Monitoring Recent Changes in Drought and Wetness in the Source Region of the Yellow River Basin, China

The source region of the Yellow River Basin (SRYRB) is not only sensitive to climate change and vulnerable ecological environment but also primary runoff generating (YRB). Its changes drought wetness profoundly impact water resources security, food production in middle downward reaches YRB. In context global warming, based on daily precipitation, maximum minimum temperature 12 national meteorological stations around within SRYRB during 1960–2015, this study obtained standardized precipitation index (SPI) reconnaissance (RDI) 1-, 3-, 6- 12-month scales, then compared consistency SPI RDI many aspects. Finally, temporal spatial variation characteristics 1960–2015 were analyzed study. results showed that have high different time scales (correlation coefficient above 0.92). According average distribution trend RDI, presented an overall state scales. We found increasing since early 1980s. terms events magnitudes, highest frequency for moderate severe ones was June (12.7%) February (5.5%), respectively, extreme events, both September January had (1.8%). Among four seasons, rate spring largest with a value 0.38 decade?1, followed by winter (0.36 decade?1) autumn (0.2 smallest summer (0.1 decade?1). There greater between values larger such as annual vegetation growing seasonal (VGS) SRYRB. generally VGS scale. These findings can provide data support management