我国湖泊富营养化问题严重，藻华暴发频繁，藻颗粒含量丰富。基于自身光合作用的需要和外界环境条件的影响，这些藻颗粒或富集于水面或堙没于水体，引起水面介质改变和水体垂向分层。水面介质的改变，引起水－气界面特性发生变化，进而改变了进入水体的光场结构；藻颗粒垂向分层，改变了水体光学辐射传输的方向和路径，基于均质水体假设的传统水色遥感理论受到挑战。本课题以太湖为研究试验区，引入“单元水柱”的概念，以室内外试验观测和辐射传输数值模拟为主要手段，以蓝藻颗粒及其聚集体的固有光学特性研究为出发点，分析水面藻颗粒密度对恰在水面以下光场的影响，耦合藻颗粒垂向分布函数，构建水下光场精确分布模型，探索像元尺度的遥感反射比对单元水柱水面藻颗粒密度的响应关系，研究水体藻颗粒空间分布不均匀对遥感反射比的影响机理。该研究可为富营养化湖泊藻类生物总量的遥感估算提供基础和依据，并可丰富和发展湖泊等II类水体水色遥感的理论与方法。

Lake water eutrophication is becoming a serious issue in China. It leads to frequent occurrence of algal blooming and high content of algal particles. Algal particle can adjust the position itself in the water and changes the substance composition of water surface and the vertical stratification of water body. This former change causes the variation of air-water interface properties, thus affects the angle and intensity of light when entering into the water surface; the latter changes the routes and directions of optical radiation transfer in waters, which has brought a big challenge to the tradition theory and methods based on homogeneous water body of water color remote sensing. In this project, we take Lake Taihu as the study area and propose the concept of "unit water column". It depends on researches on the IOPs of algal particles and congeries, analyses the influence of algal particles that floating on the water on the light field under water surface and couples the vertical distribution functions of algal particles with the main methods of experiment observation indoor/outdoor and radiation transfer simulation, aims at establishing distribution model of underwater light field more accurately. We explore the response relationship between remote sensing.reflectance at pixel scale and the density of algal particles in different units of water column and study the influence mechanism that algae particles on remote sensing reflectance. This project may provide scientific evidence for remote sensing estimation on algal biomass in eutrophication lakes and enriches the remote sensing theory and method of case II waters..