Community views on tree-based flood mitigation approach in the Nyamwamba catchment, Uganda

Abstract

The Nyamwamba catchment in Kasese District, Uganda, has experienced recurrent and severe flash flooding, which has significantly compromised local livelihoods, agricultural productivity, and public infrastructure. This ongoing environmental vulnerability forms the core problem investigated in this study, with a specific focus on understanding community engagement in tree planting as a sustainable nature-based solution for flood risk management. To provide a comprehensive assessment, the research was structured around three specific objectives: first, to characterize the existing tree planting activities within the catchment; second, to examine the socio-economic and environmental determinants that shape community perceptions and dictate active local participation; and third, to evaluate how local people experience and perceive the overall practical effectiveness of these treebased interventions in mitigating flood disasters. The study adopted a cross-sectional research design employing a mixed-methods approach to collect and analyze both quantitative and qualitative data simultaneously. Primary data was gathered using simple random sampling to administer structured questionnaires to 73 household respondents across flood-affected zones, alongside purposive sampling to conduct interviews with 7 targeted key informants and facilitate two focus group discussions. Quantitative data obtained from the field was systematically coded and analyzed using descriptive statistical methods, specifically focusing on frequencies and percentages. Complementarily, qualitative data from the interviews and discussions was processed using manual thematic analysis to capture and contextualize detailed community narratives and institutional experiences. The results of the study, analyzed sequentially by objective, reveal that while environmental awareness is high, structural barriers heavily dictate the actual success of nature-based interventions. According to the first objective, which characterized tree planting activities, the findings showed that a significant majority (89.04%) of the respondents were highly aware of tree planting initiatives designed for flood mitigation. These activities are primarily distributed along vulnerable riverbanks, private farmland boundaries, and public institutional lands using species such as bamboo and grevillea; however, their initial growth and survival are severely threatened by poor soil quality and localized wildlife destruction. Concerning the second objective, which examined the socio-economic and environmental determinants of community participation, the study established that although community willingness and practical skill confidence were high (82.19%), actual implementation is heavily constrained by structural barriers. Chief among these determinants is limited land availability, affecting 71.43% of the targeted areas due to small-scale subsistence farming needs, alongside ongoing soil erosion (57.14%) and restricted access to high-quality, floodresistant seedlings (42.86%). Finally, under the third objective evaluating local perspectives on overall effectiveness, the community expressed highly realistic but divided experiences. While 63.01% of the respondents believe that tree planting possesses the theoretical capacity to reduce flood risks by stabilizing topsoil, 54.79% reported that intense flash flood events frequently wash away or completely destroy younger tree stands and seedlings. Consequently, the local population views tree planting as an insufficient standalone strategy, emphasizing those nature-based solutions must be integrated with hard structural engineering interventions to effectively safeguard the catchment. Conclusion: While community members strongly recognize the potential ecological and economic benefits of tree planting for flood mitigation, significant structural barriers and environmental vulnerabilities must be addressed to enhance long-term sustainability. The study underscores the importance of integrating local knowledge and addressing socioeconomic constraints, such as land scarcity and seedling availability, to foster deeper community engagement. Based on these insights, it is recommended that policymakers and environmental managers enhance targeted education programs, introduce subsidized high quality seedlings, and crucially, combine biological tree planting methods with structural engineering measures like riverbank reinforcement and mechanical desiltation to achieve long-term catchment resilience.