The Modeling of Future Precipitation Changes, under Climate Change in the Southern Coasts of Caspian Sea.

Introduction and Background: Precipitation is the most important parameter affecting various aspects of social, economic and natural resources. A study of future changes in rainfall is possible through the prediction of climate models. In the present study, future changes in the rainfall of the southern coasts were investigated for proper planning in the southern coast of the Caspian Sea. The future precipitation of selected stations in the southern shores of the Caspian Sea using the LARS-WG model and observations of precipitation data during the base period and using climatic fluctuations derived from the HadCM3 general circulation model under the scenarios A2, B1 and A1B during the period was modeled in the period between 2011-2039. Results showed that simulated rainfall has a high correlation with observational precipitation in the base period. Based on the MBE and MAE criteria, the error rates obtained for simulated precipitation during the base period are high in the fall season. According to the results, the model of rainfall changes in southern shores in the following period was drawn using scenarios A2, B1 and A1B, according to which the rainfall will increase in all stations of the region. The percentage of precipitation increase in stations Anzali, Astara, Babolsar, Gorgan, Noshahr, Ramsar and Rasht based on scenario A2 will 0.3, 7.9, 2. 2, 1.4, 8.7, 0.8 , 7.6%, and based on the A1B scenario, 9.3%, 12.12%, 12.4%, 4.7%, 13.9%, respectively and based on the B1 scenario will be 8.7, 9.7, 6, 5/11, 7/3, 3/5, 6/13 percent.