158 



WALTER TRANQUILLINI 



2000 



1500- 



1000- 



500 1000 1500 2000 



Annual precipitation , mm. 



2500 



Fig. 4. Annual precipitation in mm at several locations in the eastern Alps at different 



altitudes. (From Turner, 1961b). 



Table i 



Monthly, half-yearly and annual precipitation (mm) at Obergurgl at the timber-line 



(2070 m). Mean from 1911-1950 



I II III IV V VI VII VIII IX X XI XII Win. Sum. Year 

 55 73 53 83 87 92 105 103 80 77 71 63 392 551 944 



Therefore 60% of the annual precipitation falls in the summer half-year 

 and only 40% in the winter half-year. Precipitation is evenly distributed 

 throughout the summer; on the average there is precipitation every second 

 day, and every fourth day brings precipitation exceeding 5 mm. Periods 

 without precipitation do not last long, in summer 14 days at the most, 

 on the average 4 days ; only outside the growing season are there longer 

 periods without precipitation (up to 20 days) (Table 2). 



Table 2 

 Maximum duration of dry periods in days at Obergurgl from I954-I959 



