Kotykovych I. Development of a flood protection system for poorly drained areas.

The thesis presents the results of research on vertical and horizontal drainage in poorly drained areas. The condition of the drainage, efficiency of its operation and the mechanism of flooding process development when operating the existing protection systems have been specified. The conditions of drainage functioning, groundwater regime, its spatial distribution and the necessity of improving the drainage systems have been determined. It is established that vertical drainage is a powerful means of restraining flooding process development and protects areas against flooding during the period of stable operation, but insufficiently influences on the flooding processes in the periods of heavy precipitation and snowmelt. The flooded areas do not change significantly over a long period, and the drainage operating regime is influenced by natural, climatic and water conditions, which necessitates its improvement. To ensure the protection of poorly drained areas against flooding, taking into account the basin management principle, the existing measures and tools have been improved, which include regulation of the Kalanchak riverbed, ensuring the operation of vertical drainage wells, setting up of horizontal cut-off drainage, creating a system of self-flowing reservoirs etc. A drainage system has been developed and its parameters have been scientifically substantiated based on the simultaneous operation of vertical and horizontal drainage facilitated by the drainage capacity of a small river, which will ensure their joint drainage effect, interception of soil water flow from the irrigation canal, decrease in groundwater level and increase in the effectiveness of settlement protection against flooding. The proposed measures and tools will reduce the energy consumption of existing protection systems and maintain groundwater levels below critical values, provide a favorable environmental and reclamation condition and reduce the risk of flooding in the areas of irrigated agriculture. Key words: poorly drained areas, flooding, precipitation, groundwater levels, protection systems, set of measures, horizontal and vertical drainage