流扩散均可维持增长;混浊水体中(背景漫射衰减系数介于1.1~3.0/m)下沉藻类增长需垂向湍流扩散维持,且最低垂向湍流扩散值随背景漫射衰减系数增大而增大,二者间存在指数函数关系;最低垂向湍流扩散(D)､水深(z)与藻类下沉速度(v)间的佩克莱数应位于0.38~13.89,否则垂向湍流扩散对比其他因素(藻类沉降和光衰减),对水柱中下沉藻类的增长的作用甚小;当背景漫射衰减系数大于3.0/m,水柱平均光能可能难以满足藻类增长,藻类持续消亡.该研究有助于厘清气候变化背景下水生生态系统中的浮游植物种群演替机制.
其他语种文摘	Based on the assumption of constant temperature and no nutrient salt limitation, a mathematical model coupling sinking algae growth and water environment of Lake Taihu was used to investigate the effect between the vertical turbulent diffusion and background diffused attenuation coefficient(Kbg) on the growth of sinking algae. The simulation results showed that the total biomass growth of the sinking algae could be sustained without vertical turbulent diffusion in the relatively clean water (Kbg was less than 1.1/m); in turbid water (Kbg was between 1.1~3.0/m), the growth required vertical turbulent diffusion to maintain, and the minimum vertical turbulence diffusion increased with the Kbg. The Peclet number between the minimum vertical turbulence diffusion(D), water depth(z) and the algae sinking speed(v) should between 0.38~13.89, otherwise the minimum vertical turbulence would have little effect on the growth than other factors (for example, algae sinking speed or light attenuation). When the Kbg was greater than 3.0/m, the light intensity of the water column was too low to maintain the total biomass growth of algae. This paper helped to clarify the phytoplankton population succession mechanism in aquatic ecosystems under climate change.
来源	中国环境科学 ,2019,39(2):792-801 【核心库】
关键词	下沉藻 ; 垂向湍流扩散 ; 背景漫射衰减系数 ; 数值模拟
地址	南京信息工程大学水文与水资源工程学院, 江苏, 南京, 210044
语种	中文
文献类型	研究性论文
ISSN	1000-6923
学科	环境污染及其防治
基金	国家自然科学基金
文献收藏号	CSCD:6425867