Assessing long-term land cover changes in watershed by spatiotemporal fusion of classifications based on probability propagation: The case of Dniester river basin

Abstract

Broad-scale land cover classifications created by using satellite imagery are recognized as important and necessary input to land cover mapping. Evaluation of land cover changes is essential for sustainable watershed management. In this research, a framework for quantitative assessment of long-term land cover changes over large areas is developed. A key feature of the framework is a spatiotemporal fusion of classifications. Herein, a method to resolve the inconsistency of land cover classes at overlapped multi-segment and multi-temporal classifications by considering their probability propagation is proposed. The framework was applied in assessing long-term land cover changes in the Dniester river basin. Two land cover maps, for 2002 and 2018, were obtained with overall accuracy of 81.42% and 81.30%, respectively. The subsequent analysis and quantitative assessment of sixteen-year land cover changes by T. Saaty's analytic hierarchy procedure resulted in a map of the significance of these long-term land cover changes for the Dniester river basin. The major part of the basin (81.6%) exhibits no changes. Land cover changes maintaining favorable conditions for watershed appear over 10.5% of the area, while harmful changes occur over 7.9% of the territory.