Untitled - MendelNet 2013 - Mendelova zemědělská a lesnická ...

MENDELNET 2013development of the coefficient of linear correlation existing between the measured and calculateddistributions of temperatures in the territory of the Czech Republic, see Fig. 3. This picture showsthat for time t=3.04, i.e. for the January 2006, the coefficient of linear correlation is only 0.196although its average value is 0.925. Provided that values for the January 2006 were eliminated fromthis calculation, the values of the average coefficient would increase only to 0.931; this indicatesthat this single value does not influence the quality of the regression function.It is possible to express graphically the distribution of differences between values measured andcalculated for individual meteorological stations in January 2006 – the worst correlation, red points,and compare it with differences of temperatures with the highest coefficient of correlation – May2004; blue points, see Fig. 4. When comparing both pictures, it is possible to see that in January2006 the differences between measured and calculated temperatures were three-times higher than inMay 2004; above all, however, in January 2006.Fig. 3 Trend of the spatial correlation Fig. 4 Temperature differencesAverage annual temperatures and their changes: In case that members containing goniometricfunctions, sinus and cosines, modelling the course of periodical temperature change, are removedfrom the regression function we receive function describing time dependence of the average yeartemperature. This function can be differentiated according to the time (2):T t( x, y,h) = 0.000112 x−0.000450 y−0.000025h− 0.0216583 .(2)The function (2) determines the development of average temperatures in the territory of the CzechRepublic. Its positive values indicate warming, while negative ones inform about cooling. Zeroannual changes correspond with the equation T t (x,y,h)=0, which defines above the territory of theCzech Republic a plane that can be expressed graphically, see Fig. 5. This figure indicates that inthe Czech Republic, the majority of meteorological stations are situated above the planeT t (x,y,h)=0; this means that the annual temperatures are decreasing there in time.Lay-out of decreasing temperatures: In case that values hi = 410, 450, 490 and 1320 [m] aregradually substituted into the equation (2) then this equation will be changed to Tt(x,y,hi)=0, i.e. toequations of lines. Values hi express the average altitudes of Moravia, Czech Republic, Bohemiaand the Lysá hora mountain. Individual lines can be thereafter mapped and drawn into the map ofthe Czech Republic, see Fig. 6. As can be seen, the territory of the Czech Republic situatednorthwards from the line Churáňov–Mošnov is getting cooler while that situated southwards fromthe line Kuchařovice–Strážnice is becoming warmer. Within the zone demarcated by these twolines the course of annual temperatures is dependent on the altitude, i.e. the higher the locality, thelower annual temperatures.344 | P age