FORMATION OF WATER SUPPLY MODULES DURING IRRIGATION OF DRAINED LAND UNDER CLIMATE CHANGE AND LAND RECLAMATION CONDITIONS

To justify the calculated water supply module for subsurface irrigation of drained lands, as well as for the drainage flow module, empirical, analytical, water-balance methods are similarly used, or it is determined according to recommendations without sufficient economic and environmental justification, which does not meet modern requirements. Therefore, on the basis of simulation modeling for the conditions of the Ukrainian Polesie, the dynamics, as well as the current and weighted average values of the water supply modules during subsurface humidification in various weather and climatic conditions, including taking into account their possible changes, are established, their significant variability in time and space is established, normalized curves of the water supply module security for the main cultivated crops (cereals, potatoes, grasses) on mineral and peat soils are constructed. It is established that both the current and average values of the water supply module under the studied conditions, similar to the drainage flow module, have a pronounced variable character in climatic conditions, the type of crops grown and the type of soil. Its value, both for the identified main factors and for the system as a whole operating in the subsurface humidification mode, differs significantly (more than several times), first of all, both from their maximum current 2.0-3.0 l center dot s(-1)center dot ha, and from the average vegetation values of 0.39-0.96 l center dot s(-1)center dot ha, which significantly differs from their recommended calculated values. At the same time, the water demand of cultivated crops increases almost two to three times. This makes it necessary to take into account this variation of this indicator by improving existing methods and approaches to substantiating the calculated value of the water supply module, when developing projects for the reconstruction, modernization, construction and operation of such facilities.