Landslide detection and susceptibility mapping are crucial in risk management and urban planning. Constant advance in digital elevation models accuracy and availability, the prospect of automatic landslide detection, together with variable processing techniques, stress the need to assess the effect of differences in input data on the landslide susceptibility maps accuracy. The main goal of this study is to evaluate the influence of variations in input data on landslide susceptibility mapping using a logistic regression approach. We produced 32 models that differ in (1) type of landslide inventory (manual or automatic), (2) spatial resolution of the topographic input data, (3) number of landslide-causing factors, and (4) sampling technique. We showed that models based on automatic landslide inventory present comparable overall prediction accuracy as those produced using manually detected features. We also demonstrated that finer resolution of topographic data leads to more accurate and precise susceptibility models. The impact of the number of landslide-causing factors used for calculations appears to be important for lower resolution data. On the other hand, even the lower number of causative agents results in highly accurate susceptibility maps for the high-resolution topographic data. Our results also suggest that sampling from landslide masses is generally more befitting than sampling from the landslide mass center. We conclude that most of the produced landslide susceptibility models, even though variable, present reasonable overall prediction accuracy, suggesting that the most congruous input data and techniques need to be chosen depending on the data quality and purpose of the study.

Tectonically active areas, such as forearc regions, commonly show contrasting relief, differential tectonic uplift, variations in erosion rates, in river incision, and in channel gradient produced by ongoing tectonic deformation. Thus, information on the tectonic activity of a defined area could be derived via landscape analysis. This study uses topography and geomorphic indices to extract signals of ongoing tectonic deformation along the Mexican subduction forearc within the Guerrero sector. For this purpose, we use field data, topographical data, knickpoints, the ratio of volume to area (RVA), the stream-length gradient index (SL), and the normalized channel steepness index (ksn).The results of the applied landscape analysis reveal considerable variations in relief, topography and geomorphic indices values along the Guerrero sector of the Mexican subduction zone. We argue that the reported differences are indicative of tectonic deformation and of variations in relative tectonic uplift along the studied forearc. A significant drop from central and eastern parts of the study area towards the west in values of RVA (from ∼500 to ∼300), SL (from ∼500 to ca. 400), maximum SL (from ∼1500–2500 to ∼1000) and ksn (from ∼150 to ∼100) denotes a decrease in relative tectonic uplift in the same direction. We suggest that applied geomorphic indices values and forearc topography are independent of climate and lithology. Actual mechanisms responsible for the observed variations and inferred changes in relative forearc tectonic uplift call for further studies that explain the physical processes that control the forearc along strike uplift variations and that determine the rates of uplift. The proposed methodology and results obtained through this study could prove useful to scientists who study the geomorphology of forearc regions and active subduction zones

Geophysical and geological data from the eastern sector of the Central European Variscan belt are presented and reviewed in the regional tectonic context. Matched filtering of isostatic gravity, guided by results of spectral analysis, along with other derivatives of gravity and magnetic fields reveal a dominant WNW–ESE-trending pre-Permian structural grain in the external zones of the Variscan belt in Poland. This trend is confirmed by regional distribution of dips in Carboniferous and Devonian strata that were penetrated by boreholes beneath Permian-Mesozoic sediments. Based on these data, two alternative concepts explaining the connection of the Variscan belt and its NE foreland, those of strike-slip tectonics versus oroclinal bending, are discussed. The WNW–ESE structural trend in the Variscan foreland is parallel to a set of major strike-slip fault zones in the area, including those of Upper Elbe, Intra-Sudetic, Odra, Dolsk and Kraków-Lubliniec. These faults are considered to convey a significant dextral displacement between Laurussia and Gondwana. The revised position of the Variscan deformation front shows a similar, uninterrupted, generally WNW–ESE trend, up to the SE border of Poland, which indicates an initial continuation of the Variscan belt into the area of the present-day Western Carpathians. The geometry of the Variscan deformation front along with the pattern of the Variscan structural grain are inconsistent with the idea of an oroclinal loop affecting the external, non-metamorphic Variscan belt. However, the data presented do not entirely rule out an oroclinal loop within the Variscan internides. The still possible options are (1) a semi-oroclinal model postulating ~ 90° bending of the Variscan tectonostratigraphic zones into parallelism with the WNW–ESE strike-slip faults or (2) an orocline limited only to the belt linking the Wolsztyn High and Moravo-Silesian non- to weakly-metamorphic fold-and-thrust belt. Regardless of the kinematic model preferred, our data indicate that structural evolution of the Polish Variscides was concluded with the end-Carboniferous NNE–SSW shortening that resulted in the present-day extent of the Variscan deformation front.

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.

The Colca Canyon (Central Andes, Southern Peru), about 100 km long and 1–3 km deep, forms a magnificent cross section of the Earth’s crust giving insight into mutual relations between lithostratigraphical units, and allowing relatively easy interpretation of the fascinating geological history written in the rocky beds and relief. Current activity of tectonic processes related to the subduction of the Nazca plate beneath the South American Plate exposed the geological heritage within study area. Well-developed tectonic structures present high scientific values. The volcanic landforms in the Valley of the Volcanoes and around the Colca Canyon include lava flows, scoria cones and small lava domes. They represent natural phenomena which gained recognition among tourists, scientists and local people. Studies performed by the Polish Scientific Expedition to Peru since 2003 recognized in area of Colca Canyon and Valley of the Volcanoes high geodiversity, potential for geoturism but also requirements for protectection. The idea of creating geopark gained recently the approval of regional and local authorities with support from the local National Geological Survey (INGEMMET). The Geopark Colca and Volcanoes of Andagua would strengthen the relatively poor system of the protected areas in the Arequipa department, increasing the touristic attractiveness and determine constraints for sustained regional development.