Riparian areas contain structurally diverse habitats that are challenging to monitor routinely and accurately over broad areas.
As the structural variability within riparian areas is often indiscernible using moderate-scale satellite imagery, new mapping
techniques are needed. We used high spatial resolution satellite imagery from the QuickBird satellite to map harvested and
intact forests in coastal British Columbia, Canada. We distinguished forest structural classes used in riparian restoration
planning, each with different restoration costs. To assess the accuracy of high spatial resolution imagery relative to coarser
imagery, we coarsened the pixel resolution of the image, repeated the classifications, and compared results. Accuracy assessments
produced individual class accuracies ranging from 70 to 90% for most classes; whilst accuracies obtained using coarser scale
imagery were lower. We also examined the implications of map error on riparian restoration budgets derived from our classified
maps. To do so, we modified the confusion matrix to create a cost error matrix quantifying costs associated with misclassification.
High spatial resolution satellite imagery can be useful for riparian mapping; however, errors in restoration budgets attributable
to misclassification error can be significant, even when using highly accurate maps. As the spatial resolution of imagery
increases, it will be used more routinely in ecosystem ecology. Thus, our ability to evaluate map accuracy in practical, meaningful
ways must develop further. The cost error matrix is one method that can be adapted for conservation and planning decisions
in many ecosystems.
Keywords Riparian conservation and restoration - object-based image classification - high spatial resolution satellite imagery - accuracy assessment - map accuracy - QuickBird - confusion matrix - cost error matrix - coastal streams - restoration