Arid Zone Research ›› 2022, Vol. 39 ›› Issue (2): 359-367.doi: 10.13866/j.azr.2022.02.03

• Weather and Climate • Previous Articles     Next Articles

Analysis of tempo-spatial characteristics and trends of precipitation in the Aral Sea Basin

WANG Haoxuan1(),HUANG Feng1,2(),GUO Lidan2,3,ZHONG Ruisen4   

  1. 1. College of Hydrology and Water Resources, Hohai University, Nanjing 210098, Jiangsu, China
    2. International River Research Centre, Hohai University, Nanjing 211100, Jiangsu, China
    3. Business School of Hohai University, Nanjing 211100, Jiangsu, China
    4. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
  • Received:2021-07-16 Revised:2021-09-07 Online:2022-03-15 Published:2022-03-30
  • Contact: Feng HUANG E-mail:465412917@qq.com;huangfeng1987@hhu.edu.cn

Abstract:

In this study, we extracted regional precipitation data of the general Aral Sea Basin in Central Asia from the Climate Research Unit (CRU) from 1945 to 2019. Simultaneously, we also calculated the spatial and temporal characteristics of annual precipitation change using the climate trend rate method. We first depicted the overall spatial distribution of the climate trend rate, then we used concentration period, concentration degree, and sharing entropy methods to describe the precipitation distribution, and separately depicted the spatial and temporal precipitation distribution. Additionally, we calculated the spatial and temporal change in precipitation complexity using the sample entropy and permutation entropy methods, and demonstrated these results graphically. Trends in the new series of concentration period, concentration degree, sharing entropy, sample entropy, and permutation entropy were tested using the Mann-Kendall method. Generally, the annual precipitation in the Aral Sea Basin in Central Asia remained largely unchanged, whereas precipitation showed a slight upward trend. From the perspective of spatial distribution, precipitation increased significantly in the northwest and central east of the Aral Sea Basin in Central Asia. Furthermore, precipitation was mainly concentrated in early and mid-February for each year. The general precipitation distribution showed a slightly homogenized trend, whereas the annual precipitation distribution was more uniform in the west, north, and east of the Aral Sea Basin, and more concentrated in the middle and south of the Aral Sea Basin. Moreover, the sample entropy and permutation entropy values were higher in the north, west, and east, but lower in the south and middle of the Aral Sea Basin. Altogether, the results demonstrate that the complexity of the precipitation series was relatively high in the north, west, and east, but relatively low in the south and middle of the Aral Sea Basin in Central Asia. The complexity of the precipitation series in the whole basin generally showed an upward trend. More specifically, the complexity of the precipitation series in the north and south of the basin showed a significant downward trend, whereas in the west, middle, and east of the basin, it showed a significant upward trend. Our results illustrate the variation in precipitation characteristics in this basin over the past 75 years, and provide a scientific basis for the development and utilization of water resources in the Aral Sea Basin in Central Asia.

Key words: the Aral Sea Basin, precipitation, inter-annual variability, intra-annual distribution, complexity