Assessing hydrological dynamics of Guyana's North Rupununi wetlands using Sentinel-1 SAR imagery change detection analysis on Google Earth Engine

Abstract

Wetlands are among the most productive natural ecosystems in the world, generally being important biodiversity hotspots. However, the complex nature of these landscapes together with the fragile and dynamic relationships among the organisms inhabiting these regions, make wetland ecosystems especially vulnerable to environmental disturbance, such as climate change. Thus, developing new automated systems which allow the continuous monitoring and mapping of wetland dynamics is crucial for informing decision-making and preserving their natural health. Synthetic Aperture Radar (SAR) sensors deployed on satellite platforms such as SENTINEL-1 are increasingly recognized as essential for wetland monitoring. The high sensitivity of SAR sensors to environmental variation makes them particularly suitable for investigating the hydrological processes occurring within these ecosystems. The main objective of this paper is to propose a rapid polarimetric SAR (PolSAR) change detection tool for monitoring and mapping the flood dynamics and environmental condition of the North Rupununi region, Guyana. By making use of dense Sentinel-1 timeseries data and the Google Earth Engine (GEE) platform, we were able to map temporal open water and temporal flooded vegetation areas in a continuous and near-real time basis. The outcomes derived from this study significantly contributed to identify the hydrological mechanisms of the region of study while providing essential and valuable information for rapid response and environmental impact assessment.