Flood frequency characterization of the Nhecolândia region (Pantanal) based on high spatial and temporal resolution PlanetScope satellite images

Abstract

The study of aquatic systems is becoming increasingly critical due to global concerns about sustainable water resource management. This research examines the dynamic inundation frequency of the Nhecolândia region, one of the Pantanal’s most famous landscapes, using high-resolution time-series images from PlanetScope nanosatellites processed on the Google Earth Engine (GEE) platform. The region consists of a complex wetland with a mosaic of saline and freshwater lakes, as well as intermittently flooded water channels. The results reveal seasonal fluctuations in water surfaces across three pilot areas, highlighting substantial changes during flood events. Notably, Area 1 experienced a 16.7% increase in the water surface area at peak flooding, while Areas 2 and 3 recorded increases of 24.3% and 33.5%, respectively. These changes significantly alter the landscape, as freshwater lakes overflow and merge into a single feature along the water channels. The analysis indicates asynchronous flooding dynamics among the areas, driven by local precipitation and evaporation rates, along with the region’s low topographic gradient. Additionally, this study underscores the advantages of nanosatellite imagery, demonstrating spatial and temporal information gain over traditional satellite systems, enabling detailed mapping of seasonal floods and small water features. The outcomes include flood frequency maps, water surface area evolution charts, and RGB visualizations of spatiotemporal flood patterns. These products represent the first high-resolution systematic record of seasonal flooding for the studied areas. The findings contribute to understanding the hydrological behavior of the Nhecolândia region, providing a scientific foundation for further research and management strategies in vulnerable wetland ecosystems.