Hydrological mediated denitrification in groundwater below a seasonal flooded restored riparian zone

Jannick Kolbjørn Jensen, Peter Engesgaard, Anders R. Johnsen, Vicens Marti, Bertel Nilsson

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

A restored riparian zone was characterized to understand the effects of flooding on subsurface hydrological flow paths and nitrate removal in groundwater. Field and laboratory investigations were combined with numerical modeling of dynamic flow and reactive nitrate transport. Flooding enhances nitrate removal in groundwater primarily by two mechanisms. First, by creating a stagnant flow zone beneath the flooded area thereby increasing the residence time and leaving more time for nitrate removal. Secondly, nitrate removal is increased by enhancing upward flow into the highly reactive organic-rich top layers. Flooding therefore contributes to nitrate removal in “hot spots”, where nitrate is transported to the peat and during “hot moments”, when flow is stagnant. The permeability of the capping peat layer relative to the aquifer is important as it controls both mechanisms. The model shows that the deep-seated nitrate removal is greater than projected from the laboratory nitrate reduction experiments.

Original languageEnglish
Pages (from-to)2074-2094
Number of pages21
JournalWater Resources Research
Volume53
Issue number3
DOIs
Publication statusPublished - 1 Mar 2017

Keywords

  • Denitrification
  • Flooding
  • Hot moments
  • Hot spots
  • Riparian zones

Programme Area

  • Programme Area 2: Water Resources

Fingerprint

Dive into the research topics of 'Hydrological mediated denitrification in groundwater below a seasonal flooded restored riparian zone'. Together they form a unique fingerprint.

Cite this