Analysis the variability and trends of precipitation during 1959–2008 in Northwestern, China

Northwestern China has one of the most complex climates due to the complex terrain and complex climate change in China. The environment there is sensitive to the regional climate change, and is also very vulnerable to the global climate change. The present study examines the spatial and temporal variability and trends of precipitation during 1959-2008 in Northwestern China. The methods used include the climate trends coefficient and climate trends. The variability of precipitation is regionally different. It is significantly increasing trends of precipitation in western and middle, however decreasing trends in eastern in northwestern China. The monthly trends of precipitation is different to seasonal precipitation and annual precipitation. However the spring, the summer and the fall trends of precipitation are accordant to trends of annual precipitation.