In this research, to anticipate the effects of climate change on the precipitation of selected stations in East Azerbaijan province, including Ahar, Maragheh, Mianeh, Jolfa, Sarab, and Tabriz stations, which had 29-year common statistical data from 1985 to 2014, with The use of LARS-WG6 model were studied. In this research, the effectiveness of the LARW-WG model for generating and simulating daily data of temperature, precipitation, and sunshine hours in the study area was investigated using the statistical parameters R2, MAE, and RMSE. The results showed that at the confidence level of 99%. There is no significant percentage difference between the real data and the data obtained from the model, and the model has the necessary efficiency to generate daily data, therefore, after ensuring the model's ability, using HadGEM2 atmospheric general circulation model under RCP 2.6 scenarios, RCP 4.5 and RCP 8.5 in the next two periods from 2021 to 2040 were forecasted for the rainfall changes in the studied area. The results of forecasting the average annual rainfall changes of the studied stations of East Azerbaijan province in the statistical period of 2021-2040 showed that According to RCP 2.6, precipitation will increase in all the studied stations in the next 20 years, but according to RCP4.5 and RCP8.5, we will see an increase in precipitation only in Jolfa station, and in the rest of the studied stations, precipitation will increase by will be significantly reduced.
Climate change is one of the most important and complex concerns of the current and future centuries. The dangerous effects of climate change on human life will cover almost all aspects of life. Drought, rising sea levels, violent storms, reduction of freshwater resources, warming of the air, forest fires, and desertification are among these effects (Mohammadi et al., 1400). Climate change is one of the most important ecological problems of the 21st century. According to the fifth report of the Intergovernmental Panel on Climate Change, these global changes are most likely caused by human factors. Various studies show that this phenomenon can have negative effects on various systems of water resources, agriculture, the environment, industry, and the economy. Forecasting the quantity and quality of climatic changes is one of the complex issues that have occupied the minds of climatologists. Now, with the help of obtaining new technologies and possessing multiple series of necessary data of climatic variables and with the help of knowledge to understand the relationships between these variables, basic steps have emerged in understanding and predicting climatic trends, in such a way that now Computer models all respond to climate forecasting issues and factors affecting climate change within their capabilities (Darvand et al., 1400). Currently, the most reliable and developed tool for investigating climate change and its impacts is the 3D Ocean–Atmosphere General Circulation Model (AOGCM). The AOGCM model is based on physical laws. These relationships are resolved in a three-dimensional network around the world. The presented models show climate parameters in the future (until 2099) for different emission periods. By using these methods with different climatic variables, the effects of climate change on the variability and adaptation of plants can be investigated.
The research method in this study relies on the LARS WG model. After sorting, processing data, and preparing input files, finally, the model studied in this research was finally implemented for the basic course. In the next step, using the mean absolute error (MAE), coefficient of determination (R2), and the root mean square error (RMSE) to evaluate the data generated from this model and the real data available in the basic period became After checking the results of the confidence stage and evaluating the capability of the LARS-WG model for simulating meteorological data by considering the low values of the error measurement indices and the high values of the calculated coefficient of determination, the new version of LARS WG6 was used in this research. The required data including minimum temperature, maximum temperature, precipitation, and sunshine hours are collected from the synoptic station of East Azarbaijan province and given as input to the model. The data simulated by the CMIP5 atmospheric general circulation model is related to the period 2021-2040, which under the scenarios of RCP 2.6, RCP 4.5, and RCP 8.5 by the LARS-WG model compared to the base period 2014-1985 in the scale of the studied stations. In order to reduce the uncertainty of the average of the calculated profiles for the above model, it has been obtained. In the current research, it has given appropriate and favorable results regarding the study of the effects of climate change scenarios on the precipitation of East Azarbaijan province in the direction of microscale. CMIP5 models are used in LARS-WG6 software, which is one of the most famous and important models for generating random weather data. This model is used to generate the values of precipitation, maximum temperature, minimum temperature, and sunshine hour in a station, regarding the basic climate conditions as well as the future. For this reason, the study has been done on various stations of the studied area. The daily temperature and precipitation data of 6 stations of East Azarbaijan Province, including Jolfa, Ahar, Sarab, Tabriz, Mianeh, and Maragheh stations, were used for exponential micro-scale as well as temperature and precipitation forecasting during recent years. Then, in the present research, to implement the model, first, taking the 29-year period from 1364 to 1393 (1985-2014) as the base period, the necessary data, including precipitation, minimum and maximum temperature, and sunshine hours, were obtained from the National Meteorological Organization.
The results of forecasting changes in the average annual precipitation of the studied stations of East Azerbaijan Province in the statistical period of 2021-2040 showed that according to RCP 2.6, the precipitation will increase in all the studied stations during the next 20 years, but according to RCP 4.5 and In RCP8.5, we will see an increase in rainfall only in Jolfa station, and in the rest of the studied stations, rainfall will decrease significantly.
Keywords
Climate changes, HadGEM2 model, RCP 2.6, RCP 4.5 and 8.5 RCP scenarios, East Azerbaijan province.