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Influences of catchment characteristics on nitrogen concentration in largely forested streams during the base flow period
Author(s) -
Su Baolin,
Kazama So,
Katayama Seiichiro,
Sawamoto Masaki
Publication year - 2006
Publication title -
hydrological processes
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.222
H-Index - 161
eISSN - 1099-1085
pISSN - 0885-6087
DOI - 10.1002/hyp.6181
Subject(s) - normalized difference vegetation index , base flow , hydrology (agriculture) , nitrogen , environmental science , drainage basin , streams , vegetation (pathology) , nitrate , growing season , ecology , chemistry , geology , geography , leaf area index , biology , medicine , computer network , cartography , geotechnical engineering , organic chemistry , pathology , computer science
Based on measured stream nitrogen concentrations at outlets of 12 small sub‐areas (1·3–54·7 km 2 ) in a largely forested catchment during the base flow period, we investigated the influences of discharges and different catchment characteristics on stream nitrogen concentration. Our field surveys were carried out during the 11‐month's period from April 2001 to February 2002 and the correlations between nitrogen concentrations and catchment characteristics were studied. The results showed that the vegetation cover was strongly correlated to total nitrogen (TN) and nitrate + nitrite − nitrogen (NO x ‐N) concentrations. That is, the TN and NO x ‐N concentrations had positive correlations with mean normalized difference vegetation cover index (NDVI) of each sub‐area during dormant seasons (mean NDVI < 0 · 70) and had negative correlations during the growing season (mean NDVI ≥ 0 . 70). The significance of catchment characteristics to TN and NO x ‐N concentrations was ranked as vegetation cover > soil > topography > land use, and the best models can account for 55–64% of the variance of TN and NO x ‐N concentrations. Copyright © 2006 John Wiley & Sons, Ltd.