Chantal Hendriks, Harry Gibson, Anna Trett, Andre Python, Daniel Weiss, Anton Vrieling, Michael Coleman, Peter Gething, Penny Hancock, Catherine Moyes

The application of agricultural pesticides in Africa has high negative effects on human health and the environment. To analyse the effect, spatial data characterizing the environmental fate of agricultural pesticides are needed. However, poor availability and quality of data that quantify pesticide application and pesticide fate limit direct analysis of the effect. This study selected key geospatial processes affecting the environmental fate of agricultural pesticides utilizing pesticide fate models and modelled the spatial variation of each process using existing geospatial databases. Maps associated with leaching, surface runoff, sedimentation, soil storage and filtering capacity, and volatilization were created using existing geospatial datasets and, if applicable, existing methods. The potential and limitations of the created maps were discussed. An insecticide residue database was created to test the maps. The database contains 10,076 observations, but only limited number of observations remain when extracting a standard dataset for one compound. This study provided a complete set of key processes affecting pesticide fate that can be used in the identification of areas vulnerable to pesticide accumulation. The created maps have potential when used in combination with data on pesticide application or, when it is known which pesticides a crop receives, data on agricultural land use.