Research on the evolution characteristics of future climate change in West Liao River Basin

In order to explore the characteristics of climate change in the future in the West Liao River Basin under the background of future climate change, this study analyzed the changes of the annual average temperature, annual precipitation, and annual evapotranspiration from 2021 to 2060 in the West Liao River Basin under the scenarios of RCP4.5 (low emission) and RCP8.5 (high emission) originated from Intergovernmental Panel on Climate Change's Fifth Assessment Report. The results show that (1) under the two different scenarios (RCP4.5 and RCP8.5), the annual average temperature in the West Liao River Basin is 7.67 degrees C and 8.12 degrees C, respectively, and the temperature shows an upward trend; the mutation years of RCP4.5 are more than those of RCP8.5; the annual average temperature of RCP4.5 is controlled by periods of 22 years and 29 years, while RCP8.5 has only one main period of 29 years; the contribution rates of the first eigenvector variance of EOF are 97.12% and 96.64%, respectively, and the change types are the same. The sensitive areas of variation are in the southwest and western regions respectively. (2) The annual precipitation in the West Liao River Basin under the two scenarios are 815.78mm and 798.64mm, with tendency rates of -20.51/mm/10a and 17.26/mm/10a; the mutation years in the West Liao River Basin under scenario RCP4.5 are mostly occurred in the 2030s and 2040s, while those under scenario RCP8.5 are mostly occurred in 2040s and 2050s; under scenario RCP4.5, the change is mainly controlled by shorter periods, while under scenario RCP8.5, the change is controlled by two main longer periods of 19 years and 28 years. Under the two scenarios of RCP4.5 and RCP8.5, the cumulative contribution rates of the variance of the first three eigenvectors of the EOF in the West Liao River Basin are 42% and 90.23% respectively. The first eigenvector is consistent, and the second and third eigenvectors are the reverse type of South (East)-North (West). (3) The results show that the annual evapotranspiration in the West Liao River Basin under the scenarios of RCP4.5 and RCP8.5 is 597.79mm and 618.45mm, respectively, and the trend rates are 18.20/mm/10a and 4.48/mm/10a; under scenario RCP4.5, the change is controlled by periods of 23 years and 29 years, while under scenarios RCP8.5, the change is controlled by periods of 18 years and 28 years; the contribution rates of the first eigenvector variance of EOF are 91.05% and 89.51% respectively, and they are consistent distribution, and their sensitive areas are in the southeast and central regions respectively.