TY - JOUR
T1 - Drainage and nutrient attenuation in a riparian interception-wetland
T2 - Southern Minnesota, USA
AU - Magner, Joe
AU - Alexander, Scott
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/6
Y1 - 2008/6
N2 - Riparian wetlands have multiple source waters that require understanding to effectively manage water quantity and quality. Source waters were determined in an interception-wetland located a relatively flat clayey till terrain in southern Minnesota. Data loggers were used to measure precipitation, water stage from monitoring wells and a tile-drain outlet. Over 70 oxygen (δ18O), hydrogen (δD) and geochemical water samples were collected from seven locations over different seasons (9 events) from 1996 to 1999. Results indicate the dominant source water input to the wetland was drained shallow groundwater beneath intensively managed cropland (P = 0.000). Evapotranspiration was the dominant export pathway. Nitrate-nitrogen (NO 3-N) concentrations significantly decreased (P = 0.000) in the cattail-willow portion of the wetland. Total phosphorous (TP) concentrations were relatively high in the grass portion of the wetland (673 ± 549 μg L-1), and relatively low in the cattail-willow portion of the wetland (139 ± 85 μg L-1) because source waters were low in TP. Overall, the interception-wetland design limited out-of-bank flooding, yet allowed sufficient gradient between the cropland and the wetland outlet to minimize potential crop damage and provide hydraulic storage for nutrient attenuation.
AB - Riparian wetlands have multiple source waters that require understanding to effectively manage water quantity and quality. Source waters were determined in an interception-wetland located a relatively flat clayey till terrain in southern Minnesota. Data loggers were used to measure precipitation, water stage from monitoring wells and a tile-drain outlet. Over 70 oxygen (δ18O), hydrogen (δD) and geochemical water samples were collected from seven locations over different seasons (9 events) from 1996 to 1999. Results indicate the dominant source water input to the wetland was drained shallow groundwater beneath intensively managed cropland (P = 0.000). Evapotranspiration was the dominant export pathway. Nitrate-nitrogen (NO 3-N) concentrations significantly decreased (P = 0.000) in the cattail-willow portion of the wetland. Total phosphorous (TP) concentrations were relatively high in the grass portion of the wetland (673 ± 549 μg L-1), and relatively low in the cattail-willow portion of the wetland (139 ± 85 μg L-1) because source waters were low in TP. Overall, the interception-wetland design limited out-of-bank flooding, yet allowed sufficient gradient between the cropland and the wetland outlet to minimize potential crop damage and provide hydraulic storage for nutrient attenuation.
KW - Agricultural drainage
KW - Interception-wetland
KW - Nutrient attenuation
KW - Stable isotopes
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U2 - 10.1007/s00254-007-0918-0
DO - 10.1007/s00254-007-0918-0
M3 - Article
AN - SCOPUS:43549086671
SN - 0943-0105
VL - 54
SP - 1367
EP - 1376
JO - Environmental Geology
JF - Environmental Geology
IS - 7
ER -