渤海悬浮物分布的遥感研究

利用渤海湾和莱州湾现场实测的悬浮物含量和光谱数据,建立了基于555和670nm波段遥感反射率的悬浮物含量遥感反演模型。经检验,模型平均相对误差优于20%,对输入端误差不敏感。基于该模型,利用ENVISAT MERIS遥感数据,从空间分布格局、大风过程的短期扰动以及季节性差异等方面分析了渤海悬浮物的时空分布特征。(1)渤海悬浮物含量的高值区集中分布在莱州湾(尤其是黄河口和莱州湾湾底)和渤海湾沿岸,此外在辽东湾沿岸海域悬浮物含量也相对较高,而在渤海大部水体悬浮物含量较低。(2)大风过程可在短期内(约1~3d)显著改变全渤海的悬浮物空间分布格局,其中渤海湾和莱州湾响应最为强烈,辽东湾响应相对较弱,这与其各自的水深条件、底质类型和悬浮物粒径等因素有关。(3)渤海悬浮物含量总体上呈春夏低、秋冬高的分布特征;季节性差异最显著的区域是渤海湾、莱州湾和辽东湾,差异性最小的是秦皇岛近岸海域;风力等气候因素是悬浮物分布呈现季节性差异的主要原因,入海径流是另一重要因素。

The study on the distribution of suspended particulate matter in the Bohai Sea by remote sensing

The statistical retrieval model for the content of suspended particulate matter (SPM) is developed based on the in situ measurements of SPM content and remote sensing reflectance spectra in the Bohai Gulf and the Laizhou Bay of the Bohai Sea in China The model utilizes spectral information of bands at 555 and 670 nm and is proved to be insensitive to the input noise when bejing applied to the independent dataset The spatio-temporal distribution characteristics of SPM in the Bohai Sea are analyzed in terms of the spatial pattern,the disturbance by sustaining strong wind and the seasonal variability (1) The area with the highest content of SPM in the Bohai Sea is located in the Laizhou Bay and the coastal part of the Bohai Gulf The SPM content is also relatively high in the coastal part of the Liaodong Gulf.The other parts of the Bohai Sea are characterized by the low content of SPM (2) Weather process of sustaining strong wind can significantly alter the SPM spatial pattern in the Bohai Sea in short period (several days) The local responses in the Bohai Gulf and the Laizhou Bay are intense and those in the Liaodong Gulf are weak,which can be explained by the local water depths,different types of bottom and particle size distributions of SPM content in these areas (3) The seasonal feature of SPM distribution in the Bohai Sea is characterized by the high values in autumn and winter and low values in spring and summer The Bohai Gulf is an area with the most significant seasonal variation,whereas the north-west part of the central Bohai Sea near Qinghuangdao is an area with the least.The seasonal variation of SPM content distribution could be attributed to the climate factors such as wind Besides,river runoff is another key factor.