Hope Mwanake1, Gabriel Stecher1, Bano Mehdi-Schulz1, Karsten Schulz1, Nzula Kitaka2, Luke Olang3, Mathew Herrnegger1
1Institute of Hydrology and Water Management (HyWa), University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
2Department of Biological Sciences, Egerton University, P.O. Box 536 – 20115 Egerton-Njoro, Kenya
3Department of Biosystems and Environmental Engineering, Technical University of Kenya, Nairobi, Kenya
Abstract
The complexity of shared governance, the variety of land use practices that affect water quantity and quality, and the fluctuating socioeconomic conditions that lead to different regional priorities are some of the reasons that pose particular challenges for sustainable resource management for transboundary river basins. This study carried out in the Sio Malaba Malakisi River Basin (SMMRB), shared by Kenya and Uganda, examines how combining a scientific evaluation of local soil erosion risk together with farmer-reported views of soil erosion and field conservation measures enhances soil conservation efforts.
Through participatory surveys involving 200 farming households to gather data on their estimations of soil loss, and on their farm management practices, together with the regional application of geospatial analysis to estimate soil erosion with the Universal Soil Loss Equation (USLE), we identified significant discrepancies between farmer perceptions and estimated USLE soil erosion outcomes. While 60% of farmers reported visible soil erosion and 92% noted declining soil fertility, the spatial modeling of the USLE estimates revealed that over 76% of the region lacks effective soil and water conservation practices (SWCPs), leaving vast areas vulnerable to erosion. These findings highlight a substantial gap between farmer perceptions and modeled estimates, emphasizing the need for targeted interventions. Furthermore, transboundary water quality assessments revealed nutrient "hotspots" linked to erosion, stressing the need for joint management strategies to address shared challenges.
To address these challenges, a Best Management Practices (BMPs) scenario was developed based on the knowledge of the 200 farmers interviewed within the basin and the practices of "best-practice farmers" from the survey results. This scenario assumes that farmers are more likely to adopt measures already practiced in their vicinity, such as terracing for steep slopes or crop rotation for maize and beans, reflecting local topography and cropping systems. The BMP scenario predicts a 25% reduction in severely eroded areas, demonstrating the transformative potential of scaling up the SWCPs to reduce soil loss. These outcomes reinforce the importance of leveraging local knowledge to design regionally relevant conservation strategies.
In this study, farmers expressed a strong willingness to share their insights on soil erosion and conservation, highlighting the need for community-driven conservation efforts that integrate farmer knowledge into scientific frameworks. These efforts can lead to more effective erosion control and sustainable land management by fostering a sense of ownership and encouraging locally informed decision-making.
This research highlights the need for data-driven, context-specific conservation strategies in data-scarce regions like the SMMRB, emphasizing the importance of local data, and farmer engagement for the adoption of BMPs. The results provide a scalable model for comparable data scarce areas around the world and highlight the significance of coordinated transboundary collaborations, and inclusive capacity-building balancing between ecosystem restoration and sustainable livelihoods.