A multi-sensor framework in Google Earth Engine for trend analysis of water quality parameters in Anzali lagoon

Abstract Monitoring of water quality parameters (WQP) in Anzali Lagoon is deemed a priority for protection and prevention of its degradation. The current study investigates the environmental condition of the wetland between 2014 to 2021 using remote sensing technology. A multi-sensor framework was developed in google earth engine for spatio-temporal trend analysis of water quality parameters in Anzali lagoon. The spatial distributions indicated that the critical points of the lagoon are changing from the Western to the center and Eastern parts. The comparison of the WQP parameters with the environmental standards confirmed that the lagoon condition is in critical stage, especially in terms of TSS. Nitrate values showed that 50% of the lagoon area exceeds the environmental standards, which indicates the nutritional status. The investigated WQP has had a significant positive trend in most areas, so the lagoon is under high environmental risk and unfriendly human activities should be controlled.