Flood Risk and Vulnerability Analysis Project - Atlantic Climate ...

Figure 3-5. Error Matrix and Accuracy Statistics
Figure 3-5 represents the error matrix (a) and accuracy statistics (b) for the accuracy
assessment of the land cover classification of community watersheds in Newfoundland,
Canada. Diagonal counts (in green) represent agreement between classified and ground truth
data.
Additional accuracy assessment metrics are presented in section B of Figure 3-5. The omission
(iii) column represents points that were identified as the row class in the ground-truth data, but
were classified as some other land cover class. The commission (iv) column represent points
that were classified as the row class, but identified as another class in the ground-truth data.
The upper and lower limit columns represent the 95% confidence intervals for each class.
Intervals represent the range of accuracy percents expected through the random selection of
another set of points. Out of 1000 randomly selected set of points, 950 sets will generate
accuracy percents within these values. Overall accuracy indicates that almost 9 out of 10
locations randomly checked by a user will be classified correctly. Forests and water have the
highest accuracy, while barren ground and developed classes have the lowest. Of the 60
accuracy assessment points falling on areas classified as developed, 51 were verified as
developed, 2 were non-forest vegetation, 1 was wetland and 6 were on barren land (85%
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