Vízügyi Közlemények, 1971 (53. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

(11) maximum temperature and precipitation during the period. For a formally correct representation of the relationship the most important plants requiring to be irrigated have been compiled in a table indicating lor brief time intervals of the season the water demand of the plants as a function of temperature. The family of curves constructed from these tables were expressed mathematically first in the form of power functions, subsequently by a set of linear functions, fi' the weather forecast for the next day is available, the discharge to be diverted through the main intake of the irrigation system can be estimated with an accuracy and reliability comparable to that of the forecast. The set of functions can be converted also for irrigation systems of different size, but with the same combination of plants. Promising attempts have been made at applying the method for compiling on the basis of long meteorological, or hydrological records plans for the monthly, annual, or even multi-annual water demand, of power consumption of large irrigation projects. Checks performed using operational data for brief periods of systems larger than МО,ООО hectares revealed the agreement to be good. Checks against actual data for smaller systems of a few thousand hectares are contemplated in the near future. ON THE RELATION BETWEEN THE THEORY OF FLOW-THROUGH SYSTEMS AND LINEAR SYSTEMS Horváth, Imre С. E. (For the Hungarian text see pp 44) The flow-through theory, which can be applied with great success to the description of hydraulic phenomena in a variety of basins, thus also basins at wastes treatment plants, can be approached mathematically also by considering theory of linear systems. In this form it lends itself more readily to generalization. The fundamental properties of linear systems have been analysed in the work of O. Levenspiel. The transient function (2) is the response to the generation having the form ot the unit-pulse function (1). The introduction of a tracer may be regarded as a generation. The other function characteristic of the system is the weight function responding to the pulse function of Dirac. The differential-integral relationship between the transient- and weight functions can be demonstrated (8). If feed is in accordance with the Dirac function, the response is the flow-through curve, consequently this also characteristic of the system. Operations with the functions characteristic of the system are facilitated by the Laplace transformation, which has already been used by several authors for the computation of flow-through characteristics (6, 8). Consequently the mathematical principles can be applied for the investigation of flow-through systems. BRIEF PUBLICATIONS AND REPORTS 1. Gergely, S., Mrs. : Ail economic analysis of water policy ill France (For the Hungarian text sec pp. 61) During a study tour in France the engineering-economic measures in the Provence were studied which were taken for the reorganisation of the region underdeveloped because of adverse natural conditions, in order to create an economic balance and to attain a production and income level corresponding to the natural average. According to the improvement program the measures are aimed fundamentally at the establishment of the criteria for contemporary water management.