Probabilistic Assessment of Climate Change on the Hydrology of the Aidoghmoush River, East Azarbaijan, I.R. Iran

A new probabilistic approach was adapted to the negative impact of climate on stream flow. To generate climate change scenarios in the future under the A2 emission scenario، the HadCM3 model was employed. By introducing climatic variable time series in future periods to the IHACRES hydrologic model، long-term stream flow simulation scenarios were produced. By fitting statistically different distributions on the runoff produced by using a goodness-of-fit test، the most appropriate statistical distribution for each month was chosen and relevant statistical parameters were extracted and compared with statistical parameters of the runoff in the base period. Results show that the long-term annual runoff average in the three future periods compared to the base period. Despite the reduction in the total runoff volume in the future periods will decrease compared to the baseline period، the decrease is related to the medium and high flows. In low flows، the total runoff volume for future periods compared to the baseline period will increase 47، 41، and 14%، respectively. To further assess the impact of annual average runoff on flows، it is necessary to examine correlation of time series using the stream flow transition probability. To compare the stream flow transmission probability in each of the future periods with base period stream flow in each month، stream flow was discretized and performance criteria were used. This approach was adapted for the Aidoghmoush River، East Azerbaijan. Results indicated a low coefficient of correlation and a high error indicator.