This study investigates the best available methods for remote monitoring inland small-scale waterbodies, using remote sensing data from both Landsat-8 and Sentinel-2 satellites, utilizing a handheld hyperspectral device for ground truthing. Monitoring was conducted to evaluate water quality indicators: chlorophyll-a (Chl-a), colored dissolved organic matter (CDOM), and turbidity. Ground truthing was performed to select the most suitable atmospheric correction technique (ACT). Several ACT have been tested: dark spectrum fitting (DSF), dark object subtraction (DOS), atmospheric and topographic correction (ATCOR), and exponential extrapolation (EXP). Classical sampling was conducted first; then, the resulting concentrations were compared to those obtained using remote sensing analysis by the above-mentioned ACT. This research revealed that DOS and DSF achieved the best performance (an advantage ranging between 29% and 47%). Further, we demonstrated the appropriateness of the use of Sentinel-2 red and vegetation red edge reciprocal bands 1 / B 4 × B 6 for estimating Chl-a ( R 2 = 0.82 , RMSE = 14.52   mg / m 3 ). As for Landsat-8, red to near-infrared ratio ( B 4 / B 5 ) produced the best performing model ( R 2 = 0.71 , RMSE = 39.88   mg / m 3 ), but it did not perform as well as Sentinel-2. Regarding turbidity, the best model ( R 2 = 0.85 , RMSE = 0.87 NTU) obtained by Sentinel-2 utilized a single band (B4), while the best model (with R 2 = 0.64 , RMSE = 0.90 NTU) using Landsat-8 was performed by applying two bands ( B 1 / B 3 ). Mapping the water quality parameters using the best performance biooptical model showed the significant effect of the adjacent land on the boundary pixels compared to pixels of deeper water.

This work addresses the potential impact on water quality and quantifies the benefit of the low carbon power source of floating solar panels in evaporation reduction when using them on an open water body, such as an agricultural irrigation pond in semi-arid regions. By utilizing agricultural ponds for low carbon energy conversion, and saving precious water through evaporation reduction, the highly vulnerable agricultural sector will be empowered. A pilot size setup is prepared, key water quality parameters were monitored and evaporation quantities in a PV-covered pond are compared to those from an adjacent open water pond used as a control. Several inclination angles for the panels were tested. Results showed no adverse impact on the water quality; on the contrary, there is evidence of improvement particularly in nitrate and chlorophyll concentrations. Moreover, a reduction of ~60% in evaporation was observed; power generation from the floating panels, on the other hand, was statistically similar to that from ground-mounted panels.

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This work suggests a solution for preventing/eliminating the predicted Sea Level Rise (SLR) by seawater desalination and storage through a large number of desalination plants distributed worldwide; it also comprises that the desalinated seawater can resolve the global water scarcity by complete coverage for global water demand. Sea level rise can be prevented by desalinating the additional water accumulated into oceans annually for human consumption, while the excess amount of water can be stored in dams and lakes. It is predicted that SLR can be prevented by desalination plants. The chosen desalination plants for the study were Multi-Effect Desalination (MED) and Reverse Osmosis (RO) plants that are powered by renewable energy using wind and solar technologies. It is observed that the two main goals of the study are fulfilled when preventing an SLR between 1.0 m and 1.3 m by 2100 through seawater desalination, as the amount of desalinated water within that range can cover the global water demand while being economically viable.

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