Vízügyi Közlemények, 1958 (40. évfolyam)

4. füzet - VII. Kisebb közleménye

(61) the first stage of realization to be completed by 1967. The estimated cost of the first stage amounts to 5324 million JMP-s to be recovered in three and a half years by increased agricultural crops and by the energy generated. c

) The system of the Hai River with a catchment area of 205 000 sq. kilometres comprises thé watercourses in the Peking area and provides a common estuary for them into the Pohai bay (Fig. 10., Table V.). Most important in the system is the Yungting River named for its characteristics, the „Little Yellow River". Over the alluvial plain, the river flows in an elevated bed between levees. 7 major breaks occured over this reach between 1912 and 1947. In 1917 and 1939 Tien-tsin was flooded and the navigation waterway for seagoing vessels between the sea and Tien-tsin was silted up. It is intended to cut flood peaks by means of reservoirs constructed in the mountains. Of these the Kwanting reservoir has already been completed, which constitutes, at the same time, the main project of the Yung-ting development controlling 97 per cent of the entire catchment area. The earth dam built of differently graded bed material, with a trapezoidal cross section is 45 m high and has a watertight core. The reservoir created thereby has a storage capacity of 2,27 cu. kilometres. A head of 35 m is created and utilized by a power station having an installed capacity of 30 MW and producing annually 70 million kWh (Photos 17 to 19). d

) The training and development of the greatest river in China, the Yangtse Kiarig is a great task with which Chinese engineers are confronted. The catchment area covers 1 830 000 sq. kilometres and the length of the river is 5590 kilometres. The river has a fairly uniform regime (Fig. 17) and carries relatively little sediment. The reach upstream from Tchang is enclosed at both sides by levees. Concurrent floods of the tributaries often create difficult situations here as e. g. in 1931, when also Ilang' how was inundated. Levees were lengthened and strengthened over this section between the years 1945 and 1952 and these coped successfully with floods that occured since. Flood damages will be eliminated entirely by creating reservoirs both in the mountains and in the plains. Outstanding among these projects is the 180 m high dam to be built across the llan River to provide storage for 38,5 cu. kilometres of water and irrigation for 800 000 hectares. Part of the stored water is to be diverted into the catchment areas of the lluai and Yellow Rivers. The proiect of a 235 m high dam across the Three Gorges above Ichang, to be realized within 10 to 12 years is of yet greater significance. A live storage capacity of 105 cu. kilometres will be created. The 1000 year flood of 96 500 cu. m/sec on the lower reaches of the Yangtse will be reduced to 30 000 cu. m/sec, and thereby, all flood control problems on the lower reaches will be eliminated. Power development projects in the Yangtse valley are of similar importance. Several of these structures have already been completed, or are under construction. Of historical interest is in the same system the irrigation development Tubiangyien constructed 2000 years ago and still in operation. e) Plans for the development of the Heilunkiang (Amur) River are prepared in cooperation by Chinese and Soviet authorities according to principles similar to those mentioned previously. Planning was started in 1956. f) Based on personal experience, future development plans for the Hangchow bay are also described. The project consists essentially of closing the bay and of utilizing thereby its tidal energy. Tidal phenomena in the' Hangchow bay are described after observations of the Hungarian professor Cholnoky in the year 1896. Mention is made further of the existing old sea defences, projects for the modernization of wich are under preparation. Scientific research institutes related with hydraulic engineering, hydraulic laboratories (Fig. 19), the hydrological service and the education of hydraulic engineers are discussed in conclusion, and their scope of work, aims and development plans are described. * The Author wishes to express his thanks to all Chinese authorities and colleagues who assisted and contributed to the success of his sLudy tour in their country. (Author's summary translated by Z. Siilvàssu с. eng.)