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The hydrology of a drained topographical depression within an agricutlural field in north-central Iowa

Transactions of the American Society of Agricultural and Biological Engineers

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Abstract

North-central Iowa is an agriculturally intensive area comprising the southeastern portion of the Prairie Pothole Region, a landscape containing a high density of enclosed topographical depressions. Artificial drainage practices have been implemented throughout the area to facilitate agricultural production. Vertical surface drains are utilized to drain the topographical depressions that accumulate water. This study focuses on the hydrology of a drained topographical depression located in a 39.5 ha agricultural field. To assess the hydrology of the drained depression, a water balance was constructed for 11 ponding events during the 2008 growing season. Continuous pond and groundwater level data were obtained with pressure transducers. Flows into the vertical surface drain were calculated based on pond depth. Precipitation inflows and evaporative outflows of the ponds were calculated using climatic data. Groundwater levels were used to assess groundwater/pond interactions. Results of the water balances show distinct differences between the inflows to and outflows from the depression based on antecedent conditions. In wet conditions, groundwater inflow sustained the ponds. The ponds receded only after the groundwater level declined to below the land surface. In drier conditions, groundwater was not a source of water to the depression. During these drier conditions, infiltration comprised 30% of the outflows from the depression during declining pond stages. Over the entire study period, the surface drain, delivering water to the stream, was the largest outflow from the pond, accounting for 97% of the outflow, while evapotranspiration was just 2%. Precipitation onto the pond surface proved to be a minor component, accounting for 4% of the total inflows.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The hydrology of a drained topographical depression within an agricutlural field in north-central Iowa
Series title:
Transactions of the American Society of Agricultural and Biological Engineers
Volume
55
Issue:
5
Year Published:
2012
Language:
English
Publisher:
American Society of Agricultural and Biological Engineers
Publisher location:
St. Joseph, MI
Contributing office(s):
Minnesota Water Science Center
Description:
15 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Transactions of the American Society of Agricultural and Biological Engineers
First page:
1801
Last page:
1814
Country:
United States
State:
Iowa