Arid Zone Research ›› 2024, Vol. 41 ›› Issue (7): 1099-1111.doi: 10.13866/j.azr.2024.07.02

• Weather and Climate • Previous Articles     Next Articles

Drought trends in Ordos from 1961 to 2020 based on meteorological precipitation anomaly percentage

LI Ye1(), JIANG Wei1(), CHEN Xiaojun2, WU Yingjie2, WANG Sinan2   

  1. 1. College of Water Resources and Architectural Engineering, Northwest A & F University, Yangling 712100, Shaanxi, China
    2. Institute of Water Resources for Pastoral Area Ministry of Water Resources, Hohhot 010020, Inner Mongolia, China
  • Received:2023-10-20 Revised:2024-04-24 Online:2024-07-15 Published:2024-08-01

Abstract:

Due to the frequent occurrence of drought events in Ordos, the local economic development has been seriously affected. Therefore, it is necessary to study the temporal and spatial evolution characteristics of droughts. This study used the monthly precipitation data of 85 grid points in Ordos from 1961 to 2020. It analyzed the applicability of the Standardized Precipitation Index and Precipitation Anomaly Percentage in the region by using the run theory. It further examined the temporal and spatial evolution characteristics of drought by inverse distance interpolation. The conclusions were (1) The Pa index had strong sensitivity and accuracy for drought description. (2) The interannual variation of drought was characterized by high frequency, low intensity, and robust continuity. In terms of seasonal changes, the frequency of summer drought was the highest, reaching 16.7%, and that of winter drought was the lowest, at only 13.3%; the drought incidence gradually decreased with an increase in the drought level. (3) The western part of the study area was more prone to enhanced drought levels than the eastern part. Simultaneously, the probability of being unaffected by drought has gently elevated from 42% to 75%. (4) The drought situation in the spring and summer impacted the annual drought situation the most; the situation in autumn and winter improved, more obviously in winter.

Key words: gridded dataset, drought characteristic, run theory, standardized precipitation index, precipitation anomaly percentage