Change trends of temperature and precipitation in the Loess Plateau Region of China, 1961-2010

The Loess Plateau is the most severe soil and water loss area in the world. The changing trends of annual mean temperature and annual precipitation over the last 50 years in the Loess Plateau Region (LPR) are investigated using observed time series from all available stations. The trends are assessed for both the entire LPR and its five integrated management divisions using the gridded data. It is shown that the region-averaged annual mean temperature has significantly increased over the last 50 years (1.91 degrees C/50 yr), whereas the region-averaged annual precipitation shows a non-significant negative trend (-29.11 mm/50 yr). Spatially, there is an enhanced warming gradient but an obvious drying to weak wetting gradient from the southeast to the northwest across the region. On divisional scales, a significant warming trend is detected for all the divisions. A significant drying trend and a nearly significant drying trend are found for the first and second divisions, respectively, and a non-significant positive trend for other divisions. Therefore the region can be divided into the southeast warming and drying sub-region (SESR) and the northwest warming and weak wetting sub-region (NWSR). Further analysis shows that the SESR has a significant warming trend (1.71 degrees C/50 yr) and a significant drying trend (-47.62 mm/50 yr), and the NWSR has a significant warming trend (2.25 degrees C/50 yr) but a non-significant wetting trend (1520 mm/50 yr). These results may have important implication in addressing the challenge of climate change in terms of the integrated management of the LPR. (C) 2012 Elsevier B.V. All rights reserved.