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Distributed topographic indicators for predicting nitrogen export from headwater catchments
Author(s) -
Creed I. F.,
Beall F. D.
Publication year - 2009
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2008wr007285
Subject(s) - environmental science , hydrology (agriculture) , nitrate , nitrogen , watershed , streams , physical geography , geography , geology , ecology , biology , computer network , machine learning , computer science , physics , geotechnical engineering , quantum mechanics
The possibility of using topographic indicators to predict spatial variation in dissolved nitrogen (N) export from headwater catchments was explored within a sugar maple forest in the Algoma Highlands of central Ontario, Canada, where the average annual export of total dissolved N export ranged from 3.58 to 6.96 kg N ha −1 a −1 . Topographic indicators representing both “nondistributed” and “distributed” properties of the catchments were derived. Distributed topographic indicators that were designed to represent hydrologic flushing mechanism for N export were superior in predicting nitrate‐N export, explaining up to 85% in average annual nitrate‐N export and 90% in the slope of discharge versus peak nitrate‐N export which occurred during spring melt. However, the distributed topographic indicators were comparable to nondistributed ones for dissolved organic nitrogen export, explaining up to 68% of the variance compared to 65%. This study shows that spatial variation in N export from catchments within a relatively small region can be substantial, but that distributed topographic indicators can be used to predict a majority of this N export and thereby provide a basis for extrapolating N export from a few intensively monitored catchments to many other catchments within the sugar maple forest of the Algoma Highlands.