Analysis of Slope Sensitivity to Landslides by a Transdisciplinary Approach in the Framework of Future Development: The Case of La Trinité in Martinique (French West Indies)

Abstract

Landslide hazard and risk assessment (LHA & LRA) in the French West Indies is a big challenge, particularly in Martinique, where several factors contribute to high slope sensitivity to landslides. This sensitivity is particularly due to volcanic ground, hurricane seasons, and growing pressure from urban development. Thus, to protect future goods and inhabitants and avoid increased slope sensitivity to landslide, it is necessary to analyze by different ways and complementary approaches the future planned areas. This research focuses on a site the City Council of 'La Trinité' wishes to develop. The goals consist of locating landslide-prone areas and providing some recommendations/indications for future projects. The site is characterized by a hilly topography alternating steep slopes, gentle slopes, and eroded areas and is located on a complex lithology (i.e., andesite, basalt, and weathered materials). By combining several approaches and techniques (geology, geomorphology, geophysics, and modeling), it is demonstrated that some areas are particularly susceptible to landslide, notably where colluviums are juxtaposed to highly weathered materials. The different documents produced, based on modeling and expert knowledge, combined with indications should allow the definition of new susceptibility classes, taking into account probable anthropic influence and development. Even if the temporal probability of the experimental documents is not taken into account, they help with refining knowledge of landslide-prone areas and different types of instability. The documents should be discussed with end users for future planning.

Probabilistic landslide susceptibility analysis in tropical mountainous terrain using the physically based r.slope.stability model

“…A DTM with a spatial resolution of 10 × 10 m was provided by the Instituto Geográfico Agustín Codazzi. A soil thickness map was built using interpolation, employing an empirical relationship between soil thickness and slope angle in the study area (Aristizábal, 2013;Catani et al, 2010;Thiery et al, 2019). The computed residual soil depth ranges from 1 to 2.8 m.…”

Airborne Electromagnetics to Improve Landslide Knowledge in Tropical Volcanic Environments

“…Phenomena can be shallow, deep, rotational, translational, or complex. The many landslides in the Caribbean are mainly due to the following reasons: (i) A complex lithology with heterogeneous volcanic materials that are sometimes poorly consolidated and superimposition of healthy materials on highly weathered materials [12][13][14][15][16]; (ii) Hurricane and tropical storms associated with intense end heavy rainfalls [1,11,16,17].…”

“…= 15 × 10 4 m 3 ) in 1991 [18], which required €7 million in work to rehabilitate the slope after the event, and (ii) the Morne Callebasse landslide (vol. = 2 × 10 5 m 3 ) in 2011, which destroyed more than 20 buildings and the road 'RD 48 , bringing 75 expulsions and more than €17.1 million in works [15,18]. Therefore, anticipating landslides and improving their prevention in this French overseas territory has become a major challenge [8,15].…”

“…= 2 × 10 5 m 3 ) in 2011, which destroyed more than 20 buildings and the road 'RD 48 , bringing 75 expulsions and more than €17.1 million in works [15,18]. Therefore, anticipating landslides and improving their prevention in this French overseas territory has become a major challenge [8,15]. The first step in achieving these actions consists of assessing hazards [19][20][21].…”

“…; [31,32]) remains mandatory. Recently, in the framework of future development [15], there has been demonstrated interest in AEM to delineate landslide-prone areas and to improve landslide hazard assessment. New information brought by AEM has allowed a landslide hazard map to be modified by combining a 3D geological model derived from a joint analysis of field observations and AEM results and a PBM.…”