Stress Testing the Resilience of Regional Spatial Structure to Hydrometeorological Disaster Disruptions: Empirical Evidence from West Sumatra

Abstract

Hydrometeorological disasters frequently disrupt transportation networks and threaten the functioning of regional spatial systems, particularly in geographically constrained regions. However, previous studies have primarily evaluated resilience from the perspective of transportation network performance, with limited attention to how transportation disruptions affect the continuity of hierarchical interactions among activity centers. This study assessed the resilience of the regional spatial structure in West Sumatra, Indonesia, by examining how hydrometeorological disaster disruptions influence regional connectivity under progressively increasing transportation network stress. An ex-post GIS-based stress-testing framework was developed using three disruption scenarios (conservative, moderate, and worst-case) to evaluate primary corridor functionality and alternative accessibility between the National Activity Center (NAC) and Regional Activity Centers (RACs). Changes in travel distance, travel time, and connectivity were analyzed to assess the continuity of hierarchical regional interactions. The results indicated that maintaining physical connectivity alone does not guarantee regional spatial structure resilience. Under moderate disruption, all origin-destination pairs remained connected; however, substantial travel-time increases revealed considerable deterioration in functional accessibility. Under the worst-case scenario, failure of critical primary corridors caused widespread network fragmentation and functional collapse of the regional interaction system. These findings demonstrate that regional spatial structure resilience depends not only on transportation connectivity but also on the ability of the transportation system to sustain hierarchical interactions among activity centers during disaster conditions. The proposed framework bridges transportation network analysis and regional spatial planning and provides a transferable approach for evaluating disaster resilience in mountainous and hazard-prone regions characterized by limited transportation redundancy.