A new paper by Ecohydrology group researchers titled "Effects of damming on river nitrogen fluxes: A global analysis" was published this week in Global Biogeochemical Cycles. The paper quantifies the impact of dams on global riverine nitrogen fluxes using a reservoir nitrogen (N) mass balance model. The model accounts for nitrogen elimination by burial in reservoir sediments and gaseous emissions to the atmosphere through denitrification. Additionally, the addition of nitrogen to reservoirs via nitrogen fixation is considered in the model. The model is scaled up to the global scale using Monte Carlo analysis. The results demonstrate that denitrification and burial in reservoirs eliminated 7% of N loading to the global river network in 2000 that is predicted to double by 2030, mainly because of the current boom in dam building. By coupling our results to those of our earlier work on phosphorus (P), we further show that dams increase the N:P ratio of riverine discharge, hence reducing the magnitude of N limitation of primary production in receiving lentic and coastal marine environments.
To read the paper, click here.