Novel geochemistry to determine the dynamics of land to lake transfers in the Lake Victoria basin to inform coordinated land-lake management strategies

The Winam Gulf catchment of Lake Victoria in western Kenya has historically been affected by poor land management practices leading to soil erosion, acidification and loss of organic matter. A gap in data exists to better understand the influence of soil degradation on soil-to-crop dynamics for micronutrients essential for a healthy diet. Additionally, the transfer of potentially toxic elements from land-to-lake via sediment flows and dust transfer has consequences for the lake ecosystem and human health via the food chain. Here we present geochemical data to demonstrate soil-to-sediment transfers from agricultural and urban environments for initial source apportionment analyses and reference to historical sediment inflows into the Winam Gulf from major river catchments that contribute up to 25% of total sediment inflows for the whole of Lake Victoria. Detailed geochemistry will build on previous work to model soil erosion/geochemistry in western Kenya1,2 to better inform the management of agricultural soils to reduce loss of productivity and lake ecology for the fisheries industry. Both are crucial to food security and livelihoods as key United Nations Sustainable Deliverables Goals (SDG 2,3,14) in the region, by helping to connect land and lake management stakeholders for a coordinated mitigation plan to address poor land-use management. These data are presented alongside consortia presentations detailing highly specialised chemistry using plutonium isotopes to measure the rate of soil erosion, modelling at scale soil-to-crop transfers of nutrients and changes in soil chemistry according to land clearance and farming mitigation approaches. References: 1 Humphrey et al. (2022). Evaluating spatio-temporal soil erosion dynamics in the Winam Gulf catchment, Kenya for enhanced decision making in the land-lake interface, STOTEN, 815, 151975 https://doi.org/10.1016/j.scitotenv.2021.151975 2 Ferreira et al. (2022). Western Soil geochemistry predictive map https://arcg.is