Variability and prediction of climatic elements in the Three Gorges Reservoir

Abstract

Climate change is one of the major global issues commonly concerned by international communities. This study takes the Three Gorges Reservoir as an example, based on the observed meteorological data at Yichang station selected as the representative station of local climate, attempts to evaluate the variability of climatic elements during past 49 years (1961–2009) and predict the evolution trends of precipitation and temperature in the future 30 years (2021–2050) under climate change. Specifically, the temporal variations and sudden changes of precipitation, temperature, relative humidity and sunshine hours during past 49 years in the Three Gorges Reservoir are analyzed combining moving-average and linear regression with Mann-Kendall method, and the precipitation and temperature data in the future 30 years are obtained from the average dataset of 20 global climate models using REA (Reliability Ensemble Averaging) method and a statistical downscaling model. The results indicate that: 1) during 1961–2009, the precipitation slightly increased and the estimated sudden change time was 1963, the temperature significantly increased and the estimated sudden change time was 1975, the relative humidity significantly decreased and the estimated sudden change time was 1962, the sunshine hours significantly decreased but there was no sudden change time estimated; 2) during 2021–2050, the precipitation will slightly decrease by about 0.8%, and the scale of extreme events will reduce, the temperature will increase by about 1.3°C, and the extent of minimum increase is larger than that of maximum.