ASSESSMENT OF
THE POTENTIAL IMPACT OF CLIMATE CHANGE
UPON SURFACE WATER RESOURCES IN THE PRAHOVA RIVER BASIN
M. RETEGAN
Abstract. - The aim of the present research is the determination of the impact of possible climatic changes in the 21st century upon surface water resources in the Prahova river basin using the WatBal model (a mathematical-hydrological water-balance model). The analyzed river basin covers an area of 3682 km² and is located outside the curvature of the Carpathian Mountains, in an area where the altitude varies between 60 m and 2500 m. In accordance with the altitude, the annual precipitation varies from approximately 550 mm/year in the plain area to over 1000 mm/year in the mountain area and the evaporation-transpiration between 850 mm/year in the plain area to 500 mm/year in the high areas. On the other hand, due to a very high variability of weather conditions, droughts, as well as excessive humidity periods, may occur during the year. WatBal is an integrated water balance model developed for assessing the impact of climate changes on a river basin runoff. This model has essentially two main modelling components. The first is the water balance component that uses continuous functions to describe water movement into and out of a conceptualized basin. The second component is the computation of the potential evaporation-transpiration processes. Monthly data series recorded at 5 weather stations and 1 runoff gauging-station during the 1961-2007 period have been used for the calibration of the WatBal model to the local conditions of the area. Finally, the paper focuses on the values of the mean monthly discharges at Adāncata river station on the Prahova River, estimated in the above-mentioned hypotheses. The paper analyses the influence of potential climatic changes, expressed by a wide range of climatic scenarios, upon the average water resources in the Prahova river basin. It has also been taken into consideration the below average water resources, expressed by the minimum-monthly average flow and characteristic to low-water periods as well as the above average water resources, expressed by the maximum monthly average flow and characteristic to high-water periods.
Key words: Prahova River Basin, climate changes, WatBal model, surface water resources