Uncertainties in model predictions of nitrogen fluxes from agro-ecosystems in Europe

[摘要] To assess the responses of nitrogen and greenhouse gas emissions topan-European changes in land cover, land management and climate, anintegrated dynamic model, INTEGRATOR, has been developed. This modelincludes both simple process-based descriptions and empirical relationshipsand uses detailed GIS-based environmental and farming data in combinationwith various downscaling methods. This paper analyses the propagation ofuncertainties in model inputs and parameters to outputs of INTEGRATOR, usinga Monte Carlo analysis. Uncertain model inputs and parameters wererepresented by probability distributions, while spatial correlation in theseuncertainties was taken into account by assigning correlation coefficientsat various spatial scales. The uncertainty propagation was analysed for theemissions of NH₃, N₂O and NO_x, N leaching to groundwater andN runoff to surface water for the entire EU27 and for individual countries.Results show large uncertainties for N leaching and runoff (relative errorsof ∼ 19% for Europe as a whole), and smaller uncertainties foremission of N₂O, NH₃ and NO_x (relative errors of ∼ 12%). Uncertainties for Europe as a whole were much smaller compared touncertainties at country level, because errors partly cancelled out due tospatial aggregation.

[学科分类] 地球化学与岩石