Infrared Remote Sensing for Quantifying River Thermal Heterogeneities and sensors comparison

Abstract

Water temperature is a key parameter in aquatic ecosystems controlling chemical and physical processes. These essential ecosystems have been threatened for many years by increasing anthropogenic pressure and worrying climate change. Existing data of water temperature are generally derived from thermometers which, although accurate, have very low spatial resolution. Fortunately, the development of new technologies has made it possible to apply new methods of temperature measurement such as remote sensing by infrared thermography. The high spatial resolution offered by this technology allows to study thermal heterogeneities and consequently to learn more about the functioning of watercourses by determining factors influencing its temperature. Therefore, the objectives of this work consisted rstly in using a method of remote sensing by infrared thermography to highlight the spatial thermal variability of water in the environment of a river. Secondly, to compare the results from two different thermal cameras, and nally to compare the measurements from infrared thermography with a classical in situ temperature measurement by thermometers.