Abstract

Denitrification is the main process removing nitrate in river drainage basins and buffer input from agricultural land and limits aquatic ecosystem pollution. However, the identification of denitrification hotspots (for example, riparian zones), their role in a landscape context and the evolution of their overall removal capacity at the drainage basin scale are still challenging. The main approaches used (that is, mass balance method, denitrification proxies, and potential wetted areas) suffer from methodological drawbacks. We review these approaches and the key frameworks that have been proposed to date to formalize the understanding of the mechanisms driving denitrification: (i) Diffusion versus advection pathways of nitrate transfer, (ii) the biogeochemical hotspot, and (iii) the Damkohler ratio. Based on these frameworks, we propose to use high-resolution mapping of catchment topography and landscape pattern to define both potential denitrification sites and the dynamic hydrologic modeling at a similar spatial scale (< 10 km(2)). It would allow the quantification of cumulative denitrification activity at the small catchment scale, using spatially distributed Damkohler and Peclet numbers and biogeochemical proxies. Integration of existing frameworks with new tools and methods offers the potential for significant breakthroughs in the quantification and modeling of denitrification in small drainage basins. This can provide a basis for improved protection and restoration of surface water and groundwater quality.

Keywords

denitrification; biogeochemical hotspot; upscaling; residence time distribution; Damkohler ratio; diffuse pollution control

Published in

Ecosystems
2015, Volume: 18, number: 6, pages: 1101-1120
Publisher: SPRINGER

SLU Authors

• Bishop, Kevin

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use
Oceanography, Hydrology, Water Resources
Geochemistry


Publication identifier

DOI: https://doi.org/10.1007/s10021-015-9878-5

Permanent link to this page (URI)

https://res.slu.se/id/publ/73439