skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.


Title: Learnings from rapid response efforts to remotely detect landslides triggered by the August 2021 Nippes earthquake and Tropical Storm Grace in Haiti
Abstract On August 14, 2021, aMw7.2 earthquake struck the Tiburon Peninsula of western Haiti triggering thousands of landslides. Three days after the earthquake on August 17, 2021, Tropical Storm Grace crossed shallow waters offshore of southern Haiti triggering more landslides worsening the situation. In the aftermath of these events, several organizations with disaster response capabilities or programs activated to provide information on the location of landslides to first responders on the ground. Utilizing remote sensing to support rapid response, one organization manually mapped initiation point of landslides and three automatically detected landslides. The 2021 Haiti event also provided a unique opportunity to test different automated landslide detection methods that utilized both SAR and optical data in a rapid response scenario where rapid situational awareness was critical. As the methods used are highly replicable, the main goal of this study is to summarize the landslide rapid response products released by the organizations, detection methods, quantify accuracy and provide guidelines on how some of the shortcomings encountered in this effort might be addressed in the future. To support this validation, a manually mapped polygon-based landslide inventory covering the entire affected area was created and is also released through this effort.  more » « less
Award ID(s):
2023112
PAR ID:
10543654
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Springer Link
Date Published:
Journal Name:
Natural Hazards
Volume:
118
Issue:
3
ISSN:
0921-030X
Page Range / eLocation ID:
2337 to 2375
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Remote reconnaissance missions are promising solutions for the assessment of earthquake-induced structural damage and cascading geological hazards. Space-borne remote sensing can complement in-field missions when safety and accessibility concerns limit post-earthquake operations on the ground. However, the implementation of remote sensing techniques in post-disaster missions is limited by the lack of methods that combine different techniques and integrate them with field survey data. This paper presents a new approach for rapid post-earthquake building damage assessment and landslide mapping, based on Synthetic Aperture Radar (SAR) data. The proposed texture-based building damage classification approach exploits very high resolution post-earthquake SAR data integrated with building survey data. For landslide mapping, a backscatter intensity-based landslide detection approach, which also includes the separation between landslides and flooded areas, is combined with optical-based manual inventories. The approach was implemented during the joint Structural Extreme Event Reconnaissance, GeoHazards International and Earthquake Engineering Field Investigation Team mission that followed the 2021 Haiti Earthquake and Tropical Cyclone Grace. 
    more » « less
  2. Abstract. Rapid detection of landslides is critical for emergency response, disaster mitigation, and improving our understanding of landslide dynamics. Satellite-based synthetic aperture radar (SAR) can be used to detect landslides, often within days of a triggering event, because it penetrates clouds, operates day and night, and is regularly acquired worldwide. Here we present a SAR backscatter change approach in the cloud-based Google Earth Engine (GEE) that uses multi-temporal stacks of freely available data from the Copernicus Sentinel-1 satellites to generate landslide density heatmaps for rapid detection. We test our GEE-based approach on multiple recent rainfall- and earthquake-triggered landslide events. Our ability to detect surface change from landslides generally improves with the total number of SAR images acquired before and after a landslide event, by combining data from both ascending and descending satellite acquisition geometries and applying topographic masks to remove flat areas unlikely to experience landslides. Importantly, our GEE approach does not require downloading a large volume of data to a local system or specialized processing software, which allows the broader hazard and landslide community to utilize and advance these state-of-the-art remote sensing data for improved situational awareness of landslide hazards. 
    more » « less
  3. Landslides are a significant hazard and dominant feature throughout the landscape of the Pacific Northwest. However, the hazard and risk posed by coseismic landslides triggered by great Cascadia Subduction Zone (CSZ) earthquakes is highly uncertain due to a lack of local and global data. Despite a wealth of other geologic evidence for past earthquakes on the Cascadia Subduction Zone, no landslides have been definitively linked to such earthquakes, even in areas otherwise highly susceptible to failure. While shallow landslides may not leave a lasting topographical signature in the landscape, there are thousands of deep-seated landslides in Cascadia, and these deposits often persist for hundreds of years and multiple earthquake cycles. Synthesizing newly developed inventories of dated large deep-seated landslides in the Oregon Coast Range, we use statistical methods to estimate the proportion of these types of landslides that could have been triggered during past great Cascadia Subduction Zone earthquakes. Statistical analysis of high-precision dendrochronology ages of landslide-dammed lakes and surface roughness-dated bedrock landslides reveal Cascadia Subduction Zone earthquakes may have triggered 0–15 % of large deep-seated landslides in the Oregon Coast Range over multiple earthquake cycles. Our results refine estimates from previous studies and further suggest that coseismic triggering accounts for a small fraction of the total deep-seated bedrock landslides mapped in coastal Cascadia. However, if the real rate of coseismic landslide triggering during CSZ earthquakes is near our estimated upper bound for the 1700 CSZ earthquake, we estimate up to 2400 coseismic large deep-seated landslides could occur in the Oregon Coast Range in a single earthquake. These findings suggest Cascadia is consistent with global observations from other subduction zones and that coseismic landslides may still represent a serious geohazard in the region. 
    more » « less
  4. Eric Calais; Silvia Chacón-Barrantes; Roby Douilly; O’Leary Gonzalez; Xyoli Pérez-Campos; Richard Robertson, Elizabeth Vanacore (Ed.)
    The Mw 7.2 Nippes, Haiti, earthquake occurred on 14 August 2021 in Haiti’s southwest peninsula and in the midst of significant social, economic, and political crises. A hybrid reconnaissance mission (i.e., combined remote and field investigation) was coordinated to document damage to the built environment after the event. This article evaluates two ground‐motion records available in Haiti in the context of the geology of the region and known areas with significant damage, such as Les Cayes. We also present a new map of time‐averaged shear‐wave velocity values to 30 m depth (⁠VS30 ⁠) for Les Cayes and Port‐au‐Prince based on the geostatistical approach of kriging and accounting for region‐specific geology proxies and field measurements of VS30 ⁠. Case studies of ground failure observations, including landslides and liquefaction triggering, are described as well as the intersection of social and engineering observations. Maps depicting this important intersection are provided to facilitate the assessment of how natural hazards and social conflicts have influenced the vulnerability of Haiti’s population to earthquakes. 
    more » « less
  5. The data were collected in the Helambu region of central Nepal as part of the "Nepal-FRES" (Frontier Research in Earth Sciences) project to document the impacts of the 2021 Melamchi Flood, aiming to understand its cascading nature, the legacy of the 2015 Gorkha earthquake, and fluvial adjustment to such an extreme sediment transporting event. Polygon KML files of landslides, active river channels, and river terraces were mapped using 50 cm-resolution pre- and post-event Pléiades stereo satellite imagery. This data package comprises:  Melamchi Khola Catchment (study area)  Landslides before the 2015 Gorkha earthquake, between 2015 and 2020, between Nov 2020 and Oct 2021 (Melamchi Flood), and between Oct 2021 and Dec 2023  Obscured areas in which landslide mapping is incomplete due to the existence of clouds and shadow  River channel of Melamchi Khola in Nov 2020 and Oct 2021 (w/ the thalweg line in Oct 2021)  River terraces in Oct 2021  Forested areas in Nov 2020 and Dec 2023 
    more » « less