Method of monitoring surface water quality based on remote sensing in Miyun reservoir

Excessive growth of algae can be considered as a symptom of eutrophication, which is caused by overloading nutrients and results in significant daily dissolved oxygen variation and even an unbalanced ecosystem. It is very important to monitor the surface water quality and track their changes. The objective of this study is to monitor the surface water quality of Miyun reservoir using remote sensing method based on the empirical correlation between the water quality parameters and band combinations of image. It is discovered that the band 3 and 4 are very important, and the ratio of band 4 to 3 is well relative with chlorophyll-a concentration, and a combination of band 2, 3 and 4 is well relative with total nitrogen concentration. Then the empirical correlation model is applied to the whole surface water of Miyun reservoir. As a result, the chlorophyll-a concentration and total nitrogen concentration decrease from the northeast to southwest, clearly illustrating the eutrophication state of Miyun reservoir. The study proved that the remote sensing monitoring method with a large-scale, dynamic and low-cost advantage is very potential for monitoring lake surface water quality.