Modeling a Dynamically Changing Landscape: Using ArcView Spatial Analyst to Evaluate Impacts
Track: Ecology, Archaeology, and Conservation
Author(s): Paula Jacks, Angela Johnson
KEA uses GIS technology to analyze a variety of environmental data including archaeology, biology, geology, hydrology, and social impacts. This paper shows how KEA tackled the problem of trying to analyze impacts to an area that had a dynamically changing landscape. The setting: a coastal river mouth in an urban area; the project: three alternative alignments for bridge construction; the problem: calculating impacts from bridge construction based on the current conditions would not reflect landscape fluctuations that are evident from past photos and that are expected in future years. The vegetation communities within many riverine systems change nearly seasonally. Our project team was challenged with evaluating the "modern" historic fluctuations that the wetland vegetation communities within our dynamic project setting undergo. The solution: using GIS and Spatial Analyst, KEA was able to model an "average grid" representing a composite of the fluctuations the vegetation communities have experienced in the past 18 years. This allowed the impacts associated with each alternative to be calculated in a manner that better reflects the changing conditions at the site.
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