The Application of Box–Cox Transformation to Determine the Standardised Precipitation Index (SPI), the Standardised Discharge Index (SDI) and to Identify Drought Events: Case Study in Eastern Kujawy (Central Poland)
| Autor: | R. Glazik, Sebastian Tyszkowski, Arkadiusz Bartczak |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Environmental Engineering
Index (economics) rozkład normalny Kujawy Wschodnie Geography Planning and Development Gaussian distribution SPI homogenicznosc szeregów lcsh:River lake and water-supply engineering (General) Development SDI Normal distribution variance homogeneity Precipitation przekształcenie Boxa-Coxa Water Science and Technology okresy suche Hydrology Series (stratigraphy) lcsh:TC401-506 Discharge Homogeneity (statistics) trend kroczqcy Power transform Box–Cox transformation Agricultural and Biological Sciences (miscellaneous) Eastern Kujawy Skewness moving trend Environmental science Physical geography meteorological drought |
| Zdroj: | Journal of Water and Land Development, Vol 22, Iss 1, Pp 3-15 (2014) |
| ISSN: | 2083-4535 |
| Popis: | The article presents the results of research into the transformation of series of hydro-meteorological data for determining dry periods with the Standardised Precipitation Index (SPI) and the Standardised Discharge Index (SDI). Time series from eight precipitation stations and five series of river discharge data in Eastern Kujawy (central Poland) were analysed for 1951–2010. The frequency distribution of the series for their convergence with the normal distribution was tested with the Shapiro–Wilk test and homogeneity with the Bartlett's test. The transformation of the series was done with the Box–Cox technique, which made it possible to homogenise the series in terms of variance. In Poland, the technique has never been used to determine the SPI. After the transformation the distributions of virtually all series complied with the normal distribution and were homogeneous. Moreover, a statistically significant correlation between the δ transformation parameter and the skewness of the series of monthly precipitation was observed. It was similar for the series of mean monthly discharges in the winter half-year and the hydrological year. The analysis indicates an alternate occurrence of dry and wet periods both in case of precipitation and run-offs. Drought periods coincided with low flow periods. Thus, the fluctuations tend to affect the development of agriculture more than long-term ones. |
| Databáze: | OpenAIRE |
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