Evidence for deviations from uniform changes in a Portuguese watershed illustrated by CORINE maps: An Intensity Analysis approach

• Published in: Ecological indicators 2016-07, Vol.66, p.382-390
• Main Authors: Teixeira, Zara, Marques, João C., Pontius, Robert Gilmore
• Format: Article
• Language: English
• Subjects: Accuracy; Coastal system; coasts; Hydrologic processes; hydrology; Indicator; Land cover; light intensity; Transitions; Watershed; watersheds
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2016.01.018

•CORINE maps are used as indicators of landscape change.•Errors on 2.0% of the spatial extent could account for non-uniform changes.•Maps appear to show some changes that are inconsistent with historical processes.•Map error might account for apparent gains to industrial and heterogeneous.•Map error might account for apparent transitions to urban, industrial and water. We apply a method to evaluate the strength of the evidence for deviations from uniform land change in a coastal area, in the context of Intensity Analysis. The errors in the CORINE maps at 1990 and 2006 can influence the apparent change, but the errors are unknown because error assessment of the 1990 map has never been released, while the error of the 2006 map has been checked for only some countries. The 1990 and the 2006 maps of a coastal watershed in Portugal served as the data to compute the intensities of changes among eight categories. We evaluate the sizes and types of errors that could explain deviations from uniform intensities. Errors in 2.0% of the 2006 map can explain all apparent deviations from uniform gains. Errors in 1.5% of the 1990 map can explain all apparent deviations from uniform losses. Errors in less than 0.7% of the 1990 map can explain all apparent deviations from uniform transitions to each gaining category. We analyse the strength of the evidence for deviations from uniform intensities in light of historical processes of change. Historical processes can explain some transitions that the data show, while the hypothesised errors in the data are the explanation for other transitions that are not consistent with known processes. Inconsistent transitions are an indication of the misclassification errors that could propagate to other land cover change applications, as in the assessment of hydrological processes.