基于GF1_WFV的千岛湖水体叶绿素a浓度时空变化

基于高分一号（GF-1）遥感影像以及水体实测样点数据，运用波段对数组合，以千岛湖为研究对象，构建和择优了叶绿素a浓度反演模型，对2013~2019年千岛湖区域水体叶绿素a浓度值进行了估算，并利用变异系数、Mann-Kendall显著性检验模型、Theil-Sen趋势分析模型对其时空变化特征进行了分析.研究表明，基于波段对数组合的反演模型可用于千岛湖清洁水体叶绿素a浓度值的反演（R²=0.8976）；年际变化分析发现，在研究期限内，千岛湖水体叶绿素a浓度平均值维持在较低水平，近94%的水体像元叶绿素a浓度小于3.65μg/L，水质较佳；时空动态分析进一步发现，千岛湖水体叶绿素a浓度值大都经历了较为微小的波动变化，其中，有超过67%的水体像元浓度值呈现出微小的增长趋势，在分布上也呈现出一定的空间格局形态.

Spatial-temporal variations of chlorophyll-a in Qiandao lake using GF1_WFV data

We established a simulating model based on the GF-1spectral reflectance features and field survey results. The model was then applied to estimate the concentration and distribution of chlorophyll-a in Qiandao lake from 2013~2019. Our model could effectively estimate the chlorophyll-a concentration in clean water (R²=0.8976). Pixel level analysis revealed that over 94% of water pixels contained less than 3.65μg/L of chlorophyll-a, indicating that the chlorophyll-a concentration of Qiandao lake was quite low during the study period. Moreover, the spatial-temporal analysis showed that the chlorophyll-a concentration in most water pixels experienced a small variation. More than 67% water regions had a slight increase.