Development of a new agro-meteorological drought index (SPAEI-Agro) in a data-scarce region

ABSTRACT

Drought complexity may not be accurately characterized by univariate meteorological or hydrological drought indices under the intensification of hydrological cycle due to climate change and human activities. In particular, such drought indices require long series of hydro-meteorological data, which are unavailable over ungauged and data-scarce catchments. In this study, a multivariate drought index, Standardized Precipitation Actual Evapotranspiration Index-Agro (SPAEI-Agro), is proposed, which combines meteorological and hydrological variables as precipitation (P), actual evapotranspiration (AET), runoff and groundwater (GW) of ungauged catchments and sub-catchment scales with diverse climatology. SPAEI-Agro was able to characterize severe drought events more accurately in humid and dry sub-humid sub-catchments compared to Standardized Precipitation Evapotranspiration Index (SPEI) and Standardized Streamflow Drought Index (SSDI) for Tunga-Bhadra River, India. SPEI (based upon potential evapotranspiration) and SSDI (based on streamflow) showed intensified drought characteristics compared to the new P, AET and GW-based drought indicator SPAEI-Agro in semi-arid and dry sub-humid climates.

KEYWORDS:

• agro-meteorological drought
• climatology
• SPEI
• SSDI
• SWAT
• Tunga-Bhadra

Editor A. Castellarin; Associate Editor B. Bonaccorso

Editor A. Castellarin; Associate Editor B. Bonaccorso

Acknowledgements

The authors sincerely thank Dr P. Somasekhar Rao, Technical Director, at the Advanced Centre for Integrated Water Resources Management (ACIWRM), Bengaluru, Karnataka, India, for providing Tunga-Bhadra basin data.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/02626667.2023.2206969

Additional information

Funding

The research presented in this study was funded by the Ministry of Science & Technology, Department of Science & Technology, TMD (Energy, Water & Others), Water Technology Initiative, Project no. DST/TMD-EWO/WTI/2K19/EWFH/2019/306.