Page 67 - 《高原气象》2025年第3期

3 期 刘玉鹏等：1959—2018年黄土高原地区降水时空变化研究 625

Study on the Spatio-Temporal Changes of Precipitation in

Loess Plateau from 1959 to 2018

1， 2
1， 2
LIU Yupeng ， CHAO Jinlong ， LU Yamin ， WANG Yaxin ， BI Yuting 3
1
1
（1. School of Geographic Sciences， Taiyuan Normal University， Jinzhong 030619， Shanxi， China；
2. Shanxi Key Laboratory of Earth Surface Processes and Resource Ecology Security in
Fenhe River Valley， Jinzhong 030619， Shanxi， China；
3. Shanxi Meteorological Observatory， Taiyuan 030006， Shanxi， China）

Abstract： Precipitation plays a critical role in the Earth's hydrological and energy cycles， significantly influenc‐
ing the biogeochemical cycles and energy exchanges on the land surface. In the ecologically fragile region of the
Loess Plateau， the spatial and temporal variability of precipitation has profound implications for both the ecologi‐
cal environment and socioeconomic development. Therefore， study on the spatial and temporal variations of pre‐
cipitation in the Loess Plateau holds substantial theoretical and practical significance. This study utilizes daily pre‐
cipitation data from 115 meteorological stations across the Loess Plateau and its surrounding areas， covering the
period from 1959 to 2018. By employing methods such as Inverse Distance Weighting （IDW） interpolation and
wavelet analysis， the study provides a comprehensive analysis of the spatial and temporal characteristics of pre‐
cipitation over the past 60 years in the Loess Plateau. The results showed that： （1） The spatial distribution of pre‐
cipitation in the Loess Plateau exhibits a clear "stepped" pattern， gradually decreasing from southeast to north‐
west. This distribution highlights a significant gradient where the southeastern regions receive more precipitation
than the northwestern regions， with a similar trend of more rainfall in the south compared to the north. Further‐
more， localized topography plays a crucial role in modulating precipitation， with higher elevations generally re‐
ceiving more rainfall.（2） Under the influence of changes in the East Asian monsoon and atmospheric circulation
patterns， the spatial distribution of precipitation from 1989 to 2018 differs significantly from that of 1959 to
1988. Specifically， the 200mm and 400mm isohyets have shifted northward， with a notable decrease in precipita‐
tion in the southeastern monsoon-dominated areas， while precipitation has increased in the non-monsoon north‐
western areas. The monsoon marginal zone of the Loess Plateau is particularly sensitive to monsoon variability.
The continuous weakening of the East Asian summer monsoon has diminished the capacity for moisture trans‐
port， further exacerbated by El Niño-Southern Oscillation （ENSO） warm events， both of which have contribut‐
ed to reduced precipitation in the southeast. Conversely， changes in atmospheric circulation have led to increased
precipitation in the northwest， resulting in a slight expansion of the semi-humid regions in the area.（3） Over the
study period， precipitation in the Loess Plateau exhibits a fluctuating upward trend， indicative of a general ten‐
dency towards increased wetness in the region. This suggests a long-term shift towards more humid conditions，
which could have significant implications for the region's ecological restoration and water resource management.
（4） The interannual variability of precipitation in the Loess Plateau is characterized by oscillations on multiple
time scales， specifically at 5-year， 7-year， 11-year， and 43~45-year intervals， with the 5-year cycle identified as
the dominant periodicity.
Key words： Loess Plateau； precipitation； spatio-temporal variation； inverse distance weighted interpolation；
wavelet analysis