基于GF6-WFV数据的中国东部典型湖库叶绿素a浓度反演

Chlorophyll-a Concentration Inversion based on GF6-WFV Data in a Typical Lake Reservoir in Eastern China

高分六号中分辨率宽幅相机(GF6-WFV)设计了两个红边波段,具有水体叶绿素a浓度监测的潜力。实验选取官厅水库、陆浑水库和白洋淀等6个中国东部典型湖库为研究区,获取141个采样点实测光谱和叶绿素a浓度数据。基于实测数据对4种常用的叶绿素a浓度反演半经验模型进行参数优化和模型精度验证,选取最优反演模型。结果表明,GF6-WFV数据新增红边Ⅰ波段(B5:710 nm)和红波段(B3:660 nm)构建的两波段比值模型反演精度较高,相关系数平方(R^(2))为0.89,平均相对误差(MRE)为34.71%,均方根误差(RMSE)为13.29 mg/m^(3)。研究表明:利用GF6-WFV影像数据能有效反演水体叶绿素a浓度,研究基于多湖库、多时相数据建立的GF6-WFV影像水体叶绿素a浓度反演模型,在中国东部典型湖库具有较好的适用性。

The Gaofen-6 medium resolution wide-width camera(GF6-WFV)is designed with two red-edge bands,which has the potential to monitor chlorophyll a concentration in water.In this study,six typical lakes in eastern China,including Guanting Reservoir,Luhun Reservoir and Baiyangdian Lake,were selected as the study area,and measured spectrum and chlorophyll a concentration data were obtained from 141 sampling points.Based on the measured data,the parameters of four kinds of commonly used semi-empirical inversion models of chlorophyll a concentration were optimized and the model accuracy verified,and the optimal inversion model was selected.The results show that the red edge bandⅠ(B5:710 nm)and red band(B3:660 nm)are newly added in GF6-WFV data.Which construct a two-band ratio 2BDA model with high inversion accuracy,correlation coefficient square(R^(2))is 0.89,the Mean Relative Error(MRE)is 34.71%,and the Root Mean Square Error(RMSE)is 13.29 mg/m^(3).The results show that the chlorophyll a concentration in water body can be effectively retrieved by using GF6-WFV image data.The inversion model of chlorophyll a concentration in water body established in this paper based on multi-lake and multi-temporal data has good applicability in typi-cal lake repositories in eastern China.