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Identification of linear and threshold responses in streams along a gradient of urbanization in Anchorage, Alaska

Hydrobiologia

By:
,
DOI: 10.1023/A:1026211808745

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Abstract

We examined biotic and physiochemical responses in urbanized Anchorage, Alaska, to the percent of impervious area within stream basins, as determined by high-resolution IKONOS satellite imagery and aerial photography. Eighteen of the 86 variables examined, including riparian and instream habitat, macroinvertebrate communities, and water/sediment chemistry, were significantly correlated with percent impervious area. Variables related to channel condition, instream substrate, water chemistry, and residential and transportation right-of-way land uses were identified by principal components analysis as significant factors separating site groups. Detrended canonical correspondence analysis indicated that the macroinvertebrate communities responded to an urbanization gradient closely paralleling the percent of impervious area within the subbasin. A sliding regression analysis of variables significantly correlated with percent impervious area revealed 8 variables exhibiting threshold responses that correspond to a mean of 4.4-5.8% impervious area, much lower than mean values reported in other, similar investigations. As contributing factors to a subbasin's impervious area, storm drains and roads appeared to be important elements influencing the degradation of water quality with respect to the biota.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Identification of linear and threshold responses in streams along a gradient of urbanization in Anchorage, Alaska
Series title:
Hydrobiologia
DOI:
10.1023/A:1026211808745
Volume
501
Year Published:
2003
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Hydrobiologia
First page:
117
Last page:
131
Number of Pages:
15