Estimating nitrogen fluxes at the European scale by upscaling INTEGRATOR model outputs from selected sites

[摘要] A comparison was made between upscaled model results of nitrogen (N) fluxesto air and water from 450 sites within the EU-27 and results derived for theentire EU-27 area using the model INTEGRATOR. The 450 sites were selectedusing stratified random sampling, dividing the EU-27 into 150 strata andselecting three sites at random within each stratum. The strata were basedon important environmental factors influencing N fluxes. Hierarchicaldivisive cluster analysis was used to reduce the numerous combinations ofenvironmental factors to the required total of 150, such that theheterogeneity of environmental factors within strata was as small aspossible. Modelled NH₃, N₂O and NO_x emissions and Nleaching/runoff obtained were scaled up from the 450 sites to the entireEU-27 and were within 10% of results obtained by running the model for thewhole of the EU-27 using about 36 500 sites. This implies that a reliableestimate of N fluxes for EU-27 can be made by upscaling results of the 450selected sites suggesting that dramatic reduction in computation time can beachieved without substantial deterioration of results

[学科分类] 地球化学与岩石