rangeland ecohydrology, new paradigm in water management of arid and semi-arid lands

at the beginning of twenty-first century, the water crisis in the priority policy andmanagement is inside and outside of the country as principle thoroughly human, social,economic and political rulers of the country is considered abundant. the world bank hasannounced that during 1960 and 2025, water resources in middle east, from 3430 m3 for theeach person in year reach to 667 m3 because of population growth, degradation of naturalresources, extent and spread of deserts. study of ecohydrology in arid and semi aridrangelands of the world is one of the newest methods for available water resourcemanagement. in this science, all of effective ecology elements on water balance equationwere reviewed. in these areas, a strong relation had been seen between ecology and hydrologyprocesses. in these areas, not only lack of precipitation, but also irregular and unpredictabledistribution of precipitation was problematic. ecohydrology pays particular attention to theseareas of vegetation and its impact on groundwater and surface water.