Temporal and spatial variability in precipitation trends in the Southeast Tibetan Plateau during 1961–2012

Abstract. Using the monthly precipitation data at 14 stations from 1961 to 2012, the precipitation trends at the seasonal and annual scales are analyzed using the Mann–Kendall test in the Southeast Tibetan Plateau (STP). The area-averaged precipitation shows an increasing trend in the STP with strong temporal and spatial variations. The seasonal and annual precipitation increased, except in the summer; the annual precipitation increased by about one millimeter pre year over the last 52 years. The spring precipitation significantly increased at the 99% confidence level, while the mean summer precipitation insignificantly decreased at the 95% confidence level. The extreme precipitation, including the maxima and minima, also experienced overall increases. More than 78% of the stations exhibited increases in the annual precipitation (93% in spring). The precipitation variation with elevation was not obvious, but the variation with complex topography was obvious in the STP. The largest precipitation increases and decreases occurred in high-precipitation areas, while the increasing precipitation was dominant in or near the main area of the Tibetan Plateau (TP). The results of this study reveal the spatio-temporal variability in the precipitation trends in the STP for the first time. The results are beneficial for understanding the local climate characteristics in the STP and in the entire TP.