In 2023, the central part of the Hexi Corridor experienced an extreme high temperature and drought that would occur once every 60 years, which adversely affected local agricultural production and ecological environment, causing serious economic losses. This study uses various observational datasets to discuss the characteristics and effects of the high-temperature and drought in the central Hexi Corridor in 2023 from perspectives of meteorology, hydrology, ecology and agriculture. We further examine the responses of summer precipitation in the central Hexi Corridor to anomalous atmospheric circulation and sea surface temperature (SST). The datasets used in this study include monthly precipitation and temperature data during 1951—2023 from six national basic stations in the central Hexi Corridor, the Heihe river runoff data from Yingluoxia hydrological station in the upper reaches of the Heihe river, the FY-3D/MERSI satellite data, the GF-1 satellite data, and the NCEP/NCAR monthly mean reanalysis data, and 88 atmospheric circulation indexes and 26 SST indexes provided by National Climate Centre. The results show that precipitation and average temperature in the central part of the Hexi Corridor from May to September 2023 both exceeded historical extremes, with precipitation reached a new historical low and temperature reached a new historical high. The combined effect of high temperature and low precipitation significantly exacerbated the intensity of drought. In the middle Qilian mountains, the average snow cover area decreased by 45.8%, the annual runoff decreased by 15%, the main reservoir area decreased by 25.8%—66.0%. The characteristics of drought spread are meteorological drought—hydrological drought—ecological and agricultural drought. We find that precipitation in the central Hexi Corridor from May to September had significant multi-scale oscillations in 5, 11, 17 and 32 a, and multiple time scales showed that 2023 was in a period of less oscillation. When the drought in the central Hexi Corridor was observed, the atmospheric circulation anomalies included a southward shifted ridge line of the western Pacific subtropical high, an eastward shifted ridge point of the western extension, a westward shifted ridge point of the South Asian high pressure, a weaker than normal Indian low, a smaller polar vortex area in the northern hemisphere and Asia, a stronger blocking high in the middle and high latitudes of Asia, and increased longitudinal coverage of the westerly circulation in Eurasia. Meanwhile, positive SST anomalies occurred in the Nino3 area and the west wind drift region, while negative SST anomalies occurred in the Kuroshio region.

Arid and semi-arid regions constitute approximately one-third of the total land area in China and are vulnerable to the effects of global climate change. Over the past century, a large number of studies have investigated regional climate change and its impacts. However, the conclusions are inconsistent due to differing research perspectives, and this has highlighted the urgent need to obtain systematic, scientific knowledge through review and synthesis. This study, based on a survey of all available literature, reviews the evolution of regional climate change and its effects in the arid and semi-arid regions of China over the last century. The present review examines three aspects of the surveyed previous studies: Data, methods, and subjects, and then summarizes essential scientific findings into four subject areas: The origin and expansion of arid and semi-arid regions, the characteristics of climate change in these areas, the drivers of climate change in arid and semi-arid zones, and the consequences of climate change in such environments. Finally, six key directions for future research on climate change and its effects on the arid and semi-arid regions of China are proposed.

Under the background of climate warming, the frequency and intensity of droughts are increasing. The regularity of drought occurrence and the complexity of its formation mechanism are becoming more prominent, which poses new challenges to the mechanism study on drought formation, the theory and method of drought prediction and changes in disaster risk. They also restrict improvements on current drought prediction, early warning, disaster prevention and control ability. In recent years, with the support of several national projects such as the National Key Basic Research and Development Program (973 Program), a series of new achievements have been made in the studies of formation mechanism, prediction theory and risk characteristics of drought disaster. This paper systematically summarizes recent progress in the following aspects: (1) Clarified the mechanism of Qinghai-Xizang plateau heating, sea temperature, summer monsoon, remote correlation and other factors on the formation of drought. (2) Found the sensitivity of crops at different growth stages and temporal drought scale to precipitation deficit. (3) Revealed new characteristics of drought disaster risk distribution and variation in typical regions under the background of warming, and constructed a new conceptual model of drought disaster risk. (4) Developed the integrated forecast system of seasonal and sub-seasonal drought in East Asian monsoon area. On the basis of summarizing the existing research results, future research on drought formation mechanism and disaster risk is proposed, and five key research directions are put forward: (1) influences of multi-factor linkage and multi-scale superposed effect on drought formation; (2) studies on climate models that systematically integrate human activities and decisions with their associated feedbacks; (3) effects of land-atmosphere coupling and atmospheric circulation on drought; (4) knowledge of the key process of drought disaster impact on food security and ecological security; (5) research on improving the accuracy of drought prediction under different climate scenarios in the future.

Arid and semi-arid regions constitute approximately one-third of the total land area in China and are vulnerable to the effects of global climate change. Over the past century, a large number of studies have investigated regional climate change and its impacts. However, the conclusions are inconsistent due to differing research perspectives, and this has highlighted the urgent need to obtain systematic, scientific knowledge through review and synthesis. This study, based on a survey of all available literature, reviews the evolution of regional climate change and its effects in the arid and semi-arid regions of China over the last century. The present review examines three aspects of the surveyed previous studies: data, methods, and subjects, and then summarizes essential scientific findings into four subject areas: the origin and expansion of arid and semi-arid regions, the characteristics of climate change in these areas, the drivers of climate change in arid and semi-arid zones, and the consequences of climate change in such environments. Finally, six key directions for future research on climate change and its effects on the arid and semi-arid regions of China are proposed.

Under the background of global warming, significant changes have occurred in the regional climate and extreme events in China. A deep understanding of the changing patterns and driving mechanisms of regional climate and extreme events is of great scientific significance for climate change adaptation and disaster risk management. This study reviewed and summarized the latest scientific advancements, and compared the consistency and differences in climate change responses between eastern and western China. It is indicated that since 1961, temperature and precipitation in China have shown an overall increasing trend, with precipitation changes displaying distinct regional characteristics. A notable feature of climate change in western China is “warming–wetting,” mainly in Northwest China and the northern Qinghai–Xizang Plateau, while some areas in Southwest China exhibit aridification characteristics of “warming–drying.” In eastern China, precipitation has maintained a “southern flood–northern drought” pattern. However, since 2010, this pattern has gradually changed due to a significant increase in precipitation in Northeast and North China. With climate warming, the frequency and intensity of extreme high temperatures, heavy rainfall, and drought events have significantly increased. Human activity, primarily related to greenhouse gas emissions, is the main driving factor behind observed increases in average temperatures and extreme temperatures. Noticeably, inter-nal variability of the climate system has also contributed to changes in regional precipitation. Finally, this study outlines key scientific issues and challenges for future research of climate change in China.