Precipitation changes in the mid-latitudes of the Chinese mainland during 1960-2014

Based on daily precipitation data from 163 meteorological stations, this study investigated precipitation changes in the mid-latitudes of the Chinese mainland (MCM) during 1960-2014 using the climatic trend coefficient, least-squared regression analysis, and a non-parametric Mann-Kendall test. According to the effects of the East Asian summer monsoon on the MCM and the climatic trend coefficient of annual precipitation during 1960-2014, we divided the MCM into the western MCM and eastern MCM. The western MCM was further divided into the western MCM1 and western MCM2 in terms of the effects of the East Asian summer monsoon. The main results were as follows: (1) During the last four decades of the 20th century, the area-averaged annual precipitation presented a significant increasing trend in the western MCM, but there was a slight decreasing trend in the eastern MCM, where a seesaw pattern was apparent. However, in the 21st century, the area-averaged annual precipitation displayed a significant increasing trend in both the western and eastern MCM. (2) The trend in area-averaged seasonal precipitation during 1960-2014 in the western MCM was consistent with that in the eastern MCM in winter and spring. However, the trend in area-averaged summer precipitation during 1960-2014 displayed a seesaw pattern between the western and eastern MCM. (3) On an annual basis, both the trend in rainstorms and heavy rain displayed a seesaw pattern between the western and eastern MCM. (4) The precipitation intensity in rainstorms, heavy rain, and moderate rain made a greater contribution to changes in the total precipitation than precipitation frequency. The results of this study will improve our understanding of the trends and differences in precipitation changes in different areas of the MCM. This is not only useful for the management and mitigation of flood disasters, but is also beneficial to the protection of water resources across the MCM.