High-Resolution Land Cover Mapping in the Colombian Andes: A 1:25,000 Scale Assessment of the Tolima Department

Regional environmental management and territorial planning require precise, high-resolution land cover data to establish accurate baselines. While previous regional assessments in the Tolima Department, Colombia, relied on coarser 1:100,000 scales, a critical knowledge gap remained regarding the availability of highly detailed spatial data for monitoring fragile Andean ecosystems. This study addresses this gap by developing a comprehensive 1:25,000 scale land cover map for the year 2021. The core methodological innovation lies in extending the CORINE Land Cover framework adapted for Colombia (CLC-C) to a highly detailed 6th hierarchical level, leveraging the three-meter spatial resolution of PlanetScope satellite imagery. This approach significantly reduces the Minimum Mapping Unit (MMU) to 1.56 hectares (0.75 hectares for artificialized areas), which represents a major benefit over coarser scales. By shrinking the MMU, this work successfully delineates highly fragmented landscapes, transitional vegetation, and strategic Andean micro-ecosystems—such as peatlands, glaciers, and frailejonales—that are typically generalized or lost at coarser scales. The visual interpretation of pictorial–morphological features was refined through extensive fieldwork across 47 municipalities to resolve classification ambiguities. The final map exhibits exceptional cartographic quality, achieving a global reliability between 97.8% and 98.3% and a sampling error below 0.80% based on stratified random sampling. Results indicate that "Forests and semi-natural areas" are the dominant land cover category, spanning 60.10% (1,451,253.14 ha) of the department, while "Agricultural territories" occupy 37.88% (914,670.75 ha). By providing unprecedented spatial detail, this high-resolution baseline enhances the technical capacity for water resource management and conservation policies in the Colombian Andes.