Prediction of chlorophyll a concentration using HJ-1 satellite imagery for Xiangxi Bay in Three Gorges Reservoir

Since the impoundment of the Three Gorges Reservoir in 2003,algal blooms have frequently been observed in it.The chlorophyll a concentration is an important parameter for evaluating algal blooms.In this study,the chlorophyll a concentration in Xiangxi Bay,in the Three Gorges Reservoir,was predicted using HJ-1 satellite imagery.Several models were established based on a correlation analysis between in situ measurements of the chlorophyll a concentration and the values obtained from satellite images of the study area from January 2010 to December 2011.Chlorophyll a concentrations in Xiangxi Bay were predicted based on the established models.The results show that the maximum correlation is between the reflectance of the band combination of B4/(B2+B3) and in situ measurements of chlorophyll a concentration.The root mean square errors of the predicted values using the linear and quadratic models are 18.49 mg/m3 and 18.52 mg/m3,respectively,and the average relative errors are 37.79% and 36.79%,respectively.The results provide a reference for water bloom prediction in typical tributaries of the Three Gorges Reservoir and contribute to large-scale remote sensing monitoring and water quality management.