基于GF-1/WFV的钱塘江叶绿素a和总悬浮物浓度遥感估算

为了探究高分一号(GF-1)卫星对河流水体水质参数遥感反演的效果,使用GF-1卫星数据的16 m分辨率的GF-1/WFV传感器数据和地面实测数据,基于地面实测光谱反射率数据模拟WFV波段组合,构建水体叶绿素a和总悬浮物浓度遥感模型,从而对钱塘江流域杭州段水体水质参数进行估算。研究结果表明:基于B1-B3差值的二次多项式模型可用于叶绿素a浓度估算(R²=0.83,RMSE=0.74 μg/L),基于B3波段的二次多项式模型可用于总悬浮物浓度的估算(R²=0.92,RMSE=1 mg/L);通过模型应用于准同步的GF-1/WFV数据,较好反映了低潮位钱塘江杭州段水体叶绿素a和总悬浮物浓度的空间分布,为高分一号卫星数据遥感监测钱塘江水色参数做出了有益的探索性工作。研究方法及结果对其他流域河流水色遥感研究具有参考价值。

Remote Sensing Estimation of Chlorophyll-a and Total Suspended Matter Concentration in Qiantang River Based on GF-1/WFV Data

In an attempt to explore the effect of Gaofen-1 (GF-1) satellite on remote sensing inversion of river water quality, the remote sensing estimation models of Chlorophyll-a and total suspended matter concentration were constructed to estimate the water quality in Hangzhou segment of Qiantang River by simulating the WFV bands by in situ spectral reflectance based on the GF-1/WFV data with 16 m resolution and the ground measured data. Results prove that the quadratic polynomial model based on the reflectance difference of B1 and B3 band (B1-B3) can be used to estimate the Chlorophyll-a concentration with R²=0.83 and RMSE=0.74 μg/L; the quadratic polynomial model based on the B3 band reflectance can be used to estimate the total suspended matter concentration with R²=0.92 and RMSE=1 mg/L. The models were applied to quasi-synchronous GF-1/WFV data, which well reflected the spatial distribution of Chlorophyll-a and total suspended matter concentration in the low-tidal Qiantang River. This research is a useful exploratory work to monitor the water color parameters of Qiantang River by the GF-1 satellite data, and the research methods and results offer reference for the study of water color remote sensing in other river basins.