Dynamic Monitoring of Lake Based on HJ-CCD Images: A Case Study of Poyang Lake

Lake ecological environment is changing, driving by natural and human factors, and in turn influence people's living and producing. Therefore, dynamic monitoring of lake based on remote sensing technologies will play an important role to the disaster prevention and reduction work of lakes. In this paper, we expounded a series of work to realized monitor Poyang Lake dynamically by using HJ-CCD images. First, we did pretreatment to all HJ-CCD images, which mainly contain geometric correction, atmospheric correlation, image clipping, etc. Then, based on different features between water and non-water in different index layers, we extracted the covered area by water in different times from the corresponding HJ-CCD images, and we also extracted the true area through visual interpretation method. After that, by combining the water boundaries and DEM, we also estimated water level and water capacity in different times. Results of our work showed that the mean absolute error of water area extracted through remote technologies is 5.57%. The relationship of remote sensing areas and visual interpretation areas could be described as S-true = 0.8757*S-interp + 110.24, with R-2 = 0.9807. Besides, there was obvious relationship between water area and water capacity of Poyang Lake too, and the relations can be described with linear function. Based on such results, we can realize the dynamic estimation of Poyang Lake's area and capacity from daily gotten HJ-CCD image which covers the District of Poyang Lake. In other words, the results of this paper can provide decision basis for Poyang Lake's real-time, dynamic, economic monitoring.