Skip to main content

page search

Library Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

Assessment of global nitrogen pollution in rivers using an integrated biogeochemical modeling framework

Resource information

Date of publication
December 2011
Resource Language
ISBN / Resource ID
AGRIS:US201500010751
Pages
2573-2586

This study has analyzed the global nitrogen loading of rivers resulting from atmospheric deposition, direct discharge, and nitrogenous compounds generated by residential, industrial, and agricultural sources. Fertilizer use, population distribution, land cover, and social census data were used in this study. A terrestrial nitrogen cycle model with a 24-h time step and 0.5° spatial resolution was developed to estimate nitrogen leaching from soil layers in farmlands, grasslands, and natural lands. The N-cycle in this model includes the major processes of nitrogen fixation, nitrification, denitrification, immobilization, mineralization, leaching, and nitrogen absorption by vegetation. The previously developed Total Runoff Integrating Pathways network was used to analyze nitrogen transport from natural and anthropogenic sources through river channels, as well as the collecting and routing of nitrogen to river mouths by runoff. Model performance was evaluated through nutrient data measured at 61 locations in several major world river basins. The dissolved inorganic nitrogen concentrations calculated by the model agreed well with the observed data and demonstrate the reliability of the proposed model. The results indicate that nitrogen loading in most global rivers is proportional to the size of the river basin. Reduced nitrate leaching was predicted for basins with low population density, such as those at high latitudes or in arid regions. Nitrate concentration becomes especially high in tropical humid river basins, densely populated basins, and basins with extensive agricultural activity. On a global scale, agriculture has a significant impact on the distribution of nitrogenous compound pollution. The map of nitrate distribution indicates that serious nitrogen pollution (nitrate concentration: 10–50 mg N/L) has occurred in areas with significant agricultural activities and small precipitation surpluses. Analysis of the model uncertainty also suggests that the nitrate export in most rivers is sensitive to the amount of nitrogen leaching from agricultural lands.

Share on RLBI navigator
NO

Authors and Publishers

Author(s), editor(s), contributor(s)

He, Bin
Kanae, Shinjiro
Oki, Taikan
Hirabayashi, Yukiko
Yamashiki, Yosuke
Takara, Kaoru

Publisher(s)
Data Provider