Integrated assessment of variation characteristics and driving forces in precipitation and temperature under climate change: A case study of Upper Yellow River basin, China

In this study, an improved integrated framework (Distribution-Evolution-Equilibrium, abbreviated as DEE) was developed to analyze the spatiotemporal characteristics of climate change, in which the precipitation (Pr) and temperature (Te) were selected as typical elements. The DEE framework is dedicated to not only making clear the distribution and evolution (i.e., tendency, mutability and periodicity) features of climate change, but also determining its temporal concentration and spatial equilibrium patterns. Then, a case study was conducted in the Upper Yellow River basin (UYRB), China. Furthermore, the response relationship between the Southern Oscillation Index (SOI), Pacific Decadal Oscillation (PDO), Arctic Oscillation (AO), Sunspot (SN) and Pr, Te also were explored. Results reveal that: a) the Pr and Te generally present an upward trend in various degrees, while their high-value centers are distributed independently in space, with almost no duplication; b) there are abrupt variations in climate change, especially in the 1980s and 1990s, meanwhile the climate elements all have multi-period variation characteristics; c) the Pr and Te have relatively even distribution throughout the year, and the equilibrium state has been maintained at an ideal level and its degree generally remains within 0.4–0.7; d) AO and SN have more significant impact on climate change than SOI and PDO in the UYRB, but they are mainly locally correlated. Findings can provide reference to climatic disaster prevention, regional high-quality development, and ecological civilization construction.