Changes in precipitation amounts and extremes across Xinjiang (northwest China) and their connection to climate indices

Abstract

Xinjiang is a major part of China’s arid region and its water resource is extremely scarcity. The change in precipitation amounts and extremes is of significant importance for the reliable management of regional water resources in this region. Thus, this study explored the spatiotemporal changes in extreme precipitation using the Mann–Kendall (M–K) trend analysis, mutation test, and probability distribution functions, based on the observed daily precipitation data from 89 weather stations in Xinjiang, China during 1961–2018. We also examined the correlations between extreme precipitation and climate indices using the cross-wavelet analysis. The results indicated that the climate in Xinjiang is becoming wetter and the intensity and frequency of extreme precipitation has begun to strengthen, with these trends being more obvious after the 1990s. Extreme precipitation trends displayed spatial heterogeneity in Xinjiang. Extreme precipitation was mainly concentrated in mountainous areas, northern Xinjiang, and western Xinjiang. The significant increasing trend of extreme precipitation was also concentrated in the Tianshan Mountains and in northern Xinjiang. In addition, the climate indices, North Atlantic Oscillation, Atlantic Multidecadal Oscillation, Multivariate ENSO Index and Indian Ocean Dipole Index had obvious relationships with extreme precipitation in Xinjiang. The relationships between the extreme precipitation and climate indices were not clearly positive or negative, with many correlations advanced or delayed in phase. At the same time, extreme precipitation displayed periodic changes, with a frequency of approximately 1–3 or 4–7 years. These periodic changes were more obvious after the 1990s; however, the exact mechanisms involved in this require further study.

Spatiotemporal Pattern of Occurrence Time of Extreme Precipitation and Circulation Mechanisms in the Arid Region of Northwest China

“…No significant abrupt change was detected for EPOT, indicating that regional abrupt variation has not occurred. However, an abrupt change in MEPO in the early 1990s was detected (abrupt point: 1993, passing the significant test at the 95% level), which is in accord with the trends of increasing intensity and frequency of extreme precipitation in Xinjiang after the 1990s (Hu et al, 2021) and the decadal change in summer precipitation in 1991 in ARNC, indicating that it might be affected by the significantly enhanced northward transport of water vapor from low-latitude sea areas (Li and Ma, 2018).…”

“…Precipitation in ARNC is affected by many factors that include the South Asian high (Wei et al, 2017), Asian subtropical westerly jet (Zhao et al, 2013), Indian Ocean Dipole (Hu et al, 2021), El Niño-Southern Oscillation (ENSO) (Lu et al, 2019a), and WPSH (Cheng et al, 2021). The findings regarding EPOT periodicity confirm that oscillations such as those with 2and 7-year periods are associated with the classical bandwidth of ENSO (Branstator et al, 2008), WPSH (Sui et al, 2007;Feng et al, 2016;Li et al, 2016), and EASM (Yang et al, 2011;Ding et al, 2019), and that the 6-years oscillation of MEPO is also related to the classical bandwidth of ENSO, indicating a potential relationship.…”

“…Furthermore, there are regional and seasonal discrepancies in extreme precipitation in ARNC. For instance, in the mountainous regions, the increasing rate of the frequency and the intensity of extreme precipitation have been faster than in other regions (Lin et al, 2017;Hu et al, 2021;Song et al, 2022). The intensity of extreme precipitation significantly weakened in summer while significantly strengthened in winter (Wang et al, 2013;Xiao et al, 2017).…”

Ecotype Division and Chemical Diversity of Cynomorium songaricum from Different Geographical Regions

“…Xinjiang and Qinghai were located in Western China, with abundant rainfall and a warm climate. Besides, salt-alkaline soils were widely distributed in these areas [26]. In contrast, Neimenggu, Qinghai, and Ningxia were located in Central West.…”

Dynamic Variability of Wind Erosion Climatic Erosivity and Their Relationships with Large-Scale Atmospheric Circulation in Xinjiang, China

“…From a statistical perspective, the three climate indices showed relationships to the climatic erosivity in Xinjiang in terms of their correlation and periodicity. This was mainly because Xinjiang is located in the westerly-dominated climatic regime, and climatic conditions were impacted by the latitude wave propagation of the mid-latitude atmospheric circulation [55]. Correlations between the climatic erosivity and the three climate indices were neither simple linear relationships nor simple positive or negative relationships; rather, they were related to an advance or delay in the cycle.…”