Investigating and Analyzing the Rebound Effect Phenomenon of Irrigation Post Modernization and Necessary Considerations

The goals of irrigation modernization are mainly focused on increasing irrigation efficiency, improving water productivity, and ultimately reducing irrigation water consumption and saving scarce water resources in these countries. Meanwhile, various studies have shown that increasing irrigation efficiency and improving water productivity through the development of the use of efficient and modern irrigation systems, sometimes did not lead to real savings and reduction of agricultural water consumption as expected or vice versa, it has caused its increase. This phenomenon is called "rebound effect” of water. The concept of the rebound effect phenomenon is that with the use of efficient irrigation technologies, irrigation efficiency and water productivity increase, but part or all of the expected saved water may be offset by more water consumption. The effective factors and reasons for the rebound effect phenomenon are mainly: the increase in the irrigated area following the reduction of water consumption, the increase in evapotranspiration due to the change in the cropping pattern and increased crop yield, reduction in the quantity and quality of return flows due to increased irrigation efficiency, deficit irrigation to provide enough water for the increased cultivated area. In general, there is a need to mainstream the literature on the subject and following determining the extent of rebound effect and the necessary analysis, relevant hints to the policy makers and those responsible for the development of new irrigation technologies should be given to adopt a suitable policy and to take actions to implement technical, economic-social and political solutions.