中国海洋湖沼学报（英文版）2012，Vol.30Issue(4)：654-667,14.
Nitrogen budget in the Changjiang River drainage area
Nitrogen budget in the Changjiang River drainage area
摘要
Abstract
We established a budget model of nitrogen (N) inputs and outputs between watersheds and waterbodies to determine the sources of riverine N in the Changjiang (Yangtze) River drainage area.Nitrogen inputs in the budget included N from synthetic fertilizer,biological fixation by leguminous and other crops,wet/dry atmospheric deposition,excreta from humans and animals,and crop residues.The total N input was estimated to be 17.6 Tg,of which 20％ or 3.5 Tg N was transported into waterbodies.Of the total N transported into waterbodies,the largest proportion was N from animal waste (26％),followed by N from atmospheric wet/dry deposition (25％),synthetic fertilizer N (17％),N in sewage wastes (17％),N in human waste from rural areas (6％) and industrial wastewater N (9％).We studied the spatial patterns of N inputs and outputs by dividing the Changjiang River drainage area into four sub-basins,from upstream to downstream:the Tongtian River drainage area (TTD,the headwater drainage area,138 000 km2,less disturbed by human activities); the Jinsha River drainage area (JSD,347 000 km2,less disturbed by human activities,approx.3 500 km upstream of the Changjiang estuary); the Pingshan-Yichang drainage area (PYD,520 500 km2,large-scale human disturbance,about 2 000 km upstream of the Changjiang estuary);and the Yichang-Datong drainage area (YDD,699 900 km2,large-scale human disturbance,approx.620 km upstream of the Changjiang estuary).The average N input into waterbodies was 2.3,7.3,24.1,and 28.2 kg N/ha in the TTD,JSD,PYD,and YDD sub-basins,respectively,suggesting an increase of N-components of more than 10 times from upstream to downstream areas.关键词
nitrogen budget/eutrophication/Changjiang (Yangtze) River drainage area/riverine nitrogen transportKey words
nitrogen budget/eutrophication/Changjiang (Yangtze) River drainage area/riverine nitrogen transport引用本文复制引用
JIANG Tao,YU Zhiming,SONG Xiuxian,CAO Xihua..Nitrogen budget in the Changjiang River drainage area[J].中国海洋湖沼学报（英文版）,2012,30(4):654-667,14.基金项目
Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-Q07-02),the National Basic Research Program of China (973 Program) (No.2010CB428706),the Fund for Creative Research Groups of NSFC (No.41121064),and the National Natural Science Foundation of China (No.41106090) （No.KZCX2-YW-Q07-02）
