An analysis of irrigation efficiencies over time in Iran

Irrigation efficiency is one of the important and common indicators in water consumption management, which has been used for a long time by researchers and irrigation experts to design and evaluation of irrigation systems. This index is defined by the ratio of water consumed by crops to water diverted from a source. It is a relative quantity that has the components of conveyance, distribution and application efficiency (the ratio of water used by plant to water used in the field). This research aims to evaluate irrigation efficiencies in Iran and its trends over time. The results of researches and studies conducted in Iran during the past decades have been collected and analyzed. To do this, two databases, including the irrigation efficiency database (Abbasi et al., 2015) containing 1900 efficiency data published in 1991-2015 and the database related to the results of the irrigation applied water and water productivity project made from 2016 to 2020. Results showed that the general trend of changes in irrigation efficiency in Iran has been positive and increasing. So that the average application efficiency, conveyance and distribution and total irrigation efficiency were 74, 77 and 57%, respectively. The total irrigation efficiency in Iran is more than the total irrigation efficiency in developing countries and close to the efficiency in developed countries. The analysis and evaluation of the irrigation efficiency over time showed that part of the achievement related to the irrigation efficiency is due to the management and infrastructure measures carried out by the trustees and part is due to the deficit irrigation in fields and gardens due to the physical shortage of water resources. So, the latter case is a serious threat to soil resources and it is necessary to proper measures to control salinity and further destruction of soil resources in the future.