Geografie 1965, 70, 209-231
Extraordinary Character of Irrigation in Bohemia in Hydrological Year 1964
The paper gives the characteristics of water balance in individual watersheds in Bohemia during the hydrological year 1964. In the last years, considerable decrease showed in precipitation and consequently in the rate of flow on rivers in the watershed of the Elbe. From the viewpoint of precipitation, the hydrological year 1964 remains slightly below the normal (93 %) which, however, does not fall in with the fact that the mean annual rate of flow on the Elbe in Děčín made 59 % of the existing average. A comparatively great difference in the above figures was caused by the preceding longlasting period of draught and insufficient precipitation during the winter period. In the course of the year, the most humid months were August and October when waterlevels raised, in some places even floods were due to heavy downpours, especially in Eastern Bohemia. Individual areas in Bohemia have displayed great differences in regional distribution of precipitation and in the rate of water flow. Total annual precipitation kept between 40 and 90 % of the existing average. The most arid area in Bohemia in the course of the hydrological year 1964 was the watershed of the Ohře, most humid was Eastern Bohemia, especially the watershed of the Orlice. The uneven distribution of precipitation had direct economic consequences. The area of Eastern Bohemia - belonging according to the irrigation index by M. Konček (1955) in hydrological year 1964 to the humid territory - yielded a very good crops of agricultural products. On the other hand, in hydrological year 1964 the semi-arid to arid area of Western Bohemia had suffered catastrophic draughts and yielded poor crops. Average produce of agricultural product by hectar in the district of Louny (Northwestern Bohemia) reached only one third to one half of the produce secured in the district of Hradec Králové (Eastern Bohemia).
