Detecting persistence of meteorological drought via the Hurst exponent
METEOROLOGICAL APPLICATIONS, cilt.22, sa.4, ss.763-769, 2015 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 22 Sayı: 4
- Basım Tarihi: 2015
- Doi Numarası: 10.1002/met.1519
- Dergi Adı: METEOROLOGICAL APPLICATIONS
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Sayfa Sayıları: ss.763-769
- Anahtar Kelimeler: Hurst exponent, Mann-Kendall, PDSI, Persistence, Trend, Turkey, LONG-TERM-MEMORY, VARIABILITY, PRECIPITATION, TEMPERATURES, CIRCULATION, SEVERITY, MAXIMUM, TURKEY, TRENDS
- Çanakkale Onsekiz Mart Üniversitesi Adresli: Evet
Özet
This study proposes the Hurst exponent (H) to detect persistence in the Palmer Drought Severity Index (PDSI) over Turkey. Since a fractal structure admits the behaviour of global determinism and local randomness, the H exponent values could be used to detect self-similar statistical structure of the time series. Additionally, the H value >0.5 and near 1 shows the intensity level of persistence. The term persistence may be assessed as a criterion to be used as a measure of predictability. Moreover, the predictability index, fractal dimension and autocorrelation function of the PDSI values can also be obtained from the H values. Nevertheless, it is not easy to find a spatial meaning of information content of the results obtained by the methods used in the present study. For that reason, the Mann-Kendall (MK) trend test was also used, and the results showed that significant negative trends are widespread throughout the country. As expected, the H values were close to 1 in places where statistically significant trends exist. The high values of the H exponent in all the regions can be explained by the droughts observed there that might be caused due to the possible associations with the large-scale atmospheric circulations. In this context, it is suggested that the droughts can be predictable by constructing the appropriate general climate circulation models.