Map showing susceptibility to rainfall-triggered landslides in the municipality of Ponce, Puerto Rico

Assessing locations susceptible to shallow landslide initiation during prolonged intense rainfall in the Lares, Utuado, and Naranjito municipalities of Puerto Rico

“…In a later post-Hurricane Maria, island-wide assessment using the frequency ratio method, Hughes and Schulz (2020a) found after accounting for the effects of soil moisture, there were strong correlations between landslides and slope, curvature, geologic terrane, mean annual precipitation, land cover, soil type, event soil moisture, proximity to roads, and proximity to fluvial channels for the Hurricane Maria event. Previous, more localized studies considered fewer geomorphic and geographic characteristics to classify landslide susceptibility using empirical and statistical methods (Larsen and Parks, 1998;Larsen et al, 2004). For example, Larsen and Parks (1998) classified landslide susceptibility of Comerío Municipality based on elevation, slope, aspect, and land use.…”

“…Likewise, this is valid for our quasi-3D slope stability analysis. Although much progress has been made in methods for assessing landslide susceptibility (e.g., Carrara et al, 1999;Chung and Fabbri, 2003;Lee et al, 2003;Godt et al, 2008b;Baum et al, 2014;Canli et al, 2018) as well as debris-flow inundation (George and Iverson, 2014;Reid et al, 2016;Aaron et al, 2017;Bessette-Kirton et al, 2019b), combining these two types of assessments into a single map for an area of hundreds of square kilometers remains challenging (Ellen et al, 1993;Benda et al, 2007;Fan et al, 2017;Hsu and Liu, 2019;Mergili et al, 2019). As noted previously, one of the challenges is estimating potential source-area extent and depth.…”

Assessing Locations Susceptible to Landslide Initiation During Prolonged Intense Rainfall in the Lares, Utuado, and Naranjito Municipios of Puerto Rico

“…In a later post-Hurricane Maria, island-wide assessment using the frequency ratio method, Hughes and Schulz (2020a) found after accounting for the effects of soil moisture, there were strong correlations between landslides and slope, curvature, geologic terrane, mean annual precipitation, land cover, soil type, event soil moisture, proximity to roads, and proximity to fluvial channels for the Hurricane Maria event. Previous, more localized studies considered fewer geomorphic and geographic characteristics to classify landslide susceptibility using empirical and statistical methods (Larsen and Parks, 1998;Larsen et al, 2004). For example, Larsen and Parks (1998) classified landslide susceptibility of Comerío Municipality based on elevation, slope, aspect, and land use.…”

“…Likewise, this is valid for our quasi-3D slope stability analysis. Although much progress has been made in methods for assessing landslide susceptibility (e.g., Carrara et al, 1999;Chung and Fabbri, 2003;Lee et al, 2003;Godt et al, 2008b;Baum et al, 2014;Canli et al, 2018) as well as debris-flow inundation (George and Iverson, 2014;Reid et al, 2016;Aaron et al, 2017;Bessette-Kirton et al, 2019b), combining these two types of assessments into a single map for an area of hundreds of square kilometers remains challenging (Ellen et al, 1993;Benda et al, 2007;Fan et al, 2017;Hsu and Liu, 2019;Mergili et al, 2019). As noted previously, one of the challenges is estimating potential source-area extent and depth.…”

Sediment Mobilization by Hurricane‐Driven Shallow Landsliding in a Wet Subtropical Watershed

“…One‐hour and daily rainfall thresholds for shallow landslide initiation in PR are in the 50–90 mm h −1 and 110–160 mm d −1 range, respectively (Larsen & Simon, 1993; Pando et al., 2005). Prominent landslide occurrence on the island has been associated with slope gradients ranging from 30° to 45° (Larsen & Parks, 1998; M. C. Larsen et al., 2004), lithologies with volcanic, volcaniclastic, hydrothermally altered, and intrusive origins (Monroe, 1979), and specific land cover classes such as cropland, pasture, and built‐up areas (Larsen & Torres‐Sánchez, 1998; Lepore et al., 2012). The influence of roads in slope instability has been crucial in some areas (Larsen & Parks, 1997), but has been ambiguous in others (Lepore et al., 2012).…”