engleski

Influence of climate change on soil water regime in Koprivnica-Križevci county

The influence of climate change on soil water regime was investigated in the area of Koprivnica-Križevci County (Republic of Croatia). Water balance calculations were done for three climatic stations using Thornthwaite and Palmer water balance methods. In the 12-year period (from 1991 until 2008), compared with the previously observed 30-year period (from 1961 until 1990) the increase in average mean annual temperature was 1°C, and the increase in mean annual precipitation was 5 mm. Regarding the global warming, there was an increase in plant water potential during the investigated period, however, sufficient quantities of water were not available to plants. Compared with the previous period and according to Thornthwaite and Palmer methods, there was an increase in water deficit. Negative linear trend in precipitation was detected for all climate stations in the investigated area (p>0, 05) as well as positive linear trend in mean annual temperature (p<0, 05). The calculation of linear trend in water deficit in soil, according to Thornthwaite method, shows that by the year 2020 there could be an increase in the water deficit by an average of 13 mm (p>0, 05), whereas according to the Palmer method there could be an increase by an average of 9 mm (p<0, 05 only for the climate station in Križevci). Calculated by the Thornthwaite method there could be a decrease in water surplus by an average of 13 mm (p>0, 05) in the following 10-year period. Similar results were obtained using the Palmer method, and there could be a decrease in water surplus by 18 mm in the same period. However, statistically significant values were obtained only for the climate station in Koprivnica (p<0, 05). Frequent droughts and consequently the deficit in soil moisture storage adversely affect the yield of crops grown, and in the near future the consequences could be even greater. Therefore, it is considered necessary to provide new water resources in the County, and, of course, respond to a greater irrigation demand, as well as to apply the methods of soil management which have a beneficial effect on moisture conservation.

climate change; droughts; soil water regime; water balance

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