Evaluation of Climate Change in the Rice-Growing Zone of Ukraine and Ways of Adaptation to the Predicted Changes

Abstract

The article presents the results of the analysis of the current state of weather and climatic conditions and evaluation of their predicted changes for immediate and distant prospects in the rice-growing zone of Ukraine. Studies were performed on the example of the Danube rice irrigation systems (RIS) in Odessa region with a total area of 13,678 ha, which are located in lands prone to salinization. The following major meteorological characteristics were investigated: air temperature, precipitation, relative humidity and air humidity deficit, as well as derivatives: photosynthetically active radiation and water availability coefficient (precipitation/evapotranspiration ratio). Retrospective analysis and forecast of meteorological regimes by typical groups were done (estimated years) of vegetation periods of target years in view of general heat and moisture provision: very wet-p = 10%, wet-p = 30%, middle-p = 50%, dry-p = 70%, very dry-p = 90%. The basis of forecast calculations is the results of studies of possible changes of air temperature by the models of Canadian Climate Center "CCCM" and of the United Kingdom Met Office "UKMO" which foresee an increase in average annual temperature up to 4 degrees C and 6 degrees C relatively-provided that the doubling CO2 in atmosphere occurs. The main trends in changes of meteorological characteristics and their possible effect on the conditions of functioning rice irrigation systems as well as on the natural and ameliorative state of irrigated areas were identified. The most significant influence on the condition of fonctioning of RIS is air temperature, which directly effects duration of maturation and total value of water consumption of rice crops. It is established that in the last decades a significant increase in the average value of air temperature for the growing season happened (April-October): 1981-1990-16.9 degrees C, 1991-2000-17.5 degrees C, 2001-2010-18.1 degrees C, 2011-2017-17.7 degrees C. It is determined that at the existing rates and levels of weather and climatic changes, we should expect a significant deterioration of functioning conditions of RIS and natural reclamation state of irrigated land. In this regard, were examined core measures regarding the adaptive potential enhancement and development of the rice-growing zone under the conditions of climate change.