Spatial and temporal variation of precipitation characteristics in the semiarid region of Xi'an, northwest China

Hao Han,Wenchao Qi,Rengui Jiang,Yongde Kang,Ganggang Bai,Jingming Hou,Yuan Li,Bingyao Li,Jiahui Gong

doi:10.2166/wcc.2021.048

Abstract

AbstractPrecipitation variations mostly affect the water resource planning in semi-arid regions of northwest China. The objective of this study is to quantitatively explore the spatial and temporal variations of precipitation in different time scales in Xi'an city area. The Mann–Kendall test and wavelet analysis methods were applied to analyze the precipitation variability. In terms of temporal variation of precipitation, the results indicated that the annual precipitation exhibited a significant decreasing trend during 1951–2018. Except for summer precipitation representing a slightly increasing trend, the other seasonal precipitations had a similar decreasing trend to annual precipitation throughout 1951–2018. The monthly precipitation had different change trends, showing the precipitation from June to September could account for 58.4% of the total annual precipitation. In addition, it was clear that annual precipitation had a significant periodic change, with the periods of 6, 13, 19, and 27 years. For the spatial variation of precipitation during 1961–2018, the results showed that annual and seasonal precipitation exhibited obvious spatial differences, indicating an increasing spatial trend from north to south. Thus, understanding the precipitation variation in Xi'an city can provide a theoretical foundation of future water resources management for other cities in semi-arid regions of northwest China.

Highlights

Precipitation is the essential element to explore hydrological processes (Emmanuel et al ), showing significant variability in terms of frequency, duration, intensity, and trend (Sang et al )
It is obvious that the annual precipitation exhibited a decreasing trend of À1.0133 mm yr-1 according to the linear regression coefficient value
Based on the long-term measured precipitation data (1951– 2018), this study investigated the spatial and temporal variations of precipitation in Xi’an city

Summary

Introduction

Precipitation is the essential element to explore hydrological processes (Emmanuel et al ), showing significant variability in terms of frequency, duration, intensity, and trend (Sang et al ). The spatial and temporal variability of precipitation can significantly affect runoff generation in urban catchments (Segond et al ; Emmanuel et al ; Zhang et al ). It is important to identify its driving potential of extreme events to affect socioeconomic conditions to evaluate the spatial and temporal variation of precipitation (Sharma et al ). The periodicity, spatial and temporal characteristics of precipitation change have received wide attention from government regulators and many scholars (Li et al ; Xing et al ; Thomas & Prasannakumar ; Yang et al ; Ding et al ). China’s sponge city development policy was put forward to solve many urban waterlogging issues which are due to frequent extreme precipitation events (Ding et al ; Ma et al ). It is important to systematically evaluate the spatial and temporal variations of precipitation to help us upgrade the understanding of precipitation variability

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Conclusion