Date of Award

Spring 2010

Project Type


Program or Major

Natural Resources: Water Resources

Degree Name

Master of Science

First Advisor

William H McDowell


Non point-source pollution from agricultural activity is a major cause of water quality degradation. In particular, nutrient loading can lead to eutrophication and related anoxia in rivers, streams and lakes. Floodplains adjacent to these water bodies are sites of active nutrient cycling that can mediate the flux of nutrients to and from these water bodies. This study examines the hydrologic and nutrient dynamics of an agriculturally-influenced creek and floodplain in Lee, New Hampshire. Chemical mixing models were used to assess cycling of nutrients in response to flooding. The floodplain acted primarily as a sink for phosphate (PO43-), ammonium (NH4+) and dissolved organic carbon (DOC) and nitrogen (DON), whereas there was minimal removal of nitrate (NO 3-). Nutrient dynamics were significantly impacted by groundwater interaction, hydroperiod and areal extent of flooding. The apparent lack of permanent removal pathways suggests that this floodplain only provides temporary nutrient storage.