Statistical Analysis of the Total Number of Dry Months in Eastern Georgia in 1936-2023 Using the SPI-3 Index ≤ 0 and an Assessment of the Variability of this Number until 2045
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Abstract
A detailed statistical analysis of the total number of dry months (N) in Eastern Georgia in 1936-2023 using the SPI-3 index ≤ 0 (agricultural drought) and an assessment of the variability of this number until 2045 is presented. Data from 18 meteorological stations on monthly precipitation sums were used. In particular, the following results were obtained.
The features of intra-annual distribution of monthly N values in Eastern Georgia in 1936-2023 (Full period), 1936-1975 (I period) and 1984-2023 (II period) were studied. Overall, in the second period compared to the first for all stations, a trend of increasing aridity was observed in 136 cases (months), decreasing in 65 cases, and remaining constant in only 15 cases. In other words, the overall trend is toward increasing aridity.
Statistical analysis of N values in spring-autumn period was conducted. In the second period of time compared to the first, mean N values in spring-autumn period for Paravani, Tsalka, Bolnisi, Sagarejo, Gurjaani, Kvareli, Tianeti, Pasanauri and Stepantsminda are significant increase (aridity tendency). Only at one station (Lagodekhi) is observed significant decrease of this difference (wetting tendency). Insignificant variability of the values of N in second period compared to first are observed at the 8 stations: Gardabani, Tbilisi, Dedoplistskaro, Telavi, Gudauri, Gori, Khashuri and Shovi.
Statistical forecasting of N values in spring-autumn period up to 2045 was carried out. At all stations, except Tbilisi, Lagodekhi and Shovi in 2026-2045 compared to 2004-2023 on average, an increase in drought is expected.
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References
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