Vízügyi Közlemények, 1970 (52. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(89) graph, as well as the graph of the inundated areas. The problems associated with the practical introduction of the method are then considered: a

) The analysis of potential errors introduced by the simplifying assumptions and the method for measuring the errors committed and b

) the possibilities for further simplifying the computation method, to reduce computer time. c

) The results are analysed for their sensitivity depending on the variation of parameters, in order to permit d

) the development of methods required for the determination of parameters which change both in time and in space, and the necessary aids. The problems under a

) are considered in Chapter 2 (Figs. 2 to 4). The errors introduced in simulating the process of concentration of waters on the terrain and in the canals are analysed separately and then in their combination, in order to estimate the difference between actual and computed values. The problems under b

) are considered in Chapter 3 ( Fig. 5). Following a review of the possible metods of error seeking, the method of the double-mass curves is adopted to introduce criteria for estimating the magnitude of errors. The problems under с

) are considered in Chapter 4 ( Fig. 6). The values of a set of parameters describing a practical situation are modified in sequence, the percentual change in the result following a given percentual change of individual parameters is determined. In other words the weight of each of the parameters is determined. The problems under d

) are considered in Chapter 5. The methods based on actual hydrological observations and empirical findings are considered in sequence used successfully in determining the parameters, including also the question of optimization. It is concluded that the prerequisites for the routine application of the method are, on the one hand, the development of aids relating parameters to areal and meteorological conditions, and on the other, the development in both quantity and quality of the fleet of electronic computers available in this country. 8. INTERNATIONAL COURSE OF LAND DRAINAGE IN THE NETHERLANDS Wageningen, 1969 By M. Kálmán and P. Magyar, Ph. D. Civ. Engrs. (For the Hungarian text see pp. 474) The authors were participants of the 8

t

h International Course of Land Drainage organised in 1969 by the International Agricultural Centre (IAC) in the Netherlands. The report on their impressions and experiences has been written with the objective of satisfying professional interest and to offer help to those engaged at home in agricultural water management by describing the methods encountered during the study of agricultural water management in the Netherlands. In Chapter 1 a brief description is presented on the agricultural education centre in Wageningen, where about 50 research institutes and services are affiliated to the State Agricultural University. The activities of the International Agricultural Centre, as well as the educational work at the International Institute for Land Reclamation and Improvement (IRLI) are described more in detail. The professional management of the Course Land Drainage was the responsibility of the latter. The curriculum of the course, the practical classes, professional study tours are briefly reviewed in Chapter 2, containing also an evaluation. The lectures at the course were divided into 8 sections: preliminary subjects, the fundamentals of agricultural water management, preliminary design work, engineering work, designing practice, contemporary problems in land drainage, special problems in land drainage, and economics of land drainage. It is noted that in the last months the participants were divided into three groups, engaged intensely in seepage,