Abstract:
ABSTRACT
MAPPING VEGETATION IN CALIFORNIA’S CASCADE FOOTHILLS:
BIG CHICO CREEK, CHICO, CALIFORNIA
by
Erec DeVost
Master of Arts in Geography
California State University, Chico
Summer 2009
The Big Chico Creek Vegetation Mapping Project (hereafter the Project) is a
study for creating alliance level vegetation datasets from aerial imagery with the
support of geographic information system (GIS) ancillary data. The project area east of
Chico, California, is a transition zone from grasslands of the valley, to the oak
woodland foothills, culminating in pine dominated forests in the higher elevations. The
project was developed because current regional vegetation maps (e.g., USGS GAP
maps) lack either the grain or extent needed to conduct landscape level biological
research and support natural resource management. Color high-resolution digital aerial
photos were interpreted using a GIS to develop a photo interpretation key, then
classified according to the Manual of California Vegetation classification system. These
methods and classification system allow the project to be incorporated into existing
natural resources
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datasets. Currently the Big Chico Creek vegetation database contains 872 vegetation
polygons representing 23 different alliance types found within the 4,507 hectare study
area. Methods used to conduct a statistical error assessment of the final dataset
introduced the observer effect into the analysis. For this reason, the accuracy of this
dataset can not be statistically proven.
