Green Infrastructure and Ecosystem Services of the Kole Wetlands, Kerala: Implications for Disaster Risk Reduction
M. Sunilkumar
*
Dr. John Matthai Centre, University of Calicut, Kerala, India and PM Government College Chalakudy, Affiliated to University of Calicut, India.
T D. Simon
Research & PG Department of Economics, Sree Keralavarma College, Thrissur, Affiliated to University of Calicut, India.
*Author to whom correspondence should be addressed.
Abstract
Aims: The study aims to evaluate the role of green infrastructure as a provider of regulating ecosystem services for ecosystem-based disaster risk reduction (Eco-DRR) in the Kole wetlands of Kerala, with particular emphasis on flood mitigation during extreme rainfall events.
Study Design: The research adopts a mixed-methods design integrating hydrological assessment, ecological field observation, spatial analysis, and stakeholder-oriented qualitative inquiry within a socio-ecological systems framework.
Place and Duration of Study: The study was conducted in the Kole wetlands, a low-lying agro-wetland system spanning Thrissur and Malappuram districts of Kerala, India. Data were analysed for the period 2000–2023, with detailed assessment of major flood events, particularly the 2018 Kerala floods and post-flood years (2019–2022).
Methodology: Hydrological assessment was carried out using multi-source datasets, including rainfall records, flood water-level data, canal storage capacity, regulator operation records, digital elevation models, and satellite-derived flood extent. Field-based ecological observations examined soil characteristics, vegetation cover, and wetland morphology influencing water retention. Structured interviews and focus group discussions with farmers, water managers, and irrigation officials were conducted to assess traditional water management practices and governance mechanisms supporting flood regulation.
Results: Results indicate that the Kole wetlands function as a large-scale flood retention system capable of accommodating approximately 1–1.5 m of floodwater during extreme events, significantly reducing peak flood levels compared to surrounding non-wetland areas. Canal networks and regulators facilitated controlled water distribution and gradual drainage, leading to a reduction in peak discharge by up to 35–40 percent and shorter flood recession periods. Agricultural damage within the wetlands was substantially lower than in adjacent areas, demonstrating effective disaster risk reduction.
Conclusion: The study concludes that the Kole wetlands operate as an integrated green infrastructure system delivering critical regulating ecosystem services for Eco-DRR. Strengthening wetland conservation, traditional water governance, and hybrid green–grey infrastructure approaches is essential for enhancing flood resilience and climate adaptation in vulnerable wetland landscapes.
Keywords: Ecosystem-based Disaster Risk Reduction, green infrastructure, regulating ecosystem services, Kole wetlands, flood mitigation, climate resilience