Increasing anthropogenic nitrogen inputs and riverine DIN exports from the Changjiang River basin under changing human pressures
Article first published online: 24 APR 2010
Copyright 2010 by the American Geophysical Union.
Global Biogeochemical Cycles
Volume 24, Issue 4, December 2010
How to Cite
2010), Increasing anthropogenic nitrogen inputs and riverine DIN exports from the Changjiang River basin under changing human pressures, Global Biogeochem. Cycles, 24, GB0A06, doi:10.1029/2009GB003575., , , , and (
- Issue published online: 24 APR 2010
- Article first published online: 24 APR 2010
- Manuscript Accepted: 16 NOV 2009
- Manuscript Revised: 21 SEP 2009
- Manuscript Received: 22 MAY 2009
- DIN model;
- Changjiang River;
- human activity
 In this paper, we estimate the inputs of nitrogen (N) and exports of dissolved inorganic nitrogen (DIN) from the Changjiang River to the estuary for the period 1970–2003, by using the global NEWS-DIN model. Modeled DIN yields range from 260 kg N km−2 yr−1 in 1970 to 895 kg N km−2 yr−1 in 2003, with an increasing trend. The study demonstrated a varied contribution of different N inputs to river DIN yields during the period 1970–2003. Chemical fertilizer and manure together contributed about half of the river DIN yields, while atmospheric N deposition contributed an average of 21% of DIN yields in the period 1970–2003. Biological N fixation contributed 40% of DIN yields in 1970, but substantially decreased to 13% in 2003. Point sewage N input also showed a decreasing trend in contribution to DIN yields, with an average of 8% over the whole period. We also discuss possible future trajectories of DIN export based on the Global NEWS implementation of the Millennium Ecosystem Assessment scenarios. Our result indicates that anthropogenically enhanced N inputs dominate and will continue to dominate river DIN yields under changing human pressures in the basin. Therefore, nitrogen pollution is and will continue to be a great challenge to China.