Vízügyi Közlemények, 1934 (16. évfolyam)

4. szám - XI. Szakirodalom

17 where the river has assumed a lower-section character, but is not excessively deteriorated, the irrigation water is conducted in canals, just as is done with the rivers of the Turan Plains ; while the water of rivers with upper and middle-section character is raised from the bed or from wells constructed in the vicinity. In the Po valley the situation is the same, because both the Po and its tributaries form their lower section there. For this reason, the Hungarian Great Plains cannot be compared, for possibility of irrigation, with the Po valley, the Turan Lowlands, or the basins of the rivers in Spain. II. WATER CONDITIONS OF THE HUNGARIAN DANUBE. BY W. LÁSZLÓFFY. I. Hydrographie description of the Danube basin. The topographic map shown in figure 1 indicates clearly that the Danube valley consists of three well-bounded parts : 1. the upper basin, extending to the mouth of the Morva river ; 2. the middle basin, bounded by the Carpathian mountains; 3. the lower basin in Roumania. It follows from this decided character that when studying that section of the Danube which is still under Hungarian rule, we have to consider the pre-war Hungarian Danube situated between the passes at Dévény and at the Iron Gates. That section of the Danube in present-day Hungary left unaffected by the Peace-Treaty of Trianon, is only a part of the Middle-Danube, whose watershed was called by Elysée Reclus, the famous French geographer, the most perfect geographical unit in the world. This unit, marked out and bounded by the Carpathian Mountains, formed pre-war Hungary. After describing the topography, the water régime (fig. 3. and 4), the geologic conditions, the distribution of rainfall and the temperature conditions, the writer treats of the annual average discharge of the Danube and its tributaries on the basis of figure 6. Then, from hydrogrades shown in figure 7, he proves that the régime of the Middle-Danube is governed by the discharge of the tributaries running down the Alps, while from Drave-mouth downwards the Danube is under the influence of the Drave, Tisza and Save rivers. II. Works of improvement of the Middle-Danube and their influence on the downflow-conditions. So far as we know, the first levee in the territory of pre-war Hungary was constructed at Somorja (at present in Czechoslovakian territory and called Samorin), but systematic river improvement was begun in the early nineteenth century. At the outbreak of the world-war, Hungary had spent 185 million gold crowns on river improvement works on the 940 kilometre stretch of the Danube extending from Dévény (near Pozsony which is called Bratislava by the Czechs) to the Iron Gates (at present Roumanian territory), and she spent 125 million gold crowns on the construction of a system of flood-control levees with a total length of 2824 kilometres. The writer of the article, examining the influence of this enormous investment on the water-régime, points out that the formation of dangerous icebarriers has been prevented, and in general the level of floods lowered. As a result of the regulation works, the changes in level of low waters do not exceed the range 2