关键词: 降水, 时空变化, 太阳黑子, 长江源, 澜沧江源, 黄河源, 柴达木盆地, 青海省

Abstract: According to the monthly precipitation data from 50 meteorological stations in Qinghai Province during 1965-2018 and sunspot data over the same period, the spatial-temporal features of precipitation in Qinghai Province were analyzed with methods of precipitation concentration degree (PCD) and concentration period (PCP), linear trend, M-K test and Morlet wavelet analysis. Qinghai Province was divided into the Yangtze River and Lancang River source area, Yellow River source area, eastern low altitude area and Qaidam Basin area. Results unveiled a spatially increasing trend of precipitation in Qinghai from the northwest to the southeast. In terms of inter-annual variation, the annual precipitation in Qinghai grew by 0.81 mm per year, and its four sub-areas also showed upward trends. In monthly scale, however, the precipitation distributed unevenly during a year and the PCD tended to be uniform gradually. A weak abrupt change of precipitation was observed: the abrupt change in Qinghai Province and its eastern low-elevation area happened in 2006, the Yangtze River & Lancang River source area in 2003, and the Qaidam Basin around 2001; four possible abrupt change points in the Yellow River source area were observed. Wavelet analysis indicated that the precipitation on Qaidam Basin had a significant period of 22-23 years, and the Qinghai Province and its other three subareas 28-30 years. On a period of 28 years, the wavelet coefficients of the relative numbers of the precipitation in Qinghai Province and its four subarea and sunspot all reached positive correlations of 0.95, 0.86, 0.91, 0.93, and 0.75, with their significance reaching 0.01.

Key words: precipitation, spatio-temporal variation, sunspot, Yangtze River source area, Lancang River source area, Yellow River source area, Qaidam Basin, Qinghai Province