Journal article
Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness
Journal of environmental quality, Vol.44(6), pp.1754-1763
11/2015
DOI: 10.2134/jeq2015.02.0105
PMID: 26641327
Abstract
Strategies to reduce nitrate‐nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443‐ha Bear Creek watershed in north‐central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m−1 (7.6 mi−1) to 0.04 m−1 (62 mi−1), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile‐drained watersheds.
Core Ideas
Mean groundwater travel times are significantly reduced with increasing tile drainage.
Drainage density increased with expansion of the tile drainage network.
Tile drainage reduces potential for denitrification in the watershed.
Details
- Title: Subtitle
- Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness
- Creators
- Keith E. Schilling - University of IowaCalvin F. Wolter - Iowa Department of Natural ResourcesThomas M. Isenhart - Iowa State UniversityRichard C. Schultz - Iowa State University
- Resource Type
- Journal article
- Publication Details
- Journal of environmental quality, Vol.44(6), pp.1754-1763
- Publisher
- The American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc
- DOI
- 10.2134/jeq2015.02.0105
- PMID
- 26641327
- ISSN
- 0047-2425
- eISSN
- 1537-2537
- Number of pages
- 10
- Grant note
- Leopold Center for Sustainable Agriculture (E2009‐16)
- Language
- English
- Date published
- 11/2015
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984383911102771
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