Instituto Interamericano de Tecnología y Ciencias del Agua IITCA-UAEM et al. (2025) Sensibilidad de índices de sequía dependiendo de la longitud de registros climatológicos

Identification

• Journal: Tecnología y Ciencias del Agua
• Year: 2025
• Date: 2025-10-31
• Authors: Aleida Yadira Vilchis-Francés, Carlos Díaz-Delgado
• DOI: 10.24850/j-tyca-2025-06-09

Research Groups

• Instituto Interamericano de Tecnología y Ciencias del Agua (IITCA-UAEM), Toluca, México

Short Summary

This study evaluates the sensitivity of various meteorological drought indices to the length of climatological records, aiming to determine which indices exhibit less uncertainty when applied with short time series. It identifies several indices (CPI, PNI, RDI, SPI, SPEI, ZI) as less sensitive to record length, with SPEI requiring at least 10 years and others 20 years, while EDI needs over 30 years for improved certainty.

Objective

• To evaluate the sensitivity of meteorological drought indices to the length of available climatological records and determine the associated estimation error, particularly when using short time series.

Study Configuration

• Spatial Scale: Methodological evaluation applicable to various regions with different geomorphologies and climatic regimes, with a note on higher reliability in areas with greater annual precipitation.
• Temporal Scale: Evaluation against synthetic series of 1000 years; sensitivity thresholds identified for record lengths of 10, 20, and 30 years.

Methodology and Data

• Models used: Meteorological drought indices including CPI (Climatic Precipitation Index), PNI (Precipitation Normalcy Index), RDI (Reconnaissance Drought Index), SPI (Standardized Precipitation Index), SPEI (Standardized Precipitation Evapotransranspiration Index), ZI (Z-Score Index), and EDI (Effective Drought Index).
• Data sources: Synthetic daily time series of precipitation (P), maximum temperature (Tmax), and minimum temperature (Tmin) generated based on characteristics of real meteorological samples, using normal and gamma probability distribution functions.

Main Results

• The indices CPI, PNI, RDI, SPI, SPEI, and ZI showed low sensitivity to the length of meteorological records.
• SPEI became insensitive to record length with data series of 10 years or more.
• CPI, PNI, RDI, SPI, and ZI became insensitive to record length with data series of 20 years or more.
• EDI was more sensitive to record length, requiring more than 30 years of data to improve its certainty.
• The reliability of the indices was higher for synthetic daily series of P, Tmax, and Tmin generated with the normal distribution function, and in zones with higher annual precipitation.

Contributions

• Provides a systematic process for evaluating the sensitivity of meteorological drought indices to the length of climatological records.
• Quantifies the minimum record lengths required for several widely used drought indices to achieve acceptable certainty, addressing a common issue of short meteorological time series.
• Offers guidance on index selection based on data availability and regional characteristics, particularly regarding the choice of distribution function for synthetic data generation and the impact of annual precipitation levels.

Funding

• Not explicitly mentioned in the provided text.

Citation

@article{InstitutoInteramericanodeTecnologíayCienciasdelAguaIITCAUAEM2025Sensibilidad,
  author = {Instituto Interamericano de Tecnología y Ciencias del Agua IITCA-UAEM, Toluca, México and Vilchis-Francés, Aleida Yadira and Díaz-Delgado, Carlos and Instituto Interamericano de Tecnología y Ciencias del Agua IITCA-UAEM, Toluca, México},
  title = {Sensibilidad de índices de sequía dependiendo de la longitud de registros climatológicos},
  journal = {Tecnología y Ciencias del Agua},
  year = {2025},
  doi = {10.24850/j-tyca-2025-06-09},
  url = {https://doi.org/10.24850/j-tyca-2025-06-09}
}