Estimation of the eddy thermal conductivity for lake Botonega


  • Danila Lozzi-Kožar Croatian Waters
  • Ivica Kožar University of Rijeka Faculty of Civil Engineering


thermal lake model, stratification, inverse model, finite element method


This paper presents a part of a computer modelthat is suitable for limited temperature predictionand its application for Lake Botonega, which islocated in Istria, Croatia. The main assumption ofthis study is that the heat transfer can be describedby the eddy diffusivity model to formulate themodel of the heating and cooling of a lake using aseries of water and air temperature measurements.The coefficient of thermal diffusion, which is afunction of the lake depth, is determined using theinverse model of eddy thermal diffusivity. Theinverse model is linearized using the finite elementapproach. The model of lake thermal diffusivityconsists of a conductive part and a radiative part,with the latter part being replaced with the heatflux on the boundary. The model parameters arecalculated in two steps—a predictor step and acorrector step—and the coefficient of conduction iscalculated instead of the diffusion.The estimated parameters are intended forinclusion in a simple three-dimensional thermalmodel, which provides the lake temperatureprediction that is based on previous temperaturemeasurements, as demonstrated in the examples.

Author Biographies

Danila Lozzi-Kožar, Croatian Waters

VGO RijekaIndependant Engineer

Ivica Kožar, University of Rijeka Faculty of Civil Engineering

University of Rijeka Faculty of Civil Engineering