Date of Award

2012

Document Type

Honors Thesis (Open Access)

Department

Colby College. Environmental Studies Program

Advisor(s)

Philip J. Nyhus

Second Advisor

Russell Cole

Third Advisor

Whitney King

Abstract

Shoreline buffers are essential to maintaining lake water quality and there are numerous methods for their assessment. There is uncertainty in the benefits and drawbacks of different shoreline buffer assessment methods. In this study I explore three methods of remotely assessing shoreline buffers in the Belgrade Lakes Region of Maine: household surveys, geotagged shoreline photos, and satellite imagery. By comparing these three methods I will evaluate their accuracy and applicable scale when used to assess the presence and quality of shoreline buffers.

I used both parametric and non-parametric analysis to (1) evaluate the relative accuracy of 154 household surveys in identifying buffer presence or quality, (2) compare experts in their evaluation of 98 geotagged photos of buffers, (3) assess the accuracy of approximately 450 million square meters of classified Geoeye-1 imagery, and (4) compare the three buffer assessment methods across lakes and demographic factors. Relative to an expert assessment, shoreline residents similarly identified the presence of buffers but significantly differently estimated their extent and quality. Experts differed in how they assessed the extent and quality of buffers. Classified satellite imagery did not significantly predict an expert assessment of buffer presence or quality. While not significant, inter-lake comparison found that North Pond residents assess buffers slightly differently than Great Pond or East Pond residents.

These findings suggest that household surveys and geotagged shoreline photos are valuable tools for evaluating shoreline buffers. Satellite imagery is informative at a lake or watershed scale, but has limitations at a lot scale. Continued lake stewardship education efforts are important and should be supplemented, not replaced, by remote assessment methods.

Keywords

Satellite, Survey, GIS, Remote Sensing, Geoeye, Belgrade Lakes

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