Lake Victoria is a crucial ecosystem for ov er 25 million people in Kenya, Uganda, Tanzania, Rwanda and Burundi who live in the basin, and for the greater Nile river system downstream of the lake. Ecosystem management in the Lake Victoria basin has been highly extractive for most of the last 60 years, with the 1990s marking a period of decline in food production, economic contra ction, rising poverty, increased burden of human disease, and increased flood s. Lake Victoria itself is becoming eutrophic, with related proble ms of species extinctions and invasive species. Concepts and approaches from the Millenniu m Ecosystem Assessment were applied in a study of ecosystem service tradeoffs in two of th e river basins that flow into Lake Victoria from Kenya (Yala and Nyando). Hydrologic units are the main geographic unit for analysis, with flows of water and sediment acting as the main integrator of provisioning and regulating services. The SWAT hydrologic model is calibrated to baseline data for the watershed and used to simulate water avai lability, water use and runoff, and sediment movement across the watershed. Provisioning services are evaluated through a spatially- disaggregated analysis of agricultural produc tion, yield and area that combines spatial data from aerial photographs with divi sion-level price and yield estimates. The results illustrate large year-to-year variation in food supply, non-food agricultural production, sediment yield and flood risk in the two basins. The results indicate both synergies and tradeoffs between provisioning and regulating services, with results from the Yala basin much more consistent than fo r the Nyando. Simulation results show that conservation agriculture has potential to enhance regulating services in synergy with provisioning services. Policies conducive to smallholder agriculture and land conservation can generate greater synergies.
DOI:
https://doi.org/10.5716/WP15658.PDFAltmetric score:
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Publication year
2023
Authors
Swallow B M; Sang J K; Nyabenge M; Bondotich D; Yatich T T B; Duraiappah A K; Yashiro M
Language
English
Keywords
agriculture, conservation (storage), ecosystems
Geographic
Kenya
