Vízügyi Közlemények, 1969 (51. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(16) works it appears today safe to conclude that channel conditions in the ford and over the section downstream developed as a result of regulation in the favourable manner contemplated. On the other hand, over the upstream section they deteriorated appreciably. This may be traced back to the circumstance that as a consequence of severe contraction the water was backed up locally upstream of the ford, which resulted in the deposition of bed load. This should be regarded as a demonstration of the fact that problems over the Upper Danube cannot be solved by local measures and that regulation w

rorks must be carried out according to a uniform approach over the entire reach (Figs. 18 and 19, Table III). The general plan for regulation along the section between R. Sts. 1942 and 1816 kom of the Upper Danube was approved by the CTC in November, 1964. The creation of continuous banklines and the regulation of branch systems is envisaged in these plans. Regulation work was started according to these principles in 1966, starting with the branch system at Cikotasziget along the right-hand bank. INTERPRETATION OF AERIAL PHOTOGRAPHS IN KARSTWATER RESEARCH By Rádai, Ödön, Geographer (For the Hungarian text see pp. 97) The conventional methods of karstwater research, namely field exploration mapping, geophysics, have recently been completed by the interpretation of aerial photographs as a valuable source of information. In the following it is intended to explain why aerial photographs are suitable for contributing entirely new, or important complementary data to the work of karstic research. The essential functions of 1. reading, 2. measurement and analysis, further 3. intepretation of aerial photographs are described in detail together with the relationships developed, the substance of direct and indirect interpretation. A pair of stereo-photographs are shown in Fig. 1 — 2, illustrating a dolomilic, karstic area which forms part of the southern side of the Keszthely range along Lake Balaton in the southwestern part of Hungary Along the lines A-C-K-F-B, C-D

, E-H-F, as well as I-H-B, C-M-B and J-K in Fig. 1 are situated the crushed waterbearing zones 11-B, C-M- paramount importance for karst-water exploration. The existence of fault lines is demonstrated by the terrain contour, the presence of powdered dolomile and the emergence of lukewarm karstic springs. Slopes of powdering dolomite are to be seen along the signs С, II and At. Springs emerge at D, F and M, as well as В at the points indicated by arrows. During the interpretation important roles are attributed to slope facets, the arrays of vegetation (e. g. at the arrow J

) indicating the strike of strata, as w

Tell as to the dolomite horst at point B. The tracing of faulting, crushed zones over areas covered by sediments and rubble is made possible by this horst. Photographs in Fig. 4 Laken from the base of the slope at point С towards the horst, respectively showing the north-western face of the quarry in Fig. 5 demonstrate the foregoing considerations. Further analysis of tectonic movemenl is made possible by the sinks developed at Lhe fault crossings on the debris-covered valley floor shown in Fig. 3. These sinks serve as intakes for the precipitation and snowmelt water from a considerable area. In Fig. 6 the quarry at H and the dolomite horst are shown with clearly visible striking. Figs. 7 and 8 illustrate the quarry east of point G. In Fig. 7 a clearly identifiable reverse fault is shown on a layer striking north, while Fig. 8 shows the quarry in which the reverse fault is observable. Except for the pair of stereo-photographs taken with a vertical axis, all photographs have been taken by the author, including the aerial photographs with an inclined axis. On the basis of information gained from the interpretation of aerial photographs a borehole for observing karstic water levels will be sunk at the point marked with a cross at A. However, relying on the picture gained from the interpretation borehole sites can be selected with much greater reliability at numerous other points as well.