Changes of Flow Regime Variables Under the Influence Climatic Components of Precipitation and Temperature in Some Rivers of Sabalan Mountain

Water resources management needs to consider the effects of climate change on its main hydrologic cycle components. Therefore, the present study was conducted to analyze the impact of high and low flow variables from rainfall and temperature changes in the rivers of Sabalan in Ardabil Province. The rainfall and temperature gauge stations corresponding to hydrometric stations were selected. Then, the dependency of discharge and climatic components were examined during 1969 to 2019. The Change Point Analysis was used to test the significant changes in rainfall and temperature time series. Then, the discharge data were divided into periods before and after the change of climatic variables. For both periods, 41 variables of high and low indicators were calculated using RAP software. Based on the results in Lay, Nir and Pol-e-Soltani stations, the maximum flow discharge in the period after the change in climatic components has a decreasing trend compared to the before period. The trend of the average value of rising rate in most stations was decreasing. The number of zero days in Ahl-e-Iman and Pol-e-Soltani stations has increased by 201 and 947 percent in the post-effect period, respectively. The mean values ​​of the 3-day moving maximum in Ahl-e-Iman, Nir, Pol-e-Soltani and Viladaraq hydrometer stations decreased by 29.53%, 45.58%, 35.24% and 39.42%, respectively. In conclusion, the hydrological behavior of the stations has changed under the influence of precipitation and temperature components.