Spatial and temporal variability of annual precipitation during 1961–2006 in Yellow River Basin, China

The Shannon Entropy method, Mann–Kendall method (M–K method) and linear fitted model were applied in this study to investigate the spatial and temporal patterns of trends of the precipitation in the Yellow River Basin (YRB) during 1960–2006. Results indicated that the precipitation possessed longitude zonality and had no clearly linear relationship with the latitude, it showed a decreasing trend in most of the precipitation stations, only two meteorological stations displayed upward trend in the YRB. The abrupt changes revealed by the M–K method mainly occurred to the south of 38 °N in the middle-lower reaches of the YRB. Furthermore, the abrupt changes occurred in the period ranged from 1963 to 1998 and the abrupt changes in the lower reaches appeared earlier than those in the middle and upper reaches of the YRB.