Investigating the Spatiotemporal Dynamics of Temperature and Precipitation Extremes Across the Loess Plateau Region in China During 1982-2023

Rashid, Abdur , Xinyu, Zhang , Qixiang, Wang

2026-01-01 INTERNATIONAL JOURNAL OF CLIMATOLOGY 2026   46(卷), 1(期), (null页)

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The Loess Plateau Region (LPR) in China, identified as one of the world's most severely affected areas by soil erosion, contains fragile ecosystems highly susceptible to climate variability. This study examines the long-term trends and abrupt shifts in temperature and precipitation extremes across the LPR from 1982 to 2023, offering a comprehensive assessment of climate change in this sensitive region. Homogenised daily data for the mean (T-mean), maximum (T-max) and minimum (T-min) temperatures, along with precipitation (PPT), were collected from 160 meteorological stations. Data quality control and homogenisation were performed using RHtestsV3. The datasets were interpolated onto a 0.75 degrees x 0.75 degrees grid via ordinary Kriging in ArcGIS. Monotonic trends were analysed using the Mann-Kendall test and Sen's slope, with iterative pre-whitening to mitigate autocorrelation bias. Abrupt shifts were detected using the Mann-Whitney U test, with significance assessed via Z-values and Monte Carlo simulations. We found a significant regional warming of annual T-mean at 0.0177 degrees C/year (approximate to 0.71 degrees C since 1982). Annual T-max changed little (0.002 degrees C/year, non-significant), whereas T-min decreased overall (-0.051 degrees C/year), despite spring-summer T-min increases and winter T-min cooling (-0.018 degrees C/year). Consequently, the diurnal temperature range widened, especially in winter. The strongest warming occurred in winter and spring, with over 83% of grid cells exhibiting significant trends (p < 0.05). Precipitation increased significantly (4.81 mm/year; 200 mm over the study period), predominantly during the rainy season (+3.02 mm/year). Spatial variability was notable, where 41% of grid cells showed precipitation increases, while 13% exhibited declines, particularly in the southeastern LPR. Abrupt shifts affected 27% of temperature and 18.5% of precipitation grid cells, predominantly around 1993-1997 and 2009-2012; however, these shifts were localised and not statistically significant at the regional scale. Persistent warming and moderately increasing precipitation characterise the LPR's recent climate, underscoring the necessity for continued monitoring and adaptive strategies to address the impacts of temperature and precipitation extremes in this vulnerable region.