Vízügyi Közlemények, 1945 (27. évfolyam)
1-4. szám - VIII. Szakirodalom
(13) Békás, i. e. these data are proportionally extented to the Creek Kis-Békás. Stage records and serial discharge measurements for the Creek Békás are known for longer periods. Drainage area of the Békás (the section south of the Lake Gyilkos where velocity is measured) is covering 41,0 km 2. In a twelve month period (April 1,1942 — March 31, 1943) being decisive for annual storage, run-off of the Békás totalled 15,8 million m 3. Ratio of discharges of the Békás and Kis-Békás creeks was not computed after the respective drainage areas, but according to actual water quantities determined on the basis of stage and discharge data relating to both of the creeks in the same period (May 1, — October 30, 1942). As runoff, during the above six months, of the Kis-Békás totalled 15,4 million m 3 and that of the Békás (see discharge curve in Figure 3.) reached 9,4 million m 3, ratio of reliable water quantities gives the figure of 1,64. Consequently in the twelve months decisive for storage effect, runoff on the Kis-Békás is totalling 15,8 x 1,64 = 25,9 million m 3 with a mean discharge of 0,83 m 3/sec. The annual run-off coefficient is: 60 per cent. In alternative II. united run-off for the decisive twelve months of the creeks Fügés (drainage area: 13,9 km 2, discharge after the ratio of drainage areas: 5,3 million m 3), Békás and Kis-Békás totals 47,0 million m 3 with a mean discharge of 1,50 m 3/sec. Hydrological investigations for determinating the necessary storage capacity were conducted with regard to a reservoir required by the mass curve of the Creek Békás and the results, taking the index of 1,64 into account, were referred to the actually designed Kis-Békás reservoir. The necessary storage capacity is determinated on the one hand by the discharge quantities and their distribution in time (see left lower part of Figure 4.) and on the other hand by the character of consumption. The graphical method applied in our study is taken from the manuscripts of E. MOSONYI's paper: ,,H ydrological Design of Larger Storage Reservoir s." In the left upper part of Figure 4. summation diagrams of consumptions of different types (their variations according to maximum annual consumption: T ma x is shown by diagrams 1—7 of the upper Figure on the right) are drawn so that the curves have common points. Maximum difference on the ordinate between run-off mass curve and consumption mass curve gives the necessary storage area, which assuming a consumption of character 1 (T mi n\T ma x = 0,8) totals 7,10 million m 3 for the Creek Békás (drainage area 41 km 2). Differences of the ordinates relating to the two curves represent quantity of stored water in the function of time. To give a better conspectus, these differences have been also separately drawn up from the axis of abscissae. The result multiplied by the formerly mentioned index (1,64) gives the necessary storage capacity for the Kis-Békás as follows: 1,64 x 7,10 =11,7 million m 3. (In the right lower corner of Figure 4. also capacities required by consumptions of different character can be read.) Assuming a required reserve capacity of 1,3 million m 3 necessary storage with alternative I. amounts to 11,7 -j- 1,3 = 13 million m 3 (when character of consumption is in conformity with curve 1). In case of regular consumption, according to Figure 4. needed capacity of the reservoir amounts to 6,45 million m 3. As annual run-off of the Békás totals 15,8 million m 3 and this figure, with the additional discharges of the creeks Kis-Békás and Fügés, reaches 47 million m 3, actually needed storage capacity with alternative II. (based on the ratio of water quantities in case of regular consumption) amounts to 19,2 million m 3 and 21 million m 3 respectively with the necessary reserve. Figure 5. shows the area and volume curves of the reservoir. Preliminary geological investigations have proved that the basin of the Kis- Békás is very suitable for storage purpose. Its subsoil consists of limestone covered by slate and sand-stone averting all danger of seepage. Towards the middle of the narrow gorge, where the dam is planned, we find first-class limestone offering good possibilities for building an arch dam (Figure 6.). For definite allocation of the dam further detailed investigations are needed. Figure 7. is meant to show the economy of storage. Curve 1 shows the required volume of dam, curve 2 gives volume of dam for one unit of the reservoir capacity and curve 3 indicates capacity for one unit of the dam volume, all as given in the function of the storage level. In case of alternative I. the volume of the dam is: 2310 m 3, while 1 m 3 of
