Genesis Of Landslides Research Articles

SCALES OF DISTRIBUTION AND ACTIVITY OF MANIFESTATIONS OF LANDSLIDE PROCESSES IN KABARDINO-BALKAR REPUBLIC

results of systematization and analysis of various sources containing information on scales of distribution and activity of manifestation of landslide processes in Kabardino-Balkar Republic are considered. It is shown that landslide activity in the republic is controlled by the climatic conditions (heavy rains, snow cover and glacier melting, river erosion) and engineering and economic development. Set of major factors of the natural and technogenic environment and degree of their influence on landslide activity differ by years. Conducted analysis of landslide activity in the republic for the last 15 years showed that the greatest degree of landslide activity was noted in 2012–2014, the smallest — in 2007. Results of estimating the scales of landslide distribution in the territory of the republic are presented including the map form. Analysis of the most significant landslides occurred in 2004–2018 and consequences of their manifestation is carried out for the main river basins (Malka, Baksan, Chegem, Cherek) of the republic. Most often landslide deformations occur due to the undercutting of slopes by highways. For each main river basin of the republic the general data on the landslide genesis, dynamic state, composition of landslide rocks, minimum and maximum values of area, volume and thickness are given. For each altitude zone (foothill, low-, medium- and high-mountain) of the main river valleys of the republic the most dangerous landslides are defined. Data on their sizes, volume and intensity of activization are given.

Cartografía morfogenética e identificación de procesos de ladera en Teziutlán, Puebla

Como consecuencia de las lluvias extraordinarias de octubre de 1999, varios desastres asociados a la inestabilidad de laderas ocurrieron en el estado de Puebla. De manera especial, Teziutlán fue fuertemente afectado por varios movimientos complejos, con mecanismos de deslizamiento y flujo. Uno de estos procesos de ladera sepultó varias casas, ocasionando la pérdida de más de 100 vidas humanas y cuantiosos daños a la infraestructura local. Este trabajo presenta una caracterización de la génesis y dinámica de los procesos de ladera ocurridos en Teziutlán, e incluye la elaboración de un mapa geomorfológico. En este último, se identifican las principales unidades morfogenéticas, a partir de las cuales es posible distinguir las zonas de mayor ocurrencia de procesos de remoción en masa. Para ello se integraron registros de los eventos de octubre de 1999 en la Sierra Norte de Puebla, lo cual permitió evidenciar las zonas más susceptibles, en función de la composición de los materiales y la morfología. Los resultados muestran que alrededor del 90% de los procesos registrados en octubre de 1999 en esta zona ocurrieron en la unidad denominada rampa piroclástica.

Some aspects of anthropogenic influences on the landslide genesis on the territory of municipality of Jagodina

The influence of anthropogenic factor on the landslide genesis is analyzed in this paper. Buildings, traffic, water supply and electro infrastructure are introduced in natural landscape as the result of human, living and economic activities in space. The conditions and processes which these objects can cause on the relation object-relief, and therefore initiate the occurrence of landslides, are the change of morphometric characteristics and the modifications of the water balance of slope. The zone with both qualitative and quantitative transformations of relief represents interactive zone in which the influence of man as a genetic factor or modifier of this colluvial process can be observed. .

Giant ancient landslide in the Alma water gap (Crimean Mountains, Ukraine): notes to the predisposition, structure, and chronology

Large-scale ancient landslides of the area of more than 5 km2 and volume exceeding 200 × 106 m3 are characteristic features of the valleys incised in the northern periphery of the Crimean Mountains (Ukraine). The largely affected area is located in the outermost cuesta range of the Crimean Mountains which consists of rigid Sarmatian limestones overlying weak Middle Miocene and Upper Palaeogene deposits. A giant landslide arose in the Alma water gap as a reflection of several coincident preparatory factors such as suitable bedrock stratification, smectite-rich bedrock exposed to swelling activity, presence of faults parallel to the valley trend, and river capture event which preceded the landslide event. The occurrence of such ancient megaslides is particularly interesting in the area which is characterized by low precipitation (<500 mm/year) and weak contemporary seismicity. It probably reflects a more dynamic environment in humid phases of the Holocene; however, seismic triggering along the Mesozoic suture zone cannot be rejected. Compressional features such as gravitational folds in the central and distal parts of the landslide, which probably correlate with the whole landslide genesis or its significant reactivation, arose, according to the radiocarbon dating, during the Holocene climatic optimum in the Atlantic period. The slope deformation has been relatively quiescent since that time, except minor historic reactivization which took place in the frontal part of the landslide. We suppose that the studied landslide could be classified as a transitional type of slope deformation with some signs of spreading and translational block slides.

Tectonic predesign of mass movements, with examples from the Chinese Himalaya

The genesis of landslides has traditionally been ascribed essentially to exogenic, nontectonic causes. Thus, it has generally been assumed that progressive erosion oversteepens slopes until they become unstable and collapse by forming slides; the specific triggers in each case would be exogenic influences such as, for instance, an extreme weather period. This paper shows that in practically all cases of mass-movements, endogenic processes are also of fundamental importance. In the first place, a landscape responds as a complex open system existing in a quasi-stationary state at the edge of chaos in which an endogenic input and exogenic outflow of mass and energy occur; this quasi-stationary state can become unstable resulting in landslides. In the second place, a direct predesign is present because of endogenic causes, viz. by a former or the present geotectonic stress field. Thus, some common notable contentions regarding the origin of landslides are shown to be false. A better understanding of the mechanisms for landslide genesis is illuminated using examples from the Chinese mountain ranges at the east end of the Himalayas. In these particular cases, the orientations of mass movements are directly controlled (`predesigned') by the present-day local tectonic stress.

A contribution to the problem of morphogenetical principles of landslide mapping

Cartographic aspects of the so far employed symbols for landslide elements are considered. Emphasis is placed on the lack of literature on how to identify particular landslide elements under field conditions and how to map them by means of appropriately selected symbols. Based on a simple landslide of earthflow type, the method is discussed for passing from cognition of landslide genesis to its cartographie description. The authors suggest to elaborate an atlas of landslide elements for engineering purposes.