Satellite images were used to assess surface water quality based on the concentration of chlorophyll a (chla), light penetration measured by the Secchi disk method (SD), and the Cyanobacteria cells number per mL (cyano). For this case study, six reservoirs interconnected were evaluated, comprising the Cantareira System (CS) in São Paulo State (Brazil). The work employed Sentinel-2 images from 2015 to 2018, SNAP image processing software, and the native products conc_chl and kd_z90max, treated using Case 2 Regional Coast Color (C2RCC) atmospheric correction. The database was obtained from CETESB, the agency legally responsible for operation of the Inland Water Quality Monitoring Network in São Paulo State. The results demonstrated robustness in the estimates of chla (RMSE = 3.73; NRMSE% = 19%) and SD (RMSE = 2,26; NRMSE% = 14%). Due to the strong relationship between cyano and chla (r² = 0.84, p < 0.01, n = 90), both obtained from field measurements, there was also robustness in cyano estimates based on the estimates of chla from the satellite images. The data revealed a clear pattern, with the upstream reservoirs being more eutrophic, compared to those downstream. There were evident concerns, about water quality, particularly due to the high numbers of Cyanobacteria cells, especially in the upstream reservoirs.

卫星图像用于根据叶绿素a（chla）的浓度，通过Secchi圆盘法（SD）测量的光渗透率和每毫升蓝细菌细胞数（氰基）评估地表水质量。在此案例研究中，对六个相互连通的储层进行了评估，包括圣保罗州（巴西）的坎塔雷拉系统（CS）。该工作采用了2015年至2018年的Sentinel-2图像，SNAP图像处理软件以及本机产品conc_chl和kd_z90max，并使用Case 2 Regional Coast Color（C2RCC）大气校正技术对其进行了处理。该数据库是从CETESB获得的，CETESB是负责圣保罗州内陆水质监测网络合法运营的机构。结果证明了chla（RMSE = 3.73; NRMSE％= 19％）和SD（RMSE = 2,26; NRMSE％= 14％）估计值的鲁棒性。r ² = 0.84，p <0.01，n = 90），两者都是通过现场测量获得的，基于卫星图像中chla的估计值，氰基估计值也具有鲁棒性。数据显示出一种清晰的模式，与下游的相比，上游的水库富营养化。人们对水的质量存在明显的担忧，特别是由于蓝细菌细胞数量众多，尤其是在上游水库中。