## 3 Results and Discussion
### Temperature Field of the Dam  
Based on the results of the 2D thermal analyses of the complete dam for the one year period, the temperature fields of the dam during the year were defined, using time periods of two months, starting from 1 October 2013 at 12:00. The temperature fields were plotted using the computer program DIANA [49], where an identical model of the dam as in MATLAB was constructed (i.e., it had the same arrangement and the same denotation of finite elements and nodes), so that when making the temperature fields in DIANA, the results of the thermal analyses calculations from MATLAB (the nodal temperatures at the selected times) were used. Comparing the calculated temperature fields, it was found that the largest gradients in the concrete temperature were recorded in the area close to the surface of the insolated upper part of the downstream side of the dam (Figure 14). This was in summer, when the highest air temperatures occurred and when not much shade was recorded on the downstream side of the dam. For determining the temperature gradient by depth, the two typical cross-sections, A-A and C-C, were chosen (Figures 2 and 14). The four selected points (nodes) coincided with the locations of the temperature gauges.  
Figure 14: The calculated temperature field of the Moste Dam (1 August 2014 at 12:00).  
The concrete temperatures at the two characteristic cross sections in summer (1 August 2014 at 12:00) and in winter (1 February 2014 at 12:00) are presented in Figure 15. It can be seen from this figure that in cross-section A-A at the downstream insolated side of the dam in the summer the calculated temperature from the concrete surface to a depth of 0.2 m was reduced by 9.8 \({}^{\circ}\)C, whereas it was reduced at a depth of 1.0 m by 2.4 \({}^{\circ}\)C, and by an additional 2.0 \({}^{\circ}\)C at a depth of 2.0 m. This suggests that the temperature gradient is largest in a very narrow area along the surface of the concrete. The calculated concrete temperatures in cross-section A-A also indicate that the temperature stabilizes at a depth of about 6.0 m. In the analyzed case, in winter the temperature gradient of the calculated temperatures close to the surface was much smaller, but the strong effect of temperature can be observed up to a depth of 2.0 m. Both in summer and in winter the measured values at three points (at depths of 0.2, 0.5 and 1.0 m) were somewhat higher (by 1.3 to 2.5 \({}^{\circ}\)C) than the calculated values.  
In cross-section C-C at the upstream side in the summer, when the water level of the reservoir was above the analyzed cross-section, the calculated temperatures from the concrete surface to a depth of 0.3 m were reduced by 2.4 \({}^{\circ}\)C, whereas up to a depth of 1.4 m they were reduced by an additional 1.7 \({}^{\circ}\)C. This suggests that the temperature gradient is the greatest up to a depth of 0.3 m, and is significantly lower in comparison with the analyzed case in winter (the temperature gradient up to a depth of 0.3 m was 5.8 \({}^{\circ}\)C) when the water level of the reservoir was below the analyzed cross-section, so that the concrete surface was exposed to the air. Both in summer and in winter the measured value at a depth of 0.3 m matched the calculated values very well (the differences were 0.1 \({}^{\circ}\)C and 0.6 \({}^{\circ}\)C, respectively).