Uncertainties in assessing the extent and legal compliance status of riparian forests in the eastern Brazilian Amazon

•Landsat imagery systematically underestimates areas of riparian forest.•Deforestation was higher within riparian zones than outside them.•Under current legislation c. 5 M ha of riparian zones do not need to be restored.•New incentives beyond the existing legal framework are key to encourage restoration.•Fine-resolution images are vital for effective implementation of legal regulations.