Optimal virtual water flows for improved food security in water-scarce countries

This is the final version. Available on open access from Nature Research via the DOI in this recordThe worsening water scarcity has imposed a significant stress on food production in many parts of the world. This stress becomes more critical when countries seek self-sufficiency. A literature review shows that food self-sufficiency has not been assessed as the main factor in determining the optimal cultivation patterns. However, food self-sufficiency is one of the main policies of these countries and requires the most attention and concentration. Previous works have focused on the virtual water trade to meet regional food demand and to calculate trade flows. The potential of the trade network can be exploited to improve the cropping pattern to ensure food and water security. To this end, and based on the research gaps mentioned, this study develops a method to link intra-country trade networks, food security, and total water footprints (WFs) to improve food security. The method is applied in Iran, a water-scarce country. The study shows that 781 × 106 m3 of water could be saved by creating a trade network. Results of the balanced trade network are input to a multi-objective optimization model to improve cropping patterns based on the objectives of achieving food security and preventing water crises. The method provides 400 management scenarios to improve cropping patterns considering 51 main crops in Iran. Results show a range of improvements in food security (19–45%) and a decrease in WFs (2–3%). The selected scenario for Iran would reduce the blue water footprint by 1207 × 106 m3, and reduce the cropland area by 19 × 103 ha. This methodology allows decision makers to develop policies that achieve food security under limited water resources in arid and semi-arid regions.Iran National Science FoundationCenter for International Scientific Studies and Collaboration (CISSC), Ministry of Science, Research and Technolog

Investigation of The Effect Hydraulic and Atmospheric Factors on the Evaporation and Wind Draft Losses in The Fixed Head Sprinkle Irrigation System

Correct understanding of the factors affecting the rate of evaporation l and wind draft losses on sprinkler irrigation systems is important in order to provide guidelines for the development and utilization of water resources. This study was performed to identify the factors affecting the rate of evaporation and wind draft losses and also equations presents for estimating of evaporation and wind draft losses on the fixed head sprinkler irrigation systems, under various conditions of hydraulic and atmospheric. In this study sprinklers of ZK30, ZM22 and AMBO was used. The tests were carried out at the University of Kurdistan research farm located in the village of Doshan with single sprinkler method Accordance with the ISO 7749-1 and ISIRI 8995-3 standards. Evaporation and wind draft Losses were measured at different applied pressures under various conditions of atmospheric. The results showed that parameters of vapor pressure deficit and temperatures had the highest correlation with evaporation and wind draft losses in all three types of sprinklers, and this correlation is significant at the 1% probability level. Also results showed that the correlation between wind velocity and losses is in sprinklers of ZM22 and ZK30 significant at the 1% and 5% probability level respectively and in the sprinkler AMBO is no significant correlation. In overall evaporation and wind draft losses increase to 9.4 percent by increasing of 1 meter per second of wind velocity