Developing a thermodynamic a conceptual model for the Itumbiara hydroelectric reservoir based on satellite and telemetric data

Abstract

Aquatic systems continually respond to climatic conditions that vary over broad scales of space and time. The response of each water body to external conditions (hydro-meteorological processes) is revealed in the first place by the thermal structures present in water body. Most lacustrine chemical, physical and biological processes are affected directly by lake hydrological (e.g. lake depth) and thermal changes (e.g. seasonal stratification), and are thus, indirectly affected by climate variation. Understanding lake-climate system interactions is therefore of fundamental importance to evaluate the effects of climate change on limnological processes. Based on this, the objective of this work was to develop a thermodynamic conceptual model for the Itumbiara hydroelectric reservoir (Goiás State, Brazil). The developed methodology was based on the use of satellite imagery of moderate resolution that allow the computation of the water surface temperature from 2003 to 2008 (six years) during the daytime and nighttime. The results showed the potential of the use of moderate resolution satellite data to study water surface temperature variability and to explain the main causes of this variability. The use of hydro-meteorological and bulk temperature collected by station and autonomous buoy, respectively, contributed to better understand the physical processes in the mixed depth of the reservoir. Also the results allow the elaboration of conceptual models for the thermodynamics of the Itumbiara reservoir.

Keywords

• heat flux
• temperature
• MODIS/Terra
• stratification and mixing