Water Security Assessment in Arid Climates Based on Water Footprnt Concept

South Khorasan province، with an average annual rainfall of 180 to 200 mm، Average annual production of over 490 thousand tons of agricultural products، overdraft more than 138 million cubic from groundwater، takes place so of 24 Prairie Independent State، 13 Plains Forbidden، 2 Plains critical prohibited، 3 Plains proposed ban. In this study، the average virtual water crops in South Khorasan Province was about 1312 cubic meters per ton of product and agricultural water use efficiency is 0. 62 kgm3. As a result، rice imported about 7. 76 million cubic meters of water in virtual form due to agricultural product trade in 2008 to 2012. During this period، the largest volume of virtual water export was tomato sauce، potato and apple which declined from 24. 5 to 17. 2 million cubic meters. In 2012، the net water requirement in potential condition for food security of 662،534 populations was about 723 million cubic meters. To achieve food security، requires about 448 thousand tons of food supplies، taking into account the actual conditions and efficiencies of 35%; we need about 2065 million cubic meters of water to form a virtual. The water footprint of province was 1142 million cubic meters or 1723. 7 cubic meters per capita per year.