Interactions Between Tectonic Geomorphology and Prehistoric Settlements: A Case Study in the Upper Thai‑Malay Peninsula (Chumphon and Ranong Provinces)

Peerasak Klubket1*, Chawalit Khaokhiew2, Praon Silapanth2, and Santi Pailoplee1

The Upper Thai‑Malay Peninsula, specifically Chumphon and Ranong Provinces, functioned as a critical trans‑peninsular conduit linking the Andaman Sea with the Gulf of Thailand. This study investigates the geoarchaeological interplay between the Ranong Fault Zone and the spatial distribution of prehistoric to early historic settlements within the region. Utilising GIS‑based geomorphological modelling and aerial photography, this research analyses 115 archaeological sites (98 in Chumphon and 17 in Ranong) distributed across diverse environmental contexts. The findings indicate that tectonic activity associated with the Ranong Fault Zone fundamentally configured the region’s physical geography, producing a central mountain range intersected by transverse plains and riverine networks. Crucially, these tectonic movements generated optimal ecological and geomorphological conditions, including reliable hydrological systems, sheltered coastal plains, and navigable valley corridors. Rather than functioning as geographic barriers, these structurally controlled topographies served as natural conduits that facilitated trans‑peninsular mobility. By integrating Settlement Theory with the Dynamic Landscape Model, this research demonstrates that the active tectonic properties of the fault zone served as the primary determinants of settlement site selection. This fault‑induced landscape provided essential natural infrastructure and strategic geographic advantages, affirming that tectonic geomorphology played a fundamental role in shaping early human adaptation and spatial distribution in the region.