Identification of Emergent and Floating Aquatic Vegetation Using an Unsupervised Thresholding Approach: A Case Study of the Dniester Delta in Ukraine

Monitoring of emergent and floating vegetation in freshwater ecosystems is of high importance for water management in an area. This study proposes a methodology for the automatic monitoring of aquatic vegetation using indicators estimated via remote sensing image analysis. The study area is located in the Lower Dniester Basin in Southern Ukraine. The approach is developed using Sentinel-2 images and validated with field measurements. The goal is to discriminate and map three classes of aquatic surface condition; namely, areas covered with floating vegetation, or dominated by emergent vegetation, and open water. The approach is transferable across different dates over a period of three years. Results are useful for governmental authorities and natural/ national park administrations for near real-time monitoring of aquatic vegetation to mitigate the impact of overgrowth on water quality, biodiversity, and ecosystem services.