Abstract: Based on the 1960-2010 precipitation data from 12 meteorological stations in the Three-River headwaters region, and by the methods of climatic linear regression, 5-year moving average, inverse distance weighted (IDW) interpolation, Morlet wavelet analysis, and rescaled range analysis, this paper analyzed the spatiotemporal variations of precipitation and its future tendency in this region. In 1960-2010, the annual precipitation in this region presented an overall increasing trend, being lower in the 1960s, 1970s, and 1990s, obviously higher in the 1980s, and markedly increased after 2000. The precipitation in spring, summer, and winter, especially in spring, exhibited an increasing trend, but that in autumn had a decreasing trend. The variation trend of the precipitation in different catchments was not the same in four seasons. In most areas of this region, the precipitation had an increasing trend, being higher in the north and lower in the south, but less difference in the east and west. The precipitation in different catchments had different vibration periods during a certain time series. A similar variation trend was observed in the annual and seasonal precipitation in the region between the past and the future, but the continual strength of the precipitation somewhat differed with the catchments.

Key words: loess hilly region, soil moisture, inter-row system, seasonal drought.