ABSTRACT

Exchange flows in lake-wetland interfaces driven by horizontal gradients of temperature and wind play a relevant role in the transport of nutrients, pollutants and other substances affecting lakes ecology. A field campaign was carried out at Lake Vela (Figueira da Foz, Portugal) to access the impact of wind and horizontal temperature gradients on surface exchange flows. A weather station and four water temperature probes installed in a littoral-pelagic transects are continuously collecting data allowing the characterization of seasonal and diurnal variations. Superficial flow velocity was computed by Particle Tracking Velocimetry (PTV) and Particle Image Velocimetry (PIV) techniques employing images acquired by a drone equipped with a CMOS sensor camera. The results revealed an important role of the wind on the thermally driven exchange flows of vegetated lakes.