应用遥感技术手段监测珠江口水质环境的变化。根据Landsat卫星在最近25年间的图像信息，显示出珠江口与香港周围海域浑浊水域不断扩大的趋势，揭示多种因素叠加带来海洋环境恶化的深层原因。研究方法上提出了在邻近海岸带的浑浊和较浅的二类水体中存在“多次散射”的概念，应用海洋遥感研究成果“斜率法”进行标定，并尝试应用“对比”的方法探讨二类水体的图像处理方法。

Pearl River Estuary is an important region for South China, including Hong Kong and Macao. It has experienced tremendous environmental changes due to the fast social and economic development in Pearl River delta, especially in recent decade. It is rather difficult to realize the changes of water quality for this large complex estuary system over a long period by the traditional measurements. Remote sensing technology is used to monitor the evolution of marine water quality. The historic Landsat data over twenty-five years are applied to extract the changing information of ocean color. The results show an alarming fast trend of high turbid waters in Pearl River Estuary and Hong Kong coastal waters in these years. The algorithm of "Gradient Transition" is used to calibrate the resulting images to give quantitative analysis of turbid waters. Reasons for such deterioration are discussed in detail. A comparson method is proposed to process and analyze Landsat images to get feature of ocean color of Case 2 waters. The concept of multiple scatters is suggested for the study of turbid and shoal Case 2 waters near coastal zone.