An estimation on wheat water irrigation in I.R of Iran

There are currently about 1.2 billion people, nearly a fifth of the global population faced to physical water scarcity, and 500 million by 2025 will be encountered to such status. Of these, 1.6 billion people, nearly a quarter of the world's population face economic water shortages. According to Iran's geographical position in semi-arid and dry region, and share of irrigated agriculture in water resources consumption, some researchers, policy makers and NGO's are thinking that national wheat production consume the bulk of the renewable water resources. So they propose some limitation for national wheat production. The main point of this article is to answer this question: What is the amount of water consumption trough the national wheat production in a crop year? To answer this question, ArcGIS , wheat production at 401 regional scale and wheat net irrigation information at 620 watershed scale are organized. Furthermore the farm system irrigation efficiencies are estimated by referring to water and agricultural expert's judgment. According to the results net water consumption for 9165176 tons irrigated wheat production is 8106.4 million m3, weighted average of farm irrigation system efficiencies is estimated 44.7 percent, so national water consumption for irrigated wheat national production is 18135.1 million m3, and according weighted average of wheat net irrigation trough the 620 water basin 2907.1 m3/h, it is estimated about 11628.02 million m3, green water was used for 4000006 tons dry land wheat production.