Climate change in Hungary during the twentieth century according to Feddema

Climate change in Hungary during the twentieth century is analyzed using Feddema's original scheme suitable for global scale applications (F-GS) and Feddema's fine-tuned scheme designed for Hungarian applications (F-HU). Input data of precipitation (P) and air temperature (T) are taken from the Climatic Research Unit (CRU) TS 1.2 database constructing P-T data referring to three 30-year periods (1901-1930, 1941-1970, 1971-2000) and two 50-year periods (1901-1950, 1951-2000). The method and data organizational effects are compared using these schemes and data sets. The results show that the evaluation of the climate change process depends much more on the methodological rather than on data organizational effects. Methodical fine-tuning effects considerably improved the spatial distribution, while the organization of data improved the insight into the dynamic of the processes. According to F-GS, there is no climate change on 76.7 % of Hungarian territory. According to F-HU, such areas amount to only 38.5 %. The main climate change process for F-GS is drying, while for F-HU drying and warming beside either drying or warming. For both models, the most climate change affected areas are characterized by higher altitudes, such as in the Mecsek and Villany Mountains (geographical region Transdanubia), in the Bukk Mountains (geographical region North Hungarian Mountains), and in the region of the so-called Danube Bend. The spatially most realistic climate description is obtained by using F-HU and the 30-year data sets. It is to be noted that Koppen's, Holdridge's, and Thornthwaite's methods are less suitable than F-HU for representing the process of climate change in Hungary in the twentieth century.