Geomorphological Characteristics Based on Morphography, Morphometry, and Geomorphic Processes of the Silungkang Area, Sawahlunto City, West Sumatra

Geomorphology provides essential information on landscape evolution through the analysis of landforms, surface processes, and their controlling factors. This study was conducted in the Silungkang area and its surroundings, Sawahlunto City, West Sumatra, which lies within the Ombilin Basin, an intramontane basin interpreted as an oblique-rift to pull-apart basin associated with the Sumatra Fault System. The objective of this research is to identify and classify the geomorphology of the study area through morphographic, morphometric, and geomorphic-process analyses, and to delineate the landform units that compose it. The method integrates primary field observation with secondary interpretation of the National Digital Elevation Model (DEMNas), and the landform units were delineated using established genetic landform-classification schemes. The results show that the area is dominated by hills (about 70%), with elevations ranging from 185.49 to 873.29 m and slopes spanning flat (0–2%) to very steep (56–140%). Two main drainage patterns developed: subdendritic (62%) and dendritic (38%), while debris flow and debris slide are the observed mass movements. Based on the integration of these parameters, eleven landform units were identified, ranging from fluvial plains to denudational, karst, and intrusive hills. These units demonstrate that the landscape evolution of the study area is controlled by the combination of lithology, tectonic activity, and exogenic processes of weathering and erosion.