In this PRISMA image of Lake Trasimeno acquired on November 30, 2020, it is possible to notice some typical characteristics of the lake waters. The greenish colour that predominates throughout the lake is due to the presence of phytoplankton: Lake Trasimeno is in fact a meso-eutrophic lake with chlorophyll concentrations averaging 9 mgm-3. The lighter streaks well visible inside the lake, especially in the western part, represent instead the sediment resuspensions phenomena due to winds and therefore the presence in water of suspended solids, which are manifested by causing an increase in the electromagnetic signal emerging from the water in the wavelengths of Red and NIR (Near-Infrared). The southernmost part of the lake, below the Polvese Island (the largest of the three islands of Lake Trasimeno) has the typical darker colour due to the presence of submerged and floating macrophytes.
The image, that is a crop of a 30x30 km spotlight acquisition, has been elaborated in the framework of the ASI project “Sviluppo di Prodotti Iperspettrali Prototipali Evoluti” whose main objective is the prototyping of a subset of L3 / L4 value-added products to be retrieved by means of hyperspectral data processing. Among the prototypes that are intended to be developed, there is the Water Quality product that reports the following parameters: Phytoplankton, Total Suspended Matter, Bottom Substrate.
Data/Information generated by Federica Braga – Centro Nazionale delle Ricerche-Istituto di Scienze Marine (CNR-ISMAR), Mariano Bresciani and Claudia Giardino – Centro Nazionale delle Ricerche-Istituto per il Rilevamento Elettromagnetico dell’Ambiente-(CNR-IREA), under an ASI License to Use; Original PRISMA Product - © ASI – (2021)