遥感技术在河口颗粒态总磷分布及扩散研究中的应用初探

Preliminary study of concentration distribution of total particulate phosphorus in estuary by remote sensing technology

以美国SeaStar卫星装载的SeaWiFS海洋水色遥感传感器作为遥感数据源,实测了光谱、海表温度、悬浮物含量、透明度、叶绿素浓度、颗粒态总磷含量等,建立了传感器悬浮物含量和颗粒态总磷含量的遥感信息提取模式,结果表明: (1)利用遥感技术估算的海水悬浮物的平均相对偏差为18 1%; (2)悬浮物在遥感图象上的分布和扩散趋势与实际吻合,并且在一定程度上反映了区域内海流运移路径; (3)颗粒态总磷含量在长江河口和杭州湾附近海域较高,由近岸向远岸迅速降低,与实际分布相符; (4)模型主要适用于河口等悬浮物含量高的Ⅱ类水休,对于以浮游植物为主的Ⅰ类水体应另外建立模式.

The SeaWiFS loaded on SEASTAR is used as remote sensing data source. With the in-situ data of suspended sediment concentration(SSC) and total particulate phosphorus(TPP), and inverse regression equation,which suggests the exponential relationship between in-situ suspended sediment concentration data and in-situ radiance data, is employed: y_(SSC)=0.382 6exp[4.974 8(R_(670)/R_(555))],r^2=0.917 9.Meanwhile the concentration of particulate phospiorus can be obtained by the following algorithm:y_(TPP)=(0.007 6)x_(SSC)+0.159 9,r^2=0.720.So the distributive characteristics of suspended sediments and particulate phosphorus in the Changjiang River Estuary and nearshore were retrived through satelite data. The result suggests that (1)the retrieved concentration distribution accords with the ground trouth, and reflects the actual transport path of ocean current to some extent; (2)the concentration of TPP declines gradually from inshore to offshore; and (3)the algorithm is only applicable for Case Ⅱ water,not for Case Ⅰ water.