Impact of Climate Change on Paddy Farming in the Village Tank Cascade Systems of Sri Lanka

• Published in: Sustainability 2023-06, Vol.15 (12), p.9271
• Main Authors: Ratnayake, Sujith S, Reid, Michael, Larder, Nicolette, Kadupitiya, Harsha K, Hunter, Danny, Dharmasena, Punchi B, Kumar, Lalit, Kogo, Benjamin, Herath, Keminda, Kariyawasam, Champika S
• Format: Article
• Language: English
• Subjects: Agricultural industry; Agricultural production; Agriculture; Analysis; Anomalies; Book publishing; Climate change; Climate models; Climate prediction; Climate variability; Crop production; Cultivation; Ecosystems; Farming; Food; Geomorphology; Global climate models; Global warming; Harvest; Hydrologic data; Intergovernmental Panel on Climate Change; Precipitation variability; Productivity; Rain; Rain and rainfall; Rainfall; Seasonal variations; Social interactions; Sustainability; Trends; Variability; Water shortages; Water supply; Wind
• ISSN: 2071-1050; 2071-1050
• DOI: 10.3390/su15129271

Consequences of global climate change are predicted to increase risks to crop production in the future. However, the possible broader impact of climate change on social-ecological systems still needs to be evaluated. Therefore, the present study focuses on one such globally important agricultural social-ecological system referred to as the Village Tank Cascade System (VTCS) in the dry zone of Sri Lanka. The VTCS has considerable potential to withstand seasonal climate variability mainly through continuous supply of water by the village tank storage throughout the year. The current study aimed to investigate trends of climate variability and possible impacts on paddy production in the North and North-central VTCS zone. Observed and projected rainfall and temperature data were analysed to evaluate the past variability trends (1970 to 2020) and model future (up to 2100) scenarios of climate variability and trends. Long-term observed rainfall and temperature data (1946 to 2020) were analysed to identify possible anomalies. The Maximum Entropy (MaxEnt) model has been used to predict the situation of future paddy farming (2050 and 2070) under two climate scenarios (RCP4.5 and RCP8.5) of the Intergovernmental Panel on Climate Change (IPCC). Six variables that would affect paddy growth and yield quality were used alongside the average monthly rainfall and temperature of two Global Climate Models (MIROC5 and MPI-ESM-LR). Climate suitability for two paddy cultivation seasons (Yala and Maha) were predicted for current and future climate scenarios. The findings revealed that observed and projected climate changes show considerable deviation of expected rainfall and temperature trends across the VTCS zone. Temperature exhibits warming of approximately 1.0 °C during the declared Global Warming Period (1970 to 2020) in the study area. In addition, there is a trend of significant warming by 0.02 °C/year, RCP4.5 and 0.03 °C/year, RCP8.5 from 1950 to 2100. Rainfall (1970–2020) shows high interannual variability but trends were not significant and less discernible. However, long-term projected rainfall data (1950–2100) analysis detected a significant (p = 0) upward trend (2.0 mm/year, RCP4.5 and 2.9 mm/year, RCP8.5), which is expected to continue up to the end of this century. Further, the study revealed some shifts in temperature towards higher values and positive anomalies in rainfall affecting seasonality and the likelihood of more extreme occurrences in the future, espec