ASSESSMENT OF WATER DEMAND AND IRRIGATION EFFICIENCY ON DRAINED LANDS UNDER CHANGING WEATHER-CLIMATIC AND AGROMELIORATIVE CONDITIONS

Abstract

Data base on the evaporation and water needs for agricultural crops in the different periods of their growing, depending on the climatic conditions, are the basis for the development of design and formation of operational regimes of water regulation, which has carried out by justifying the necessary methods of water regulation, types, structures and modes of operation of hydromeliorative systems and calculation of their parameters. To achieve this goal, the authors evaluated the weather and climate conditions in the Western Polissia of Ukraine and calculated the value of the evaporation in the studied conditions, planned and carried out a large-scale computer experiment, based on a complex of predictive-simulation models concerning the basic regime and technological variables of the hydromeliorative system’s parameters, climate conditions, water regime, water regulation technologies and productivity of the drained  lands for the schematized natural, agricultural and ameliorative conditions. The object of the study is the drainage system "Tsirska" in the Volyn region, which is typical for the region in relation to the natural land reclamation conditions. According to the long-term forecast determined the vegetative values of the total evaporation and the formation of water needs for the drained lands in the variable climatic, agricultural land reclamation conditions. Evaluated technological efficiency of different technologies of the drained land’s moistening. The obtained results can be effectively used to substantiate regime and technological decisions in projects of construction and reconstruction of hydromelioration systems of the Western Polissia of Ukraine, the need for further improvement of water regulation technologies of drained lands in changing climatic conditions, and the development of hydrotechnical adaptation measures to predicted climate changes in the region.