Geoscience Reference
In-Depth Information
13
CHAPTER
Mapping Spatial Accuracy and Estimating
Landscape Indicators from Thematic Land-Cover
Maps Using Fuzzy Set Theory
Liem T. Tran, S. Taylor Jarnagin, C. Gregory Knight, and Latha Baskaran
CONTENTS
13.1 Introduction...........................................................................................................................173
13.2 Methods ................................................................................................................................174
13.2.1 Multilevel Agreement ...............................................................................................176
13.2.2 Spatial Accuracy Map ..............................................................................................177
13.2.3 Degrees of Fuzzy Membership ................................................................................177
13.2.4 Fuzzy Membership Rules.........................................................................................178
13.2.5 Fuzzy Land-Cover Maps ..........................................................................................180
13.2.6 Deriving Landscape Indicators.................................................................................180
13.3 Results and Discussion.........................................................................................................180
13.4 Conclusions...........................................................................................................................186
13.5 Summary...............................................................................................................................186
Acknowledgments ..........................................................................................................................187
References ......................................................................................................................................187
13.1 INTRODUCTION
The accuracy of thematic map products is not spatially homogenous, but rather variable across
most landscapes. Properly analyzing and representing the spatial distribution (pattern) of thematic
map accuracy would provide valuable user information for assessing appropriate applications for
land-cover (LC) maps and other derived products (i.e., landscape metrics). However, current thematic
map accuracy measures, including the confusion or error matrix (Story and Congalton, 1986) and
Kappa coefficient of agreement (Congalton and Green, 1999), are inadequate for analyzing the spatial
variation of thematic map accuracy. They are not able to answer several important scientific and
application-oriented questions related to thematic map accuracy. For example, are errors distributed
randomly across space? Do different cover types have the same spatial accuracy pattern? How do
spatial accuracy patterns affect products derived from thematic maps? Within this context, methods
for displaying and analyzing the spatial accuracy of thematic maps and bringing the spatial accuracy
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