Monitoring of Reservoirs by Remote Sensing

The current availability of powerful computer tools and the acquisition by means of satellites of images generated by remote sensors with a high spatial and temporal resolution, allows the monitoring of the trophic state in reservoirs , evaluating the reflectance signals collected by the sensors on board the satellites.

Based on this technology, the Confederación Hidrográfica del Ebro , through the Subdirección General de Protección de las Aguas y Gestión de Riesgos, is carrying out, through service contracts, the monitoring of several reservoirs in the Ebro river basin.

In collaboration with OFITECO and the University of Valencia, LWD has carried out a study on the trophic status of 17 Ebro reservoirs for the year 2020.

The objective of this work has been to obtain a methodology that allows obtaining, in almost real time, water quality maps using reservoirs as reference water masses. To do this, the physicochemical data provided by the Water Quality Area have been combined with the images generated by remote sensors.

The parameters studied are those that have optical properties that can be measured by the satellite. Thus, equations have been calibrated for estimating the concentration of chlorophyll-a, suspended solids, transparency, turbidity, phycocyanin concentration and chromophoric organic matter concentration (CDOM)

Thus, equations have been calibrated to estimate the concentration of chlorophyll-a, suspended solids, transparency, turbidity, phycocyanin concentration and chromophoric organic matter concentration (CDOM). Calibrated equations and quality maps have been obtained for each reservoir studied. In addition, the trophic status of each body of water has been estimated both with the data acquired through the Sentinel-2 and Landsat-8 satellites, and with the data in the field campaigns.

The final report with the results achieved after carrying out the work was delivered in September 2021