IRRIGATION WATER DEMAND AND INFRASTRUCTURE DURING DROUGHT.

Ensuring sustainable water supply, in particular in agriculture, requires knowledge of the local hydrologic cycle and up-to-date assessment of the water resources, determined by the new requirements of agricultural holdings water demand for irrigation and the level of irrigation infrastructure, especially in drought. The aim of the present work is to offer an informed solution for water use management in a pilot irrigation system. The study has been carried out by a balance method through a computer program for compiling a dispatching schedule, using rules for filling the reservoir with taking into account the ecological flow and data about the annual inflow into it and water consumption for irrigation in the pilot section of a selected irrigation system for the period 1990÷2019. The analysis of the results regarding the necessary volumes in the reservoir to guarantee the irrigation with characteristic exceedеnce probability under the existing conditions defines the respective solution. In years of drought, the volumes, the declared needs and the water supply regime should be reassessed in compliance with the priorities of water use. The study proves the need for a detailed water balance assessment for each irrigation system and mapping out adaptive measures and actions in case of drought, which is important for developing appropriate operational strategies for water management in any particular area of Bulgaria. [ABSTRACT FROM AUTHOR]