engleski

Research of climate change in the Croatian lowland in the frame of the COST Action 734

Knowing the temperature and precipitation regime, it is possible to determinate the main climatic characteristics in certain area, which helps in water, agricultural and energy managements. The water regime also plays an important role in agriculture, particularly in the planning of irrigation system. The Croatian lowland, which is a part of Pannonian flatland, is the main cereal-production region with three large rivers: Save Drava and Danube. Because of that it is the most important part of Croatia for agriculture and water. Thus, in this study the main aim is to establish the climate change and variability in the temperature, precipitation and water regimes in the Croatia lowland for the purpose of agricultural and water management. The linear trends of annual and seasonal temperature and precipitation were analysed using the long-term time series for the lowland main meteorological stations. For testing the significance of trends, the non-parametric Mann-Kendall rank statistics was applied. Positive linear trends in mean annual temperature occurred over the entire Croatian lowland with the maximal values in the NW Croatia. A significant increase in mean spring and summer temperatures appeared in the entire analysed area. The increase in temperature is faster in the previous six decades related to last century. Slightly negative linear trends in annual precipitation exist in peripheral NW part of Croatian lowlands and on the contrary, increase in the eastern part. A reason for that can be explain with a significant increase in autumn precipitation totals which caused the annual precipitation growth in eastern region in the last six decades. As distribution of seasonal precipitation is not uniformed, it causes difficulties in the water and agricultural management. It is also shown the discharges which are influenced by the change in temperature and precipitation patterns. River flow variations depend on the precipitation and evaporation as input in the watershed system, and water storages in the watershed that represent a stage of the system. The linear trend of mean annual and seasonal flow data were analysed using the long-term time series from representative hydrological gauging stations in Pannonian Basin (Fig. 2) and compared with the meteorological parameters. The significant decrease in mean annual discharge exists of the main Croatian rivers: Sava and Drava. The trend analyses of seasonal hydrological data indicate a decrease in discharge in the NW Croatian part in the all seasons. However, in the eastern part of Croatia positive trend of discharge reveals in autumn which is accordance with autumn precipitation growth.

precipitation ; temperature and water regimes ; linear trend ; Croatian lowland

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