Vízügyi Közlemények, 1971 (53. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(12) In Section 1 it is concluded that the prerequisite lor the reorganisation of economy was the establishment of new bases of production. The administraional organisation was considered unsuited for implementing the regional development plan, so that it was found necessary to create a new economic ancl legal organisation, securing the flexibility of enterprise management and the implementation of a centrally defined and controlled program. This form of organisation was the so-called mixed enterprise. For implementing the plan for large water management organisations have been created in Southern France, namely that of Languedoc, Provence, Gascogne and Corsica (Fig. 1), the activities of which are characterized by complexity. These enterprises have been granted concession of 75 to 80 years duration lor developing and operating irrigation agriculture in the region under their scope. Beyond creating the engineering economic prerequisites of irrigation, their responsibilities include the construction of water supply systems to the population and industry alike, the exploitation of storage opportunities, beach control, afforestation, the modernisation ol settlements, as well as the preparation of preliminary agricultural and economic reports, together with the engineering and economic cooperation to ensure economic efficiency in realization. «• In Section 2 the significance of irrigation in France is analysed. About 700,000 hectares are irrigated with surface and sprinkler irrigation playing equal importance. Round 350,000 are envisaged for irrigation development exclusively by sprinkling. In the Y-th five-year plan (1965 to 1970) irrigation development was scheduled on 180,000 hectares, of which 78,000 hectares lies on territory shared by the abovementioned concessionary enterprises. During the Vl-th five-year plan irrigation development over additional 400,000 hectares is considered necessary. The center of gravity of irrigation demands is in the south-southeastern part of the country, where 28.9% of the total demand is recorded. The economic efficiency of investments is analysed in Section 3. It is concluded that where the funds available are insufficient for the realization of plans ensuring an identical level of engineering completion, the profitability index is adopted as the basis for determining priorities. The estimation of the profitability index is described here in brief. A method for establishing water rates is described in Section 4. In this connection the economics of water rate determination are considered first, followed by the pricing policy. 2. Fehér, Л., Civ. Engr.: Bonding of reinforcement in concrete diaphragm walls. (For the Hungarian text see pp. 69) In load-bearing concrete diaphragm walls firm bonding between the conrete and the reinforcing steel is required. On the other hand, the slurry used lor the construction of the wall consists of bentonite, or some other clay, may adhere to the steel when the concrete is poured and thus prevent the development of a good bond. Experiments abroad have shown the loss in bonding strength to be significant, attaining as much as 80%. During experiments in Hungary the effect of both clay- and bentonite slurries has been studied using smooth and ribbed reinforcing steel of 20 and 28 mm diameter. fn these experiments it was found that overlapping and bonding lengths should be increased by 50% of the value commonly used. 3. Csuka, J., Civ. Engr.: The effect of the Tisza II Barrage on sediment- and channel conditions. (For the Hungarian text see pp. 74) A reservoir of 265 million cu.m capacity will be created above the Tisza II Barrage, the volume of which will be increased to 400 million cu.m in the ultimate stage of development. Sediment transportation and consequently channel conditions both upstream and downstream of the reservoir are certain to undergo appreciable changes. Present channel conditions of the Tisza River are characterized by the fact that after the regulation works completed in the second half of the 19th century the stream tends to establish a relative equilibrium. Sediment transportation in several