Experimental and modelling evidence of splash effects on manure borne Escherichia coli washoff

In tropical montane South-East Asia, recent changes in land use have induced increased runoff, soil erosion and in-stream suspended sediment loads. Land change is also contributing to microbial pathogen dissemination contamination of stream waters. Escherichia coli (E. coli) frequently used as an indicator faecal contamination. Field rain simulations were conducted examine how E. exported from the surface upland, agricultural soils during runoff events. The objectives characterize loss dynamics this contaminated with livestock waste, identify effect splash on washoff. Experiments performed nine 1 m2 plots, amended or not pig poultry manure. Each plot was divided into two 0.5 sub-plots. One sub-plots protected a mosquito net for limiting raindrop impact effects. Runoff, detachment by its entrainment loads discharge measured each sub-plot. results show that strongly enhances generation, export. When raindrops reduced net, total more than 50%, average 90% export 3 8 times lower. A coupled physics-based approach using Cast3M platform modelling time evolutions solid particles transfer bacteria transport one plots. After estimation saturated hydraulic conductivity, erodibility attachment rate bacteria, model outputs consistent coefficients, This work therefore underlines need maintain adequate vegetation at avoid borne potential pathogens towards downstream aquatic systems.