Vízügyi Közlemények, 1934 (16. évfolyam)
4. szám - XI. Szakirodalom
20 succeeded in integrating the equation pdt=qdt -\-dV , which holds for q water volume of p seconds entering the channel in a period of t, by setting up — on the basis of well-chosen approximate propositions — a relation between the d V water volume stored in the channel in a period of dt and the q water volume flowing down per second. By ingenious deduction Sr. Puppini rendered the final formula manageable, as is shown in equations 18—20, in which и is the water volume running off from one hectare of the watershed area, in second litres, a and n are parameters of the climatic probability function valid for the watershed basin, and v is a quotient — falling on one square metre of the watershed area — of the cubic contents available for storage in the channel. Sr. Puppini' s interesting analyses show that the proportions serving as the basis of his deduction, are also warranted for practice. By his procedure, all individual factors can easily be taken into account, with the exception of the form of the watershed area, but it does not seem impossible to render this characteristic particularity computable by modifying the к runoff coefficient suited to the form of the watershed area. Though Puppini's formula, in its original form, is far from complicated, Sr. Del. Pra has devised a skilful graphical table which simplifies it still further. Sr. Visentini expresses, by graphical drafting, the phenomenon of storage in the channel. He constructs the curve of water volume flowing through the channel profile, in conformity with the curve that depicts the variations of water volume entering the channel during the rainfall. The writer of the article shows by means of an example that Puppini's and Visentini's procedures give results closely corresponding, if the data are carefully chosen. From this he draws conclusion as to the reliability of the two methods, and proposes that the lessons of these two procedures should be taken into consideration, when a method suitable to conditions in Hungary is to be established. VI. THE ISLAND OF CSEPEL. BY E. KORPÁS. In the vicinity of Budapest the regional river-character of the Danube is of the lower section order, as is manifest in the formation of the Island of Csepel. This island has been gradually formed by the congregation of several islets of different sizes (see morphologic map), and terraces are found on it alternately with former river beds. The banks of the island are being partly destroyed, partly built up ; this can be recognized in ten different types of bank. The formation is especially interesting where the sand dunes stretch down to the bank. Not only erosion, but also deflation has taken part in the formation of the island. The winds from the NW — SE have massed up part of the sand carried from the bed of the Danube in several spots of the island. At present most of this sandy region ist forest-clad, but recognizable sand-forms, dunes and sandhills, still exist, though there are also destroyed forms, such as wind-furrows and wind-
