Challenges and Advances of Inland Waters Monitoring: A Case Study Highlighting the Use of Satellite Imagery and Cloud Computing in Brazil

Monitoring of the quality of inland waters is important to maintain the aquatic ecosystems health and to ensure water quality standards established by environmental laws in each country. Our goal here is to present the possibilities and challenges of water quality mapping based on Sentinel 2 and Landsat 8 satellite images in geographically distinct Brazilian reservoirs as a study case. The satellite images were able to show chlorophyll a, turbidity, and Secchi data trends over 8 years of remote sensing monitoring. The time savings in the analysis of a large dataset and the availability to a wide range of stakeholders make remote sensing a good tool for monitoring inland waters. However, water quality parameters were highly influenced by cloud cover and the accuracy was low at the margin of tributary rivers. The integration of remote sensing and in situ data are needed to increase the effectiveness and accuracy of the remote sensing tools.