Event Title

Hydrologic and nutrient fluxes in a small watershed with changing agricultural practices

Presentation Abstract

Many watersheds feeding the Salish Sea are subject to nonpoint-source inputs of nutrients from agricultural activities, contributing to eutrophication of surface waters. The magnitude of these inputs is in turn dependent on the specific agricultural management strategies employed in the surrounding landscape. I investigated the impact of rapid changes in crop type and management on nutrient fluxes through the watershed of upper Kamm Creek, in northwest Washington State. I measured streamflow and the concentrations of various forms of nitrogen and phosphorous between October 2015 and October 2017, and compared these measurements against data from a previous water quality study conducted from 1993-1998 on the same watershed. I found significantly higher nitrate fluxes, and significantly lower fluxes for both forms of phosphorous, compared to the 1993-1998 sampling period. The relationships of all nutrient concentrations to streamflow was similar between sampling periods: nitrate concentrations decreased with streamflow, and phosphate and total phosphorous concentrations increased. Annual streamflow did not change compared to the previous sampling period, however streamflow was significantly higher during current summer months. Similar results were not found on the nearby Nooksack River, which receives water from the study stream. Changes in nutrient fluxes and streamflow on upper Kamm Creek may be associated with regional or local shifts in land management strategies. Linking specific land management changes with nutrient flux shifts is essential for planners trying to balance local agricultural and environmental interests, and deserves further investigation.

Session Title

Posters: Transboundary Management & Policy

Conference Track

SSE18: Posters

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE18-125

Start Date

5-4-2018 11:30 AM

End Date

5-4-2018 1:30 PM

Type of Presentation

Poster

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 5th, 11:30 AM Apr 5th, 1:30 PM

Hydrologic and nutrient fluxes in a small watershed with changing agricultural practices

Many watersheds feeding the Salish Sea are subject to nonpoint-source inputs of nutrients from agricultural activities, contributing to eutrophication of surface waters. The magnitude of these inputs is in turn dependent on the specific agricultural management strategies employed in the surrounding landscape. I investigated the impact of rapid changes in crop type and management on nutrient fluxes through the watershed of upper Kamm Creek, in northwest Washington State. I measured streamflow and the concentrations of various forms of nitrogen and phosphorous between October 2015 and October 2017, and compared these measurements against data from a previous water quality study conducted from 1993-1998 on the same watershed. I found significantly higher nitrate fluxes, and significantly lower fluxes for both forms of phosphorous, compared to the 1993-1998 sampling period. The relationships of all nutrient concentrations to streamflow was similar between sampling periods: nitrate concentrations decreased with streamflow, and phosphate and total phosphorous concentrations increased. Annual streamflow did not change compared to the previous sampling period, however streamflow was significantly higher during current summer months. Similar results were not found on the nearby Nooksack River, which receives water from the study stream. Changes in nutrient fluxes and streamflow on upper Kamm Creek may be associated with regional or local shifts in land management strategies. Linking specific land management changes with nutrient flux shifts is essential for planners trying to balance local agricultural and environmental interests, and deserves further investigation.