中文摘要：

悬浮泥沙的粒径分布特征不仅体现了悬浮颗粒态物质的存在状态,而且可以指示水动力及再悬浮作用的过程和强度,因此研究悬浮泥沙粒径分布特征具有重要意义。利用Mie理论建立悬浮泥沙平均粒径反演模型,结果表明,悬浮泥沙后向散射系数与其平均粒径的三次方线性关系明显,4个波段（412nm、443nm、555nm、667nm）拟合方程决定系数均在0.93以上,拟合误差最小值为16.6322%（412nm）,最大值为20.3143%（667nm）。利用QAA算法从MODIS影像上反演研究区域悬浮泥沙后向散射系数,并结合反演的悬浮泥沙浓度推算研究区域表层悬浮泥沙的平均粒径。对比发现,近岸高悬浮泥沙区域的反演结果与实测数据吻合较好,相关研究可以为深入开展陆海相互作用、海洋生态系统演变和海洋参与全球碳循环等研究提供重要数据支持。

英文摘要：

Suspended sediment particle size distribution characteristics not only represent the state of being of the suspended particle, but can also be used to imply the procedure and strength of the hydro- dynamics and re-suspension. Mie theory is used to build the suspended sediment average grain size re- trieval model. Results show that suspended sediment backscattering coefficient and the cube of aver- age grain size has ideal linear relationship, with the determination coefficients of the fitting equations all above 0.93 at four bands （412 nm, 443 nm, 555 nm, 667 nm）. The maximal and minimal fitting errors are 16. 632 2~ （412 nm） and 20. 314 3~ （667 nm）, respectively. The suspended sediment backscattering coefficient in the study area was estimated using the quasi-analytical algorithm （QAA） from a MODIS remote sensing reflectance image. Surface water average grain size was estimated by combining the retrieval values of the suspended sediment concentration and the suspended sediment backscattering coefficient. The result shows that values estimated from the inversion model are in good agreement with experimental data from near-shore areas with high suspended sediment content. This study can provide significant supporting data for deep research on land-ocean interaction, marine ecological system evolution, and marine participates in the global carbon cycle.