نوع مقاله : مقاله پژوهشی
دانشیار گروه مهندسی آب، دانشگاه زابل، زابل، ایران
عنوان مقاله [English]
Improper wheat production and consumption pattern, which is the most important product in global food basket, has a significant role in the occurrence of the current water challenges, especially within the arid and semi-arid regions of the world. In this research, along with diagnosing and analyzing current challenges through wheat production and consumption in Iran, new opportunities for modifying current problems as well as the quantitative results of the proposed management scenarios were presented. Over a 31-year period during 1980-2010, blue, green and grey water footprints (WF) related to wheat production and consumption, and consequently, virtual water balance related to interregional and international wheat trades were estimated. All calculations were carried out at the provincial scale, and base on official statistics published by national and international organizations. Based on the national average, the contribution of blue water in wheat WF increased by 73.4% as a consequence of 43% reduction in the share of green water. For N-fertilizers applied for producing a unit of wheat, 1727 m3 water is required to assimilated nitrogen loads to freshwater bodies beyond the standard level of 3.1 mg l-1, which is 1.2 times higher than one requires for assimilating surplus P. Despite of an overall reduction in total WF related to wheat consumption in 2010, the share of blue water in total increased by 21%. With a 142% increase, the overall interregional virtual water trade of wheat got 9.64 billion m3 in 2010, with 3.92 billion m3 blue water, 21% more than one in 1980. Under current condition, there is not enough water capacity in 8 provinces to carry out pollutants loads to freshwater bodies from lands under wheat. Besides, WF related to wheat consumption in 5 provinces, and WF related to wheat production in 3 provinces is higher than available renewable water resources. Based on water pollutant level and water scarcity level indices, the arid and semi-arid regions need to be of priority when implementing adaptation solutions. In addition to the highlighted influence of adapting proper methods for moderating wheat production pattern through improving water and yield productivities, moderating wheat consumption pattern will also have a considerable role in alleviating current challenges. Wheat waste resulted in 0.87 and 1.6 billion m3 water waste, respectively, in 1980 and 2010. In these years, the surplus pollution loads to water systems as a result of wheat waste were, respectively, 0.75 and 1.63 billion m3. Also, moderating interregional wheat trade based on WF index, aiming at increase wheat export from water abundant regions to the water scarce one, may result in up to 4.36 billion m3 water saving. In addition, expanding international wheat trade domain and selecting trading partners among those with lower wheat WFs may lead to 0.1-21.4 times lower pressure on global blue water resources. Based on the results, it could be concluded that implementing proper policies helps with achieving sustainable environment in both producing and consuming regions.