The water quality of the Sitjar reservoir investigated through images from the Sentinel-2 satellite
Research personnel from the Image Processing Laboratory, at the University of Valencia Science Park, have studied the water quality of the Sitjar reservoir (Castelló) between April 2017 and March 2019, using fourteen images obtained by the Sentinel 2 satellite (S2). The research, published in Revista de Teledetección, has analysed different biophysical variables such as transparency, chlorophyll-a and total suspended solids, and compares them with the results of field work, to relate these parameters to the weather.
30 de december de 2020
“This work shows the usefulness of the new products offered by the S2 satellite within the Copernicus program of the European Union, an ambitious program for remote sensing and Earth observation with a multitude of applications in different fields. The results obtained show how the S2 images are a useful tool in monitoring water quality and allow information to be periodically obtained from the entire surface of the reservoir”, highlights Cristina Radin, co-author of the work and student of the Doctoral Programme in Remote Sensing of the University of Valencia (UV).
The research, led by the professor of the Department of Earth Physics and Thermodynamics Jesús Delegido, shows a high correlation between these biophysical variables during the analysed period. Thus, in spring, autumn and winter, coinciding with the rainy seasons, the concentration of chlorophyll-a (green pigment produced by phytoplankton) and the total solids in suspension (indicator of turbidity in aquatic ecosystems) is older. On the other hand, in summer the lack of nutrients and rainfall makes the presence of phytoplankton difficult and the concentration of these variables is lower.
The research, in which UV researcher Xavier Sòria-Perpinyà has also participated, shows the importance of studying the water quality of the Sitjar reservoir, which allows mitigating droughts and floods caused by torrential rains – with the consequent increase in the flow of the river Mijares – in order to control irrigation and produce energy. In addition, this reservoir offers a wide range for the tourism sector by providing a recreational environment. The study of the quality of its waters is also important due to its repercussion on human health and the state of the aquatic ecosystem.
The research is part of the ESAQS project (Monitoring of the ecological status of continental waters and coasts of the Valencian Community with the new Earth Observation satellites), financed by the ValencianGovernment through the Prometheus program. Jesús Delegido is a member of the Laboratory for Earth Observation (LEO), which is part of the Image Processing Laboratory, a multidisciplinary research unit of the University of Valencia.
Article: Radin, C., Sòria-Perpinyà, X., Delegido, J. 2020. «Multitemporal water quality study in Sitjar (Castelló, Spain) reservoir using Sentinel-2 images». Revista de Teledetección, 56, 117-130. https://doi.org/10.4995/raet.2020.13864
Attached photo caption:
The Sitjar reservoir, located on the Mijares river.