Assessing Seismic Hazard Potential Considering Topographic Amplification: Combined Analysis of Topographic Slopes, Land Use, and Landslides

Northeast India is severely exposed to geological hazards, especially earthquakes and landslides, due to its complex seismotectonic setting and geo-climatic conditions. The topographic features such as ridges, hillslopes, and valleys can influence ground shaking during seismic activity and accompanying hazards. Therefore, the present study assesses the seismic hazard potential for Meghalaya, India, taking topographic effects into account. Recommendations made in present Italian and European (Eurocode-8) seismic codes are adopted to identify the localities with potential for topographic effects. The seismic hazard map and topographic amplification-based classification map are then integrated, and a classified map based on a natural break classification scheme is produced. The relation with recent land use/cover change (LUCC) is also evaluated, particularly for changes in the built area. The study reveals that hazard potential (in g) varies from 0.5 to 0.95 g for Meghalaya, in which ~ 39% of landmass show moderate to very high class (> 0.70 g). High landslide density is also observed in these localities especially along the Dauki Fault. Compared with LUCC, a significant increase in built area between 2017 and 2021 is observed in high-potential zones for Meghalaya (70.91% in high and 87.24% in very high class), indicating the necessity of cautious and risk informed urban planning and development practices to mitigate the exposure to seismic hazard, landslides and associated risks. Findings will assist in planning resilient infrastructure and urban development.