Updates to a soil moisture-based global liquefaction model

Abstract

The importance of soil saturation condition in relation to liquefaction occurrence emphasizes the necessity for a reliable tool to accurately monitor soil moisture content during seismic events. The Soil Moisture Active Passive (SMAP) satellite provides near-real time measurements of surface and root zone soil moisture globally. Common proxies used to assess soil saturation in liquefaction analysis, such as water table depth patterns, historical mean annual precipitation measurements, and topographic conditions, may not be as effective. To address this, this paper introduces the use of satellite-based soil moisture data to enhance the understanding of the relationship between saturation conditions and liquefaction events. Established geospatial explanatory variables, along with new SMAP-based soil moisture parameters, were employed to develop a recently proposed global liquefaction model called the Soil Moisture-based Global Liquefaction Model (SMGLM), which was compared to an existing global liquefaction model. However, limitation of SMGLM arising from the coarse spatial resolution of remotely sensed soil moisture data highlights the need for updated SMGLM using soil moisture data with finer resolution. With the continuous advancement of earth observing satellites, the findings of this study could serve as a foundation for developing fully satellite-based models that utilize high-resolution, near-real time soil moisture data to identify liquefied sites. Incorporating near-real time ground-truth-based saturation condition is a crucial step towards addressing potential overestimation or underestimation of liquefaction likelihood that may result from using proxies for soil saturation in existing models.