Extreme rainfall deficits were not the cause of recurring colonial era famines of southern Indian semi-arid regions

Ranjini Ray,Kushank Bajaj,Gaurav Arora,Shi Chen,Keyle Horton,Atreyee Bhattacharya,Amir Bazaz,Supriyo Chakraborty

doi:10.1038/s41598-021-96826-2

Abstract

Using information contained in the eighteenth to twentieth century British administrative documents, preserved in the National Archives of India (NAI), we present a 218-year (1729–1947 AD) record of socioeconomic disruptions and human impacts (famines) associated with ‘rain failures’ that affected the semi-arid regions (SARs) of southern India. By mapping the southern Indian famine record onto long-term spatiotemporal measures of regional rainfall variability, we demonstrate that the SARs of southern India repeatedly experienced famines when annual rainfall reduced by ~ one standard deviation (1 SD), or more, from long-term averages. In other words, ‘rain failures’ listed in the colonial documents as causes of extreme socioeconomic disruptions, food shortages and human distress (famines) in the southern Indian SARs were fluctuations in precipitation well within the normal range of regional rainfall variability and not extreme rainfall deficits (≥ 3 SD). Our study demonstrates that extreme climate events were not necessary conditions for extreme socioeconomic disruptions and human impacts rendered by the colonial era famines in peninsular India. Based on our findings, we suggest that climate change risk assessement should consider the potential impacts of more frequent low-level anomalies (e.g. 1 SD) in drought prone semi-arid regions.

Highlights

The area of peninsular India bounded between the Balaghat ranges in the north, the Western Ghats along the west, and the eastern coast along the east and south is categorized as the semi-arid region or SARs of southern India[6,7,22]
We have reviewed over 600 colonial administrative documents preserved in the Public Records, Microfilms and Private papers sections of the National Archives of India (NAI), New Delhi
These NAI documents consist of official letters, meeting minutes and correspondences that were used for exchanging information related to financial and administrative management between district level tax collectors and senior management headquartered in Bombay, Madras and London (Fig. 1 and SI Section B-C)

Summary

Introduction

The area of peninsular India bounded between the Balaghat ranges in the north, the Western Ghats (or Shyadris) along the west, and the eastern coast along the east and south is categorized as the semi-arid region or SARs of southern India[6,7,22] While the western interior region receives rainfall mainly from the southwest monsoon, the southern interior receives rainfall from both arms of the ISM6,7,22 The geographical and climatological setting creates a gradient in rainfall from the coast to the interior, with the interiors of both southern and western India receiving between 100 and 600 mm of rainfall annually compared to > 2000 mm of rainfall that the western coastal region receives and ~ 1200 mm of rainfall that the south eastern coast receives[22]

Methods

Results

Conclusion