Hydrological modeling of Climate Changes Impact on flow discharge in Haraz River Basin

In this research was assessed the climate change in 2011-2030 periods with A2 emission scenario by using of AOMCM models and uncertainty related that for this purpose were utilized of 6 models in Rineh and Baladeh stations. Climate change is effective on, river flow shortages, floods, and the declining water system that with predicting the climate change can perform fair management of water resources. The Haraz Watershed with 4012 square kilometer area is located in Mazandaran Province. To assess the impact of these changes on the watershed outlet, SWAT hydrological model was used. This model is sensitive to changes in terrain and weather. The time horizon 2000-2014 was used in order for calibration and validation the model. Then, after ensuring the performance of the SWAT model, the downscaled climate change data were determined by the study models for each climate factors input to SWAT model runoff change in future periods were assessed. The climate model results showed that the annual minimum and maximum temperature will be increased 0.7 ° C and 0.62 respectively. The average annual rainfall for the study area will be decreased at a rate of 18 percent. Compare current flow simulation showed that the peak flow for the future period will increase nevertheless the average flow discharge will decrease in the amount of 12 percent. Therefore the climate change should be considered in order to tackle with environmental hazards and Long-term planning.