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Arid Land Geography ›› 2021, Vol. 44 ›› Issue (4): 953-961.doi: 10.12118/j.issn.1000–6060.2021.04.08

• Climatology and Hydrology • Previous Articles     Next Articles

Regression analysis of the rainfall enhancement effect by rocket seeding at summer and autumn in Karamay

LI Bin1(),ZHENG Bohua1(),LAN Wenjie2,YANG Lin2,DOU Chunling2   

  1. 1. Weather Modification Office of Xinjiang Uygur Autonomous Region, Urumqi 830002, Xinjiang, China
    2. Karamay Meteorological Bureau in Xinjiang, Karamay 834000, Xinjiang, China
  • Received:2020-04-07 Revised:2021-05-05 Online:2021-07-25 Published:2021-08-02
  • Contact: Bohua ZHENG E-mail:btlibin@126.com;115125991@qq.com

Abstract:

Via an analysis of the effect of rainfall enhancement by rocket seeding during summer and autumn in Karamay City, Xinjiang, China in recent years, this paper provides distribution characteristics of the distance between the operation effect and the operation point and a relationship between the operation effect and the rocket projectile quantity, so as to provide a scientific basis for better artificial rainfall operation on the ground in the future. Using precipitation data from the Karamay and Baikouquan Weather Stations from June to September in the period of 1990—2017 and from the Shihuachang Weather Station from June to September in the period of 1994—2017, the effect of rainfall enhancement by rocket seeding during summer and autumn in Karamay in the period of 2015—2017 was analyzed using a regression analysis method with the Baikouquan Weather Station as the comparison site and the Karamay and Shihuachang Weather Stations as the target sites. The effect at the Shihuachang Weather Station, approximately 9 km from the operation site, was better than that at the Karamay Weather Station, approximately 4 km from the operation site. This indicates that the rainfall enhancement effect is smaller at areas too close or too far from the operation point. More operation times in one month improves the rainfall enhancement effect, with 5-7 rocket projectiles per operation improving the rainfall enhancement effect. Therefore, good effects of rainfall enhancement by rocket seeding are likely located a certain distance downwind of the operation point and the number of rocket projectiles per operation needs to be appropriate: too many projectiles may cause rain reduction, while too few may degrade the catalytic effect. The operation of rainfall enhancement on the ground, especially the operation of rainfall enhancement for convective clouds on the ground, needs to be combined with weather radar echo data to determine the operation object index to implement rainfall enhancement more scientifically and reasonably. Even though this paper analyzes the effect of rainfall enhancement by rocket seeding during summer and autumn, there is a limited number of samples and these effects need to be further analyzed and studied in the future. In particular, it is necessary to include weather radar echo data to conduct further research and analyses to obtain the macro and micro physical changes of clouds and precipitation before and after the operation of rainfall enhancement on the ground and to conduct physical or statistical assessments of the operation effect to further enhance the credibility of assessments of this effect.

Key words: rainfall enhancement, regional regression, effect analysis, Karamay