Conditional Copula-Based Spatial–Temporal Drought Characteristics Analysis—A Case Study over Turkey
| Autor: | Mahdi Hesami Afshar, Mustafa Yilmaz, Ali Unal Sorman |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
Multivariate statistics
lcsh:Hydraulic engineering 010504 meteorology & atmospheric sciences 0208 environmental biotechnology Geography Planning and Development temporal SPI 02 engineering and technology Bivariate analysis drought Aquatic Science 01 natural sciences Biochemistry Copula (probability theory) multivariate lcsh:Water supply for domestic and industrial purposes Joint probability distribution lcsh:TC1-978 Statistics parasitic diseases Econometrics copula spatial 0105 earth and related environmental sciences Water Science and Technology Mathematics lcsh:TD201-500 Cumulative distribution function fungi Univariate food and beverages 020801 environmental engineering Precipitation index |
| Zdroj: | Water, Vol 8, Iss 10, p 426 (2016) Afshar, M, Sorman, A U & Yilmaz, M T 2016, ' Conditional copula-based spatial–temporal drought characteristics analysis—a case study over Turkey ', Water, vol. 8, no. 10, 426 . https://doi.org/10.3390/w8100426 Water; Volume 8; Issue 10; Pages: 426 |
| ISSN: | 2073-4441 |
| DOI: | 10.3390/w8100426 |
| Popis: | In this study, commonly used copula functions belonging to Archimedean and Elliptical families are fitted to the univariate cumulative distribution functions (CDF) of the drought characteristics duration ( LD ), average severity ( S ¯ ), and average areal extent ( A ¯ ) of droughts obtained using standardized precipitation index (SPI) between 1960 and 2013 over Ankara, Turkey. Probabilistic modeling of drought characteristics with seven different fitted copula functions and their comparisons with independently estimated empirical joint distributions show normal copula links drought characteristics better than other copula functions. On average, droughts occur with an average LD of 6.9 months, S ¯ of 0.94, and A ¯ of 73%, while such a drought event happens on average once in every 6.65 years. Results also show a very strong and statistically significant relation between S ¯ and A ¯ , and drought return periods are more sensitive to the unconditioned drought characteristic, while return periods decrease by adding additional variables to the analysis (i.e., trivariate drought analysis compared to bivariate). |
| Databáze: | OpenAIRE |
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