L. Pysarenko, A. Krukivska

FEATURES OF SPATIAL DISTRIBUTION OF HEAT RESOURCES OF THE TERRITORY OF UKRAINE IN THE PERIOD OF CROPS’ ACTIVE VEGETATION

      In this article the research results of spatial distribution of the sum of active temperatures (SAT) for the second part of the XX century and the beginnings of the XXI century over the territory of Ukraine have been presented. The regional features of the long-term changes of heat-supply resources in the period of agricultural crops’ active vegetation in accordance with climate change have been determined.

      Index SAT covers the period of active vegetation which is limited by spring and autumn thresholds through 10°C. Averaged decadal temperature, spring and autumn thresholds (dates of transition of average daily temperature 10°C) of 73 meteorological stations were used for calculations of the sum of active temperatures. Calculations were done by using program Excel and programming language VBA. Maps of spatial distribution of previous mentioned index were built in program Surfer by using kriging interpolation.

      It has been given the characteristics of averaged SAT for 55-yearly period of research (1961–2015) and comparative analysis of two it’s parts: standard climatological period (1961–1990) and subsequent period (1991–2015). Results’ are obtained and presented for different parts of physico-geographical zoning of Ukraine.

      According to SAT distribution in 1961?2015 has been divided into 6 zones with range 2100°C to 3500°C over the territory of Ukraine. For both parts 1961–1990 and 1991–2015 6 zones have been distinguished. Comparing these two periods, different heat-supply zones have some differences in the distribution and configuration of borders which are connected with increasing of the sum of active temperatures during the last 25 years.

      According to the results of the comparative analysis of spatial distribution and long-term dynamics of SAT for current period (1991?2015) and of standard climatological period for the 2nd half of the XX century (1961?1990) it has been revealed the general tendency for heat resources increasing in the period of crops’ active vegetation. It is observed that heat zones have shifted from the South to the North. The biggest changes in SAT accumulation are present in the Western Polissia and Carpathian physico-geographical regions which belong to insufficient heat supply zone. The same tendency is in the zone of high heat-supply on the Southern part of Ukraine. Long-term gradients of this index have reached 300°C in this area. Changes in configuration and zones’ locations cause slight heat increasing in some regions of Western and Central Lisosteppe. The similar situation with not big quantitative changes in long-term variations of SAT is in the Eastern Steppe. At the same time this respective high-potential zone of heat has been expanded on North.

      Key words: agroclimatic resources, heat supply, sum of active temperatures (SAT), period of active vegetation.