Vízügyi Közlemények, 2003 (85. évfolyam)

3. füzet - Orlóci I.-Szesztay K.: A vízvagyon állapotának változása a XX. században

Л vízvag)'on állapotának változása а XX. században 413 aquifer of the USA. which is one of the most significant near-surface water-bearing layers of the US. The forced growth of global trade, a characteristic feature of the economy of the 2()

Ih Century, also has an important water management implication, as the creation of most products requires water quantities, which exceeds several hundred or even thousand times the weight of the product (Tabic VU.). Therefore the world trade comes along with a "virtual" export of water, which amounts in a global comparison to 15% of the total water uses. This is well reflected by the data of arable lands and population of various countries (Figure

.?). One of the heaviest problems of the future of water resources is related to the likely rapid global warming and subsequent drying of the climate. This has an impact not only on the magnitude of the utilisable water resources luit also on the water demand, especially on the irrigation water demand (Figure 4.). A characteristic positive feature of the period after the Stockholm environmental conference of the UN in 1972 was that the role of the non-governmental organisation has increased in the field of international co-operation. The analysis of trends have shown that we will face increasing water shortages and other water problems in the coming decades (Tabic VIII). In the second part of the study, which deals with the Hungarian conditions and trends, the water resources of Hungary are analysed in the international context. If one analyses the water resources of a country in a complex way, considering, apart from the precipitation onto the country's territory the inflow from upstream countries and also the subsurface water resources then Hungary can be listed into the group of countries having relatively good supply of water, considering also the statistics of the population densities and agricultural land (Figures 5. 6 and 7). The state of Hungary's water resources is presently defined by the expectations of integrated water resources management and its further development (sec also Figure 2). For the evaluation of the social processes and natural factors, which form the expectations, one needs to review the historic background along with the future tendencies. Considering the natural factors the major problem of Hungarian water management is the extreme variability of surface water resources and the tasks of water management arc also related to this (Figure 8). The policies of the water sector should be aimed at securing direct and continuous support to the development of information technology and institutional frames, along with the improvement of communal services, international co-operation and of the intellectual and financial resources. * * * Veränderungen des Zustandes des Wasservermögens Während des XX. Jahrhunderts von Dr.-Ing. István ORl.ÓCl und Dr.-Ing Károly SZESZTAY. DSc Das XX. Jahrhundert war eine Zeitspanne, während welcher sowohl der Bevölkerungszuwachs, als auch die wirtschaftlichen und technologischen Veränderungen alle Grenzen sprengten und das Wachstum alle frühere Vorstellungen übertraf (Tabelle I). Die vorliegende Studie hat zum Zweck, die im Süßwasservermögen der Erde hinterlassenen Spuren dieses stürmischen Jahrhunderts anhand einiger Daten und herausgegriffener Beispiele zu verfolgen und sodann im Rahmen dieses globalen Gesamtbildes das Ausmaß und die strukturelle Zusammensetzung des Wasservermögens von Ungarn zu bewerten, schließlich einige schwerpunktmäßige Fragen der den Erwartungen einer nachhaltigen Entwicklung angepabten integrierten Wasserwirtschaft sowie die Hauptaufgaben der dieselbe in einen Rahmen fassenden Spartenpolitik zu erörtern.