Rethinking Climate Change in the Cauvery Delta Through Long Term Historical Data

Lead Research Organisation: University of Manchester
Department Name: School of Medical Sciences


According to the 5th Intergovernmental Panel on Climate Change, 230 million people in South Asia are at risk from
Climate Change, the largest of any single region. Recent studies of the Cauvery delta, and more generally climate
change in India, begin largely with World Bank and Indian Space Research Organization (satellite) data from the
1970s, showing the ways in which the climate is acutely changing since then. However, these studies are based on
thirty years of data. This project uses historical data to comprehend the scale of space specific climate change, the
threats posed, effectively predict long-term trends and prepare adaptation strategies. (Mahony and Endfield 2018;
Amrith 2016). Using long term historical data allows researchers to a) eliminate cyclical patterns not as effects of
immediate climate change b) identify long term patterns of change (whether this is a sudden increase, decrease or
gradual) c) identify how older regimes adapted to change in temperature or disasters.
The project will curate a detailed dataset collected from reports that were published by the colonial provincial
government and continued into the postcolonial era. The first is the Seasonal and Crop report of the Madras presidency
(1905-1954). This report contains district wise monthly statistics and qualitative information on rainfall compared to
the average rainfall for the district, the prevalent temperature, level of silt deposits, the crops grown in different
seasons and any shortfall or excess of rain. Data prior to 1905 is not systematic, but data has been gathered through
three sources including the Meteorological Observations Recorded at Six Stations in India (1879-1894);
Meteorological Observations made at the East India Company's Observatory at Madras (1841-1890); Rainfall of
India (1891-1950) and Cyclone Memoirs (1888-1893). The dataset will comprise of a searchable year-wise monthly
index of rainfall, temperature, silt deposit, crops grown, in a systematic manner from 1905-1950, and in a less
systematic manner from 1860-1905.
I will work with GIS technicians at the French Institute of Pondicherry (IFP) to transfer the data on to maps of two
kinds. First, three historical maps (from 1888, 1917 and 1945, all georeferenced) created will include still images of
these years and contain multiple variables (colour coded), to visualize change clearly. Variables will be added as
colour coded graphics which users can then use to simultaneously picture rainfall, temperature and vegetation
changing over a close to a hundred years. Second, certain maps will picture years of floods or drought (for instance
1872 and 1924), to show how extreme weather events have occurred historically (Knowles and Hillier 2008). The
dataset will allow researchers to ask the following questions
What are the patterns in temperature and rainfall from 1860-1950? Is there evidence of increasing heatwaves and
floods up until 1950? Is there any evidence of cyclical weather patterns? At which time period (under what weather
conditions) was agriculture relatively stable? Which regions have seen the greatest change in crop-type? Is this due to
climate conditions or other factors? (hybrid seeds, use of nitrogen based fertilizer etc.)
Alongside the dataset, I will write the life histories of two farmers to tell a story around climate change, adaptation
and economic precarity over the life-course of farmers in the Cauvery delta. The chosen farmers are Octogenarians,
inhabiting different parts of the Cauvery delta. I will record their life stories from the perspective of changing
climate, how they have adapted and the challenges they have faced. The questions asked will pertain to temperature
rise or decline, water quality and availability, change in crops sown, changing levels of silt deposits, coastal erosion
and how these have affected social relations, and findings curated accordingly (Adamson, Hannaford, and Rohland 2018; Singh 2019).
Description Our key finding in the research area was to prove using GIS that water tanks in the research region declined rapidly in the colonial era, and there is some potential to recuperate this form of water storage. reports of the Madras Presidency from 1910-1945. The RA focused on rainfall data and changing patterns of irrigation in the Kaveri river delta. This data was then analysed and presented in a series of graphs to display the changes in irrigation patterns and methods in the delta after the completion of the Mettur Dam in 1934. This dam increased canal irrigation which replaced more traditional methods such as tank irrigation. Much of this change is visible in Tanjore district.
the RA then put this data with some earlier GIS work completed concerned with tanks in South India and used geo-referenced historical maps to look at the changing waterscapes in Tanjore district. The RA selected tank features from the historical maps and compared them with satellite imagery to see how many tanks were still visible, and how many had been replaced by urbanisation, railways, roads, and canals.
Conclusion:The changing waterscapes and increased irrigation potential the new canals provided in Tanjore district were the result of the colonial government of the Madras presidency's drive to increase crop yields via a double cropping season and stimulating industrial development. This played a part in the abandonment of irrigation tanks and more traditional methods of water-management in the Kaveri river delta. The was presented as part of the ESRC social science festival, among other venues.
Exploitation Route The RA on the project is currently taking forward the data and outcomes as part of a PhD in the research region.
Sectors Agriculture, Food and Drink,Environment

Description Findings were used to author a popular piece on a recent bill passed to protect the 'environment' of the Cauvery delta - The article received wide traction on social media. Findings were used for further publications, including a talk for the ESRC Social Science Festival, a lengthy blog for the Institute for Historical Research, the creation of a data set from Season and Crop reports that spanned over 50 years.
First Year Of Impact 2020
Sector Agriculture, Food and Drink,Environment
Impact Types Policy & public services

Description British Academy Knowledge Frontiers Grant
Amount £3,800 (GBP)
Funding ID KFSSFKNAW\100011 
Organisation The British Academy 
Sector Academic/University
Country United Kingdom
Start 01/2021 
End 02/2022
Description ESRC Impact Acceleration Fund
Amount £700 (GBP)
Organisation Economic and Social Research Council 
Sector Public
Country United Kingdom
Start 11/2021 
End 11/2021
Title Cauvery delta: temperature and rainfall 
Description The data-set contains rainfall and temperature patterns for the Cauvery delta from 1880-1950, searchable by year and district. 
Type Of Material Data handling & control 
Year Produced 2021 
Provided To Others? No  
Impact The data-set is not yet publically available. 
Description Workshop/fieldtrip 
Organisation French Institute of Pondicherry
Country India 
Sector Charity/Non Profit 
PI Contribution French Institute of Pondicherry, Puducherry, India - Collaboration with Dr. Senthil Babu to host a conference titled 'People's report on political economy of the Cauvery delta' - PI facilitated a full day of the workshop, alongside fisherfolk and agriculturalist unions.
Collaborator Contribution - The French Institute of Pondicherry provided the space, sent invitations to several fishing and farming unions in the Cauvery delta for the workshop. - Dr. Senthil Babu, of the French Institute of Pondicherry organised a five day field visit to the Cauvery delta, assembling an interdisciplinary team of a photographer, public works engineer, a cooperative farmer, and a field ecologist.
Impact N/A (forthcoming project report)
Start Year 2019
Description Deltas after rice: agrarian pasts, environmental futures 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact An article titled 'Deltas after rice: agrarian pasts, environmental futures' for the Institute of Historical Research blog, which was a long 2000 word piece on why environmental history matters to the present.
Year(s) Of Engagement Activity 2021
Description ESRC social science festival (Life of water: a seminar) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Intended purpose was to showcase the research from the project, and make interested audiences aware of outputs including data and maps.
Year(s) Of Engagement Activity 2021
Description TN Govt's Bill to Protect Cauvery Delta Makes the Right Noises, Not Much Else 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Increased awareness of a law that would impact rice cultivation in study regions through the media.
Year(s) Of Engagement Activity 2020