Exploring Spatio-temporal change in global land cover using categorical intensity analysis

Global land degradation and urbanization are rapidly progressing during the 21st century. Herein, we assessed Spatio-temporal changes in global land cover using categorical intensity analyses from 1992 to 2018 to evaluate global land degradation and urbanization. Specifically, we evaluated the decrease, increase, and expansion processes and observed temporal differences. These evaluations were performed on a global scale across continents and climates at a category level for six-term intervals. Intensity analysis is a means of characterizing differences between sets at multiple time points using mathematics. In this study, inputs were gridded land cover from 1992, 1997, 2002, 2007, 2012, 2015, and 2018 and for six land categories: “Cropland,” “Forest,” “Shrubland,” “Built,” “Bare areas,” and “Other” The analysis of change for the 26 years shows that the cropland area increased globally by 786,656 km2 between 1992 and 2018. The areas occupied by forests continuously decreased by 936,960 km2, especially in South America which experienced the highest decline. Urban areas increased by 436,084 km2, with the highest increase observed in temperate regions. This paper concludes that for the last 26 years, land has been converted and degraded attributable to urbanization in temperate regions. Additionally, in South America and tropical regions, the expansion of cropland is the biggest contributor to the decline in “Forests” and “Shrubland”. The largest component of change was observed for the “Built” category. while, “Forest” and “Cropland” experienced significant losses and gains in the first, second, and third intervals.