Vízügyi Közlemények, 1936 (18. évfolyam)

Kivonatok, mellékletek - Kivonat a 2. számhoz

19 at 2 o'clock p. m. at the Turkeve station, the summer (Table III and IV/b) and the annual mean values of the relative moisture (Table IV/a), and he points out the constant variations of these values. The average normal value of the three summer months is 51% at Turkeve (Table III), which is one of the dryest regions of the country. Under this value we find wet summers with 57% (1901), 55% (1912), 66% (1913), 64% (1915), and 58% (1926), while in dry summers this value is 44% (1904), 47% (1917), 46% (1919), and 40% in 1923 (Table IV/b). It is noted that extreme dryness used sometimes to occur ; thus on July 4 th 1930 and on June 15 th 1931 at 2 o'clock p. m. the air moisture was only 15% on the greater part of the Great Plains, as shown in the map representing the distribution of the air moisture (figs 1, 2). 3. Evaporation. Observations were made with Wild's apparatus. Tables V and VI show the observations at the stations of Tarcal and Kecskemét, extending over 35 and 27 years respectively. The height of the mean annual evaporation in these two places is 724 and 823 mm, while the summer evaporation amounted to 308 mm at Tarcal, and to 343 mm at Kecskemét. The summer evaporation at Tarcal had great values in 1904 (416 mm), 1917 (389 mm), 1921 (400 mm), 1930 (390 mm), and very small values in 1903 (279 mm), 1912 (276 mm), 1913 (235 mm), 1919 (219 mm), and 1925 (192 mm). In the period observed the sum of evaporation varied between 162 and 74 mm in June, 188 and 86 mm in July, 176 and 74 mm in August . From these data it can certainly be stated that the weather in this country evinces great variations and uncertainty, but the climate does not change in any definite direction and is not shifting towards a dry character. (In that case the values of evaporation would constantly increase.) 4. Rainfall. In this country we have rainfall observations from several stations, reaching back for 80 years. In Tables VII to X the data of four stations (Budapest, Magyaróvár, Szeged, Debrecen) are worked out, showing separately the sums per annum and in summer. Figure 3 (page 144) represents the mean values of these four stations, as well as the average values, which are 578 mm per annum and 169 mm in summer. From these data it can be stated that in the course of the past eighty years wet years and summers, as well as dry years and summers occurred, sometimes in groups and at times sporadically. According to these data, there were years with a total rainfall of under 400 mm, and even about 300 mm ; and in summers it very often happened that not even 50% of the summer average fell. It can be noted that very dry years occured more frequently in the earlier than in the later decades. On the other hand in wet years the sum of the annual rainfall is high ; at Szeged, for instance, it was more than 700 mm in 1897, 1915, 1919 and 1931 ; it amounted to 876 mm at Debrecen in 1915, to 941 mm at Budapest in 1915, and to 852 mm at Magyaróvár in 1900. Rainfall maps for several years are annexed to the article, and the author refers to the dry summers in 1887, 1917, 1935, and the rainy summers in 1915 and 1925 (figs. 5—9), when the amount of rainfall was once 75 mm, at another time 300—400 mm in the same place. In order to show the extreme character of the climate, the springs of two successive years are mentioned : the extremely dry spring of 1934 (fig. 10), and the spring of 1935, which was very abundant in rainfall (fig. 11). The effect of this wet spring was felt in the exceedingly hot summer of 1935, and it averted an absolute catastrophe. 2*