The N-Sink approach is based off of research outlined in
Kellogg et al (2010).
This approach builds on peer-reviewed literature in the form of reviews and
meta-analyses (i.e., Mayer et
al (2007), Alexander
et al (2007), and
Seitzinger
et al (2006)) to estimate nitrogen (N) removal within three types of
landscape sinks -- wetlands, streams and lakes -- along any given flow path
within a HUC12 basin. The nsink package implements this approach,
using publicly available spatial data to identify flow paths and estimate N
removal in landscape sinks. Removal rates depend on retention time, which is
influenced by physical characteristics identified using publicly available
spatial data -- National Hydrography Dataset (NHD), Watershed Boundary
Dataset (WBD), National Land Cover Dataset (NLCD), and Soil Survey Geographic
Dataset (SSURGO). Static maps of a specified HUC-12 basin are generated -- N
Removal Efficiency, N Loading Index, N Transport Index, and N Delivery Index.
These maps may be used to inform local decision-making by highlighting areas
that are more prone to N "leakiness" and areas that contribute to N removal.
References
Kellogg, D. Q., Gold, A. J., Cox, S., Addy, K., & August, P. V. (2010). A geospatial approach for assessing denitrification sinks within lower-order catchments. Ecological Engineering, 36(11), 1596-1606. Link
Mayer, P. M., Reynolds Jr., S. K., McCutchen, M. D., & Canfield, T. J. (2007). Meta-analysis of nitrogen removal in riparian buffers. J. Environ. Qual. 36, 1172-1180. Link
Alexander, R. B., Boyer, E. W., Smith, R.A., Schwarz, G.E. & Moore, R. B. (2007). The role of headwater streams in downstream water quality. J. Am. Water Resou.Assoc. 43, 41-59. Link
Seitzinger, S. P., Harrison, J.A., Hohlke, J.K., Bouwman, A.F., Lowrance, R., Peterson, B., Tobias, C., & Van Drecht, G. (2006). Denitrification across landscapes and waterscapes: a synthesis. Ecol. Appl. 16, 1064-2090. Link