Spatiotemporal Analysis of Meteorological Drought Variability in the Indian Region Using Standardized Precipitation Index

TL;DR

This study analyzes the spatiotemporal patterns of drought in India from 1951 to 2007 using the Standardized Precipitation Index, revealing trends and key drought years to improve understanding of drought variability.

Contribution

It introduces a comprehensive analysis of drought patterns in India using SPI at a 1-degree grid resolution over multiple decades, highlighting trends and severe drought years.

Findings

2002 had widespread dryness in July.

Increasing trend in drought area under dryness in July.

1987 was the most severe drought year.

Abstract

Grid (1{\deg} latitude x 1{\deg} longitude) level daily rainfall data over India from June to September for the years 1951 to 2007, generated by India Meteorological Department, was analyzed to build monthly time series of Standardized Precipitation Index (SPI). Analysis of SPI was done to study the spatial and temporal patterns of drought occurrence in the country. Geographic spread of SPI derived Area under Dryness (AUD) in different years revealed the uniqueness of 2002 drought with wide spread dryness in July. Mann-Kendal trend analysis and moving average based trends performed on AUD indicated increasing trend in July. The area under moderate drought frequency has increased in the most recent decade. Ranking of years based on Drought Persistency Score (DPS) indicated that the year 1987 was the severe-most drought year in the country. The results of the study have revealed various aspects of drought climatology in India. A similar analysis with the SPI of finer spatial resolution and relating it to crop production would be useful in quantifying the impact of drought in economic terms.