MODELING ESTIMATED VS30BASED ON TOPOGRAPHY AND GEOMORPHOLOGY FOR PADANG, INDONESIA

Modeling estimated shear-wave velocity over the top 30 m (Vs30) for Padang city, based on three proxies, namely topography slope, elevation, and geomorphology unit is reported in this paper. First, seven regression analyses were conducted to provide Vs30 models. Vs30 from direct measurement by the MASW (Multi-channel Analysis of Surface Waves) surveys was used as a criterion variable. Topography slope and elevation from SRTM 30 (Shuttle Radar Topography Missile) data, and geomorphology unit were used as explanatory variables. Second, the Vs30 models were used in spatial analyses using Map Algebra. Based on the statistics and the result of Vs30 estimation map, the best model is Model 1 employing all proxies. We expect that estimated Vs30 presented here will support the seismic risk mitigation effort in Padang city.