A. R. NEJADMOHAMMAD NAMAGHI - Hasheminejad High Education Center, Khorasan Razavi, Mashhad, Iran
Z GHOLIZADE

There are some experimental formulas to estimate the water budget in basins. Precipitation and temperature are the principle factors which these formulas have been based on them. Since all of these formulas have been prepared and calibrated for a special regions, sometimes in the same regions application of two different formulas, displays different answers. Moreover, in arid lands errors in estimation of water budget will take place because of different precipitation and temperature. Therefore, in this research, TURC and COUTANGE formulas were selected and their accuracy was tested by some changes in the method of application of these formulas (Modified Experimental Formula) in TORBATEJAM basins. Hence the selected basins were divided through a network and these formulas were separately in every pixel. Again by using of hypsometric map of basins these formulas were tested in each of the hypsometric strip. Finally it was known that between TURC and COUTANGE formulas, the grid and strip methods of TURC formula "Modified Experimental Formula" (MEF), are the best methods for estimating of water budget in arid regions and there is significant different between MEF and other classical formulas (TURC and COUTANGE).

water budget, arid lands, MEF TURC. MEF COUTANGE