Vízügyi Közlemények, 1995 (77. évfolyam)

3. füzet - Domokos Miklós: Az esetleges éghajlatváltozás és annak vízkészlet-gazdálkodási hatásai

Az esetleges éghajlatváltozás és annak vízkészlet-gazdálkodási hatásai 369 Winter.

./.: The caracterization of hydrometeorological elements. In: Conference on Climate and Water, Helsinki 11-15 September, 19X9 WMO: Fourth Planning Meeting on World Climate Programme. Water, Paris, WCAP-5. WM< )/TD-No. 271. Geneva. 1988. Wood, E. F.: Land Hydrology Parametrization for Climate Models. Chapman Conference of AGU on „Hydrologie ASpects of Global Climate Change", 12-14June. Lake Chelan, Washington, USA, 1990. Yell. T. C.-Wetherlaiul, R. T.-Manahe, S. : A model study of the short-term climatic and hydrologie effects on sudden snowcover removal. Mon. Wath. Rev., 111, 1983. * * * Potential change of the climate and its water resources management implications by Dr. M. DOMOKOS. Civil Engineer. Mathematician On the basis of about 180 publications of the relevant literature, many more than included in the list of references, the author attempts to formulate the conclusions that can he drawn, on the basis of knowledge gathered up to 1994, on the potentially occurring changes of the climate and on their hydrological and water management consequences. The author summarizes in the first step the so far observed or unobserved marks (indications) of the climate change. The CO, content of the atmosphere has, as indicated by Figure 2., increased by 27% since the industrial revolution and within this by 13% in the past 3 decades. Consequently it is difficult to estimate the time when the concentration increase of 100% and 300% (scenarios 2XC0

9 and 4XC()t), considered mostly the input data of climate models, will be reached. Examples of changes of air temperature, precipitation, surface runoff, snow and ice masses, observed in the past decades, are presented in Figures 4-14. Most of the examples confirms the statement of the relevant committee of the Hungarian Academy of Sciences I MTA, 1991 ), according to which "it is still disputed whether the change of the climate of the Earth, due to the anthropogenically induced increasing greenhouse effect, has already commenced or not". The author also describes the methods usually utilized for assessing the expectable hydrological consequences of the change of the climate. Apart from the paleoclimatological methods (Figure I

.), that is suitable rather for forming attitudes than for making forecasts of practical values, and from more recent analyses of climatological anomalies the two basic methods of impact assessment are: the general circulation models (GCMs) and the autonomous hydrological models (AIIMs). The main objective of these latter is to aid the catchment-basin scale interpretation of the results that have been obtained for the globe or for a given latitude zone by the GCMs. The author analyzes the numerical results of assessments (predictions) made by GCMs and AI IMs for the various elements of the hydrological cycle and for the various CO-, scenarios, taking geographical (according to latitude zones) and temporal (monthly) distributions into consideration (Figures 15-32). Generalizing, it can be stated that GCMs have different structures and are based on different assumptions and simplifications. Consequently thev yield much differing forecasts for the various hydrological elements event in the case of identical scenarios (which are themselves rather uncertain ones, as discussed above). This is especially well illustrated by Figures 15. and 25. Finally the author discusses in section 4. the effects of a potential climate change on water management. Figures 34-36, illustrating the expectable loss of the capacity of existing reservoirs, the increasing risk of not being able to supply water from them, upon the effect of hypothetic climate changes, demonstrate these effects especially well. Similar increase of risk can be expected in other