Noida, located within India's National Capital Region and near the tectonically active Himalayan region, is highly susceptible to seismic activity. Past moderate to high-intensity seismic events emphasize the need for detailed subsurface characterization to enhance seismic hazard assessments. This study investigates seismic site effects in Noida using microtremor measurements and the Nakamura technique to develop spatial distribution maps for seismic amplification, fundamental frequency, and seismic vulnerability index. A total of 129 microtremor data points were collected, with 54 meeting the SESAME criteria for reliable Horizontal-to-Vertical Spectral Ratio (HVSR) analysis. The analysis reveals that the predominant frequency at most sites falls within the range of 0.63-1.10 Hz, indicating the widespread presence of thick, soft sediments in the area. To avoid structural damages caused by the resonance of soil and structure and a table is prepared to showcase the approximate building frequency of various storey in order to avoid soil-building resonance phenomenon. The maximum amplification (A(0)) observed ranges from 4.53 to 5.17 at a few sites, whereas the majority of the study area experiences low to moderate amplification. The calculated seismic vulnerability index (K-g) for the 54 studied locations ranges from 2.27 to 23.60, with higher values found in regions with soft alluvial deposits, identifying them as fragile zones likely to suffer infrastructure damage during an earthquake. Lower K-g values correspond to areas with stiffer substrates. This study provides a preliminary assessment for urban planning and highlights the need for further research into the socio-economic and structural seismic vulnerabilities of the Noida region.
