Effects of large-scale climate anomalies on trends in seasonal precipitation over the Loess Plateau of China from 1961 to 2016

The trends and cycles of seasonal precipitation at 77 stations over the Loess Plateau during the period of 1961-2016 were analysed in this study. The results indicate spatial differences in seasonal precipitation trends over the Loess Plateau from 1961 to 2016, suggesting that a decreasing trend in precipitation is found in most of the southern plateau in the spring and autumn, especially in Shaanxi Province. The changes in seasonal precipitation trends may indicate that there has been a shift in the seasonal hydrological cycle towards heavy spring precipitation and a much drier summer in the Loess Plateau. The magnitude of the downtrends means that regions with decreasing precipitation may become drier, which will exacerbate water scarcity in the region. The relationships between seasonal precipitation and large-scale climate anomalies indexes, including the western Pacific subtropical high index (WPSHI), the southern oscillation index (SOI) and the Pacific decadal oscillation (PDO), show that seasonal precipitation (except in the summer) over the Loess Plateau may be affected by ENSO, while summer precipitation in the southern and eastern is more are susceptible to the WPSH. Therefore, it will be better to predict trends in precipitation over the Loess Plateau with these relationships, which can provide valuable inputs to ecological restoration and water resource managers in these regions.