Recent signal and impact of wet-to-dry climatic shift in Xinjiang, China

Abstract

The Xinjiang region of China is among the most sensitive regions to global warming. Based on the meteorological and hydrological observation data, the regional wet-to-dry climate regime shifts in Xinjiang were analyzed and the impacts of climatic shift on the eco-hydrological environment of Xinjiang were assessed in this study. The results showed that temperature and precipitation in Xinjiang have increased since the mid-1980s, showing a warming-wetting trend. However, drought frequency and severity significantly increased after 1997. The climate of Xinjiang experienced an obvious shift from a warm-wet to a warm-dry regime in 1997. Since the beginning of the 21st century, extreme temperatures and the number of high temperature days have significantly increased, the start date of high temperature has advanced, and the end date of high temperature has delayed in Xinjiang. In addition, the intensity and frequency of extreme precipitation have significantly increased. Consequently, regional ecology and water resources have been impacted by climatic shift and extreme climate in Xinjiang. In response, satellite-based normalized difference vegetation index showed that, since the 1980s, most regions of Xinjiang experienced a greening trend and vegetation browning after 1997. The soil moisture in Xinjiang has significantly decreased since the late 1990s, resulting in adverse ecological effects. Moreover, the response of river runoff to climatic shift is complex and controlled by the proportion of snowmelt to the runoff. Runoff originating from the Tianshan Mountains showed a positive response to the regional wet-to-dry shift, whereas that originating from the Kunlun Mountains showed no obvious response. Both climatic shift and increased climate extremes in Xinjiang have led to intensification of drought and aggravation of instability of water circulation systems and ecosystem. This study provides a scientific basis to meet the challenges of water resource utilization and ecological risk management in the Xinjiang region of China.

Comparison of summer raindrop size distribution characteristics in the western and central Tianshan Mountains of China

“…Previous studies have indicated that there are obvious differences in the characteristics of RSD for different rainfall rate classes (Bringi et al, 2003; Chen et al, 2017; Janapati et al, 2020; Ma et al, 2019; Tokay & Short, 1996). Xinjiang is located in the northwest of China, far away from the ocean, resulting in a continental arid climate (Huang et al, 2015; Yao et al, 2021). Considering the fact of high frequency of low rainfall rates in Xinjiang, the RSD data collected at Zhaosu and Tianchi are subdivided into five rainfall rate classes: R1: 0.1–0.5 mm h −1 , R2: 0.5–1 mm h −1 , R3: 1–3 mm h −1 , R4: 3–5 mm h −1 , R5: ≥5 mm h −1 .…”

“…Xinjiang is located in the northwest of China, far away from the ocean, resulting in a continental arid climate (Huang et al, 2015; Yao et al, 2021). The Tianshan Mountains in Xinjiang are known as the ‘Water Tower of Central Asia’.…”

“…Xinjiang is located in the northwest of China, far away from the ocean, resulting in a continental arid climate at Zhaosu and Tianchi are also given in Figure 3. (Huang et al, 2015;Yao et al, 2021). Considering the fact of high frequency of low rainfall rates in Xinjiang, the RSD data collected at Zhaosu and Tianchi are subdivided into five rainfall rate classes: R1: 0.1-0.5 mm h À1 , R2: 0.5-1 mm h À1 , R3: 1-3 mm h À1 , R4: 3-5 mm h À1 , R5: ≥5 mm h À1 .…”

“…Xinjiang is located in the northwest of China, far away from the ocean, resulting in a continental arid climate (Huang et al, 2015; Yao et al, 2021). Because of the complex terrain in Xinjiang, the distribution of precipitation is extremely uneven, and the precipitation in mountainous areas is obviously larger than that in plain areas.…”

Changes in the spatial and temporal characteristics of China’s arid region in the background of ENSO

“…Besides, changes in the distribution of precipitation and drought in Northwest China have been noted in some studies 13 , 29 , 37 . In our study, the spatial center of precipitation in the arid region is used to analyze the changes, and the results show that the longitude of the spatial center of precipitation in the arid region presents a complex and continuous periodic change, while the latitude of the spatial center of precipitation in the arid region is relatively stable before 2000 and then began to fluctuate greatly.…”