Mahdi Zarei - PhD in Natural Resources Engineering-Combating Desertification
Khodayar Abdollahi - Assistant Professor, Faculty of Earth Sciences, Shahrekord University
Mohammad Javad Mahdavi Lasibi - Department of Agricultural Sciences, Payame Noor University, Tehran Iran

Estimation of water balance component, both over space and time, is a key factor for a long-term water resources planning, especially in arid and semi-arid regions. The main objective of this is to assess the water balance component (groundwater recharge, surface runoff and evapotranspiration) in the Mashhad basin in different land-use types. To achieve this goal we applied a spatially distributed water balance model (WetSpass-M). Distributed land-use map, groundwater depth, monthly climatological data (e.g. precipitation, temperature…..), monthly LAI, slope and soil texture maps are the basic relevant input data for the model. All inputs were prepared in the form of digital maps using GIS and remote sensing tools. Resulting to the high evapotranspiration rate, high surface runoff and temperature, agricultural regions (including rain-fed and irrigation farming) has the lowest recharge from rainfall to groundwater system. Rangeland and residential land-use types have the lowest and highest surface runoff respectively, rangeland land-use has also the highest groundwater recharge in the study area.

Water balance, WetSpass-M, land-use, GIS, Remote Sensing, Mashhad Basin