Temporal vegetation cover dynamics in Northwestern Ethiopia: Status and trends

Abstract

The vegetation cover change of northwestern Ethiopia’s high forests has not been investigated and no information is available on temporal changes in particular with vegetation cover dynamics. Thus, our study explores the trend of vegetation cover changes of the study area in the last 42 years. Landsat satellite images of the years 1973, 1987, 2001 and 2014 were acquired from the Earth Explorer website. Preprocessing of images, image classification, accuracy assessment, post classification image processing and change detection were carried out. The overall classification accuracy and Kappa coefficient were found to be above 85% and 0.8, respectively, for all study years. Four land use/cover classes were identified for the supervised classification. In 1973, the largest proportion (40%) was covered by primary forest, followed by agriculture (39%), grassland (12%) and secondary forest (9%). In 2014, agriculture covered the largest proportion (45%), followed by secondary forest (29%), grassland (17%) and primary forest (9%). The rate of conversion of the primary forest cover to other land use types was found to be above the national average conversion rate; which is highly alarming. Thus, introducing appropriate management options is urgently needed to halt those conversions.