Krzysztof Gaidzik

Landslide manual and automated inventories, and susceptibility mapping using LIDAR in the forested mountains of Guerrero, Mexico

ABSTRACT Landslides are a pervasive natural disaster, resulting in severe social, environmental and economic impacts worldwide. The tropical, mountainous landscape in South-West Mexico is predisposed to landslides because of frequent hurricanes and earthquakes. The main goal of this study is to compare landslide susceptibility maps in Guerrero derived using high-resolution LIDAR (light detection and ranging) data from both a manual landslide event inventory and an automated landslide inventorying algorithm. The paper also highlights the importance of applying LIDAR data in landslide inventorying and susceptibility mapping. We mapped landslides based on two approaches: (1) manual mapping using satellite images and (2) automatic identification of landslide morphology employing the Contour Connection Method (CCM). We produced a landslide susceptibility map by computing the probability of landslide occurrence from statistical relationships of inventoried landslides detected with LIDAR digital terrain models (DTMs) and derived landslide-causing factors using the logistic regression method. Our results suggest that the automated inventory derived through the CCM algorithm with LIDAR DTMs effectively minimizes the time-consuming and subjective manual inventorying process. The high overall prediction accuracy (up to 0.83) from logistic regression demonstrates the validity and applicability deriving reliable landslide susceptibility maps from an automated inventory; however, LIDAR data are required.

Relating the long-term and short-term vertical deformation across a transect of the forearc in the central Mexican subduction zone

Author(s): Ramirez-Herrera, MT; Gaidzik, K; Forman, S; Kostoglodov, V; Burgmann, R; Johnson, CW | Abstract:

La Pintada landslide—A complex double-staged extreme event, Guerrero, Mexico

Abstract Extreme storms commonly trigger landslides in regions of humid, warm tropical climate causing loss of life and economic devastation. The tropical mountainous areas of Guerrero in southwest Mexico are frequently hit by extreme hurricanes and cyclones and thus prone to landslides. On 16 September 2013, a huge landslide resulted in 71 fatalities and destroyed a large part of La Pintada Village. We applied remote sensing techniques using the LIDAR DEM and high-resolution images of the La Pintada area, a post-landslide field survey, geotechnical laboratory tests of colluvium material from the landslide, and a slope stability analysis. We also interviewed eyewitnesses accounts of the event. Our results suggest that the 2013 La Pintada landslide was a complex and two-stage event. An intense four-day-long rainfall event related to the landfall of Hurricane Manuel resulted in the oversaturation of soil, which was the main factor that caused the landslide. The effect of rainfall was amplified by the lack of high and dense vegetation on the 250-m-high slope. The lack of vegetation and slope-under-cutting likely contributed to the decreased slope stability. We suggest that increased intensity of extreme storms has contributed to increased landslides in this area. Furthermore, in tropical climate areas, where significant population lives in mostly developing countries, the combination of these phenomena makes them highly vulnerable to extreme storms and landslide hazards.

Tectonic Setting of the Poszukiwaczy Skarbów Cave and the Groby Cave (Kraków Gorge, Western Tatra Mts., Poland)

Abstract The study area is located in the Tatra Mts., the part of Western Carpathians. In the Poszukiwaczy Skarbów Cave and the Groby Cave a tectonics structures has been documented. The structural analysis were made. In both caves the following joints set have been identified from 4 maximum of statistic analysis: 157/85 (max.I), 143/63 (max.II), 58/63 (max.III), 304/70 (max.IV). Nevertheless joint set participation of individual caves development have been diverse. In the development of the Poszukiwaczy Skarbów Cave, the most important joint set were latitudinal which is conjugate with fractures of III. maximum. This crossing of joints sets contribute to development of the main chamber. Maximum III has been very important in the evolution of passages of the Groby Cave. Conjugated with joint of max. IV determined the conduit direction. Entrance chamber formed in this place because the overthrust disintegrated a rocks there. Abstract Jaskinia Poszukiwaczy Skarbów i Jaskinia Groby zlokalizowane są w Tatrach, w dolnej, zachodniej części Wąwozu Kraków. W jaskiniach wykonano pomiary orientacji struktur tektonicznych. Następnie wykonano analizę strukturalną, która pozwoliła wyznaczyć 4 główne zespoły spękań: 157/85 (max.I), 143/63 (max.II), 58/63 (max.III), 304/70 (max.IV). Udział poszczególnych zespołów spękań w obu jaskiniach był zróżnicowany. W Jaskini Poszukiwacz Skarbów najistotniejszy w rozwoju jaskini jest zespół spękań równoleżnikowych. Jego sprzężenie ze spękaniami III. maksimum uwarunkowało rozwój głównej komory. Spękania maksimum III są również istotne w rozwoju Jaskini Groby. Sprzężone z zespołem spękań max. IV determinowały kierunek korytarzy jaskini. Komora wstępna w Jaskini Groby założona jest na nasunięciu, które przyczyniło się do dezintegracji skał i ułatwiło rozwój sali.