A multi-scalar drought index sensitive to global warming: the standardized precipitation evapotranspiration index – SPEI
We propose a new climatic drought index: the Standardized Precipitation Evapotranspiration Index (SPEI). The SPEI is based on precipitation and temperature data, and has the advantage of combining a multi-scalar character with the capacity to include the effects of temperature variability on drought...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2010 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/22405 |
| Acceso en línea: | http://hdl.handle.net/10261/22405 |
| Access Level: | acceso abierto |
| Palabra clave: | Drought Drought index Log-logistic distribution Global warming Standardized Precipitation Index Palmer Drought Severity Index Precipitation Evapotranspiration |
| Sumario: | We propose a new climatic drought index: the Standardized Precipitation Evapotranspiration Index (SPEI). The SPEI is based on precipitation and temperature data, and has the advantage of combining a multi-scalar character with the capacity to include the effects of temperature variability on drought assessment. The procedure to calculate the index is detailed, and involves a climatic water balance, the accumulation of deficit/surplus at different time scales, and adjustment to a Log-logistic probability distribution. Mathematically, the SPEI is similar to the Standardized Precipitation Index (SPI), but includes the role of temperature. As the SPEI is based on a water balance, it can be compared to the self-calibrated Palmer Drought Severity Index (sc-PDSI). We compared time series of the three indices for a set of observatories with different climate characteristics, located in different parts of the world. Under global warming conditions only the sc-PDSI and SPEI identified an increase in drought severity associated with higher water demand due to evapotranspiration. Relative to the sc-PDSI, the SPEI has the advantage of being multi-scalar, which is crucial for drought analysis and monitoring. |
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