Climatological air temperature maps for Poland as the GIS application results

The study presents the air temperature maps and their construction methods with the GIS techniques. It was done for territory of Poland and the neighboring areas covering about 500 km2. Different maps and some diagrams based on the mean and maximum temperature means have been created. Meteorological data originated from 213 stations situated at different altitudes and locations. Most series contain observations from the second half of 20-th century. Some shorter series were reduced to the common 30-years period. It was possible to use those data for so called climatological normals period (1961-1990) as well as for other periods up to 2000. The second type of data concerns geographical parameters. Altitude, latitude, longitude and the distance to the Baltic coast (for stations located closer than 100 km) have been taken into consideration. Statistical analysis confirmed that the terrain feature (elevation) plays the most important role in the temperature field distribution. Determination coefficients between temperature and altitude were very high exceeding 0.92. That parameter was calculated from the digital elevation model with the resolution of 250 m. In the next phase a couple of the spatialization methods have been tested (ordinary kriging, cokriging, universal kriging and residual kriging). The last one has been chosen for the map constructions. So in the first step a multivariate linear regression has been applied, than the residuals of regression model were calculated for each station location and finally interpolated by ordinary kriging method. In this manor different climatic maps e.g. with mean annual and seasonal temperature as well as with different other thermic characteristics have been created. Thanks to GIS techniques the calculation of some other climatic indices was possible (e.g. calculation of the area with the specific parameters). Finally some mean daily data for the unusual thermic events have been used. Estimation of the applied method gives rather very positive results. Comparison between measured/observed values and predicted/calculated ones are usually less than 0.2°C. The test was done for the 7 elements sample of independent data. In the next step the application of the minimum temperature values is being planned. However, for smaller areas where some microclimatic differentiation is being observed some additional geographical parameters should be used e.g. type of geomorphic forms, slope aspects etc.