Evaluating Impacts of Irrigation and Drought on River, Groundwater and a Terminal Wetland in the Zayanderud Basin, Iran

摘要: The Zayanderud Basin is an important agricultural area in central Iran. In the Basin, irrigation consumes more than 90 percent of water used, which threatens both downstream historical city Isfahan and Gavkhuni Wetland reserve—the final recipient river water. To analyze impacts land use changes occurrence metrological hydrological drought, we used groundwater data from 30 wells, standardized precipitation index (SPI) streamflow drought (SDI). Changes wetland were analyzed using normalized difference (NDWI) values mass depletion was also assessed with gravity recovery climate experiment (GRACE)-derived data. results show that 45 out studied 50 years, can be considered as normal respect to mean amount, but droughts exist half recorded years. increased after 1970s when large schemes introduced. recent decades, flow rate reached zero part River. NDWI confirmed severe drying on several occasions, compared situ estimated (±5) mm annually; exploitation has average 365 Mm3 annually, a constant annual drop 1 2.5 meters level annually. demonstrate connection between surface resources management highlight repeated River are directly related human activities. assess sustainability Basin.