Assessing the Impacts of Changing Irrigation System on Water Productivity in Doroudzan Irrigation and Drainage Network

Doroudzan Irrigation and Drainage Network (DIDN) plays an important role in the production of agricultural products in Fars province of Iran, but it has faced serious problems due to low precipitations and indiscriminate water extraction. Considering the importance of estimating the amount of water consumption productivity for water resources management, this study aimed at calculating the agricultural water productivity in the DIDN network using Crop per Drop (CPD) Index, and to investigate the effects of the change in the irrigation system "from surface to pressurized" on the variables in the productivity index, the assessment model of Soil, Water, Atmosphere and Plant (SWAT) was used in 2013-2014 cropping year. The study findings showed that in the DIDN network, the CPD in terms of the sum of irrigation water and effective precipitation (CPDIP) is equal to 0.606 kg per cubic meter. In addition, based on the study results, changing the irrigation system from surface to rainwater can lead to an increase in the productivity index in terms of actual evaporation and transpiration (CDPET) and CPDIP index by 23 and 46 percent, respectively. Therefore, it can be said that one of the important measures in order to improve the efficiency of agricultural water consumption in the Doroudzan Irrigation and Drainage Network (DIDN) is the development of pressurized irrigation system.