Hydrometeorological variation in the middle and upper reaches of the Yellow River Basin (1960–2019)

Abstract

The hydrological and meteorological elements of the Yellow River Basin have undergone fluctuations in response to both climate change and human activities. Understanding its evolutionary trends is essential for the development of effective water conservation measures. Employing linear fitting, Mann–Kendall, and wavelet analysis techniques, this study scrutinizes the trends and periodicity in precipitation, air temperature, and runoff within the middle and upper reaches of the Yellow River Basin from 1960 to 2019. The findings elucidate that temperatures in the middle and upper reaches of the Yellow River have been progressively increasing on an annual basis, while precipitation exhibits periodic fluctuations, and annual runoff demonstrates a declining trajectory. Sudden changes in runoff and temperature transpired in the years 1985 and 1997, respectively, whereas sudden changes in annual precipitation occurred in 1961 and 2012. On an annual scale, the influence of temperature and precipitation on runoff displays no evident prominent cycle. Notably, a significant negative correlation exists between temperature and runoff, with the noteworthy impact of temperature on runoff primarily manifesting in the 6-year sub-cycle spanning 1986 to 1992, as well as the 9-year sub-cycle encompassing 1963 to 1972. Conversely, precipitation and runoff exhibit a significant positive correlation. The substantial effect of precipitation on runoff is mainly concentrated within the 9-year sub-cycle from 1963 to 1972 and the 8-year sub-cycle from 1972 to 1980. Precipitation emerges as the primary driving force behind watershed runoff. In essence, the study's outcomes unveil the implications of climate change on runoff within the middle and upper reaches of the Yellow River Basin, thereby offering pertinent insights for effective water resource management strategies in the face of evolving climatic conditions.