The effect of climate change on stream flow used Statistical downscaling of HADCM3 model and Artificial Neural Networks

In the wake of the damage that man has Sntgrayyash the ground , place the study of climate change and global warming , due to the industrialization of the earth , the day will be added .The radiative effect of greenhouse gases on global warming is a major factor and the factor in global climate change with unprecedented speed . Every kind of climate change on the terrestrial earth is the beginning a chain of reactions whose direct effect on hydrological processes can be observed.
In this study, SDSM model is used to measure the large -scale data of the atmospheric general circulation model (HadCM3) in two local climate change scenarios, A2 and B2, for the meteorological parameters of temperature and precipitation in the basin of Qara Su. Then, considering the data of rainfall, temperature and flow rate and the fine- scale model outputs exponentially in the an artificial neural network is used to calculate the river’s discharge during the future period. Climate model results indicate an increase in temperature and a decrease in rainfall within the desired course relative to the base period. Consequently, this increase in temperature and decrease in rainfall will lessen the discharge rates of Qara Su River.