← Back to Sessions

Basin Identification Using the Continuous Wavelet Transform on Digital Elevation Models for Seismic Hazard Analysis

Description: 

Accurately identifying sedimentary basins and modeling their associated amplification effects are critical for seismic hazard analysis, especially in regions like California, where seismic hazards are significantly influenced by sedimentary basins. Traditional methods for basin identification depend on manual efforts, which are time-consuming, labor-intensive, and prone to uncertainties from subjective judgment. Current ground motion models use depth parameters such as Z_1.0​and Z_2.5​ that derived from tomographic velocity models to model basin effects. This approach introduces additional uncertainties that vary spatially across the velocity models as velocity models have variable accuracy and are only available in a few regions worldwide.In this study, we present an automated method for identifying sedimentary basins using 90 m Digital Elevation Models (DEMs). Topographic features often reveal underlying geological structures, with basins typically appearing as low, flat terrains resulting from sediment deposition in natural depressions. By applying the Continuous Wavelet Transform (CWT), we decompose the topography into different length scales. Sedimentary basins exhibit distinct characteristics: minimal coefficients at small scales due to the lack of local roughness and negative coefficients at scales corresponding to basin extents. By identifying these features automatically, our approach detects basins in the western U.S., producing results consistent with traditional manual methods while also identifying additional basins that manual approaches may have overlooked. Furthermore, the wavelet function at ground motion station locations, represented as wavelet coefficients across length scales, is utilized to develop site models for the NGA-West 3 project. This method offers a high-resolution and accurate identification of basins and their characteristics and can be used to predict basin amplification effects. This method can be easily extended to other regions globally, leveraging the widespread availability of high-quality DEMs.

Session: Challenges and Opportunities in Constraining Ground-motion Models from Physics-based Ground-motion Simulations [Poster]

Type: Poster

Date: 4/17/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Shiying

Student Presenter: No

Invited Presentation: 

Poster Number: 46

Authors