Document Type : Research Paper
Authors
1 Former Grad. Student of Desert Management, Dept. of Natural Resources, Yazd University, Yazd
2 Assoc. Prof., Dept. of Natural Resources, Yazd University, Yazd
3 Assist Prof., National Salinity Research Center, Yazd
4 M.Sc., Center of Dry and Arid Zones, Yazd University, Yazd
5 Expert of Irrigation and Drainage, National Salinity Research Center, Yazd
Abstract
Today, water scarcity is one of the main problems around the world, especially in arid and semi arid regions. Iran is a country that is now faced with water scarcity. One of the effective solutions for water management in arid catchments is determination and analysis of water balance components. So this study has focused on determination of water balance components in arid-mountainous catchment of Manshad in Yazd province, during 2006-2007 cropping season. To estimate actual daily evapotranspiration (ETa) of the region, time series of MODIS images were acquired and used via the surface energy balance algorithm for land (SEBAL)methodology. Annual ETa then was calculated in the form of a pixel by pixel basis map. Also annual precipitation (P) and runoff (R) were calculated using rain gauge and hydrometric station records, respectively. Inaddition soil water storage of the catchment was estimated using double ring installation and infiltration rate measures. After determination of annual P and R, the ET component was calculated as the residual of water balance equation. Then the calculated ET was compared with the estimated ET of SEBAL methodology. Comparisons show the adequacy of SEBAL in estimation of actual ET at the studied condition. Finally, the results of the study show that a large portion of catchment available water wastes through evapotranspiration, nearly540 mm. The runoff and soil storage amounts of the studied year are about 117 and125 mm, respectively.
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