闽江口硅藻-盐度转换函数建立

Establishment of diatom-salinity transfer function in Minjiang Estuary

目前国内利用定量分析的方法研究河口区古环境屈指可数,闽江口尚缺乏相关研究,本研究旨在闽江口建立硅藻-盐度转换函数,为今后研究闽江口古环境提供科学依据。在对闽江口表层沉积硅藻进行CCA分析后,结果表明盐度对硅藻属种变化具有最大解释量,并在研究区划分出4个区,Ⅰ区硅藻分布受河口外沿岸水体影响;Ⅱ区硅藻分布受潮汐上溯海水入侵影响;Ⅲ区硅藻分布受到潮汐与径流共同影响;Ⅳ区硅藻分布主要受径流影响。通过剔除异常站位及模型比选等手段确定最优硅藻-盐度转换函数为WA-PLS模型下Component 5模型,转换函数关系式为S拟=0.25+1.007S实,并以2.76的平均误差作为补偿提升转换函数精度。

At present, application of quantitative analysis methods to study the paleo-environment in estuary area is rare in China, particularly in Minjiang Estuary. The purpose of this paper is to establish the diatom-salinity transfer function in Minjiang Estuary for the future study of paleoenvironment in this area. The CCA analysis on the surface sediment diatoms from Minjiang Estuary showed that the salinity had the best interpretation for the changes of diatoms. Thus, the estuary and its adjacent sea areas can be divided into four areas. The distribution of diatoms in area I was affected by the coastal waters outside the estuary. The distribution of diatoms in area II was impacted by the intrusion of tidal seawater. The distribution of diatoms in area III was affected by both tide and runoff and the distribution of diatoms in area IV was mainly impacted by runoff. Removed the abnormal station and with model comparison, the optimal transfer function was determined as the Component 5 model under the WA-PLS model. The transfer function relationship was S (fitting)= 0.25 + 1.007 S (real), and the average error of 2.76 was used as the compensation to improve the transfer function accuracy.