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UW001

Effects of land cover, topography, and built structure on seasonal water quality at multiple spatial scales in Clark County, WA and the metropolitan area of Portland, OR

  • Creator(s): Heejun Chang
  • PI(s): Heejun Chang
  • Originator(s): Heejun Chang
  • Other researcher(s):
  • Dates of data preparation: Jan 7 1998 - Aug 30 2010
  • Data collection status: Study collection is completed and no new collection is planned
  • Data access: Online
  • Last update: Dec 18 2012 (Version 2)
<Citation>     <Acknowledgement>     <Disclaimer>    
Chang, H. 2012. Effects of land cover, topography, and built structure on seasonal water quality at multiple spatial scales in Clark County, WA and the metropolitan area of Portland, OR. Portland-Vancouver Urban Long-Term Research Area. Forest Science Data Bank, Corvallis, OR. [Database]. Available: http://andlter.forestry.oregonstate.edu/data/abstract.aspx?dbcode=UW001. Accessed 2024-06-15.
Data sets were provided by the Forest Science Data Bank, a partnership between the Department of Forest Science, Oregon State University, and the U.S. Forest Service Pacific Northwest Research Station, Corvallis, Oregon. Significant funding for these data was provided by the National Science Foundation Long-Term Ecological Research program (DEB-02-18088).
While substantial efforts are made to ensure the accuracy of data and documentation, complete accuracy of data sets cannot be guaranteed. All data are made available 'as is'. The Andrews LTER shall not be liable for damages resulting from any use or misinterpretation of data sets.
ABSTRACT:
The relationship among land cover, topography, built structure and stream water quality in the Portland Metro region of Oregon and Clark County, Washington areas, USA, is analyzed using ordinary least squares (OLS) and geographically weighted (GWR) multiple regression models. Two scales of analysis, a sectional watershed and a buffer, offered a local and a global investigation of the sources of stream pollutants. Model accuracy, measured by R2 values, fluctuated according to the scale, season, and regression method used. While most wet season water quality parameters are associated with urban land covers, most dry season water quality parameters are related topographic features such as elevation and slope. GWR models, which take into consideration local relations of spatial autocorrelation, had stronger results than OLS regression models. In the multiple regression models, sectioned watershed results were consistently better than the sectioned buffer results, except for dry season pH and stream temperature parameters. This suggests that while riparian land cover does have an effect on water chemistry and quality, a wider contributing area needs to be included in order to account for distant sources of pollutants.

Study Description Download Study Location Information: (CSV)
Ecological Metadata Language: (EML)
ENTITY TITLES:
1Monthly stream water chemistry data collected by the Portland Bureau of Environmental Services (Jan 7 1998 - Aug 30 2010)METADATADATA
Water chemistry parameters in Portland Metro area
2Methods of collection for monthly stream water chemistry data collected by the Portland Bureau of Environmental Services (Jan 7 1998 - Aug 30 2010)METADATADATA
Methods used to collect water chemistry parameters in Portland Metro area

RELATED MATERIALS:
 Portland-Vancouver ULTRA - The Portland-Vancouver Urban Long-Term Research Area Webpage

RELATED DATABASES:
 Adult Stewardship in 25 Natural Areas in the Portland-Vancouver Metropolitan Area from September 2011 through June 2012 (UE001)
 Interviews with Portland-Vancouver region government officials about water resource policies collected in 2011 (UG001)
 Analysis of riparian vegetation loss in Hillsboro, Oregon City and Portland, Oregon from 1990-2008 (UI001)