[en] In the paper, the landscape-geographic disasters, caused by natural spontaneous events (landslide-gravitational, mudflow, rock fall, snow slides), are considered. It has been noted that at such locations, the use of constant monitoring and creation of a single system of communications plays an important role in the activity of state institutions and organizations, the operation of which is associated which controls natural disasters or is used for reduction of the negative effects caused by catastrophic events. (paper)

[en] A forest buried at 1630-1730 cal. BP has been exhumed by incision of Miller Stream, a tributary of Clarence River that drains the steep southeast flank of the Seaward Kaikoura Range, Marlborough, New Zealand. The paleoforest is exposed along several hundred metres of the modern channel of the south branch of Miller Stream, and comprises over 40 tree stumps in growth position that are up to 2.5 m in circumference and 2 m in height. Just over 2 km downstream, subhorizontal trees of the same age as the paleoforest are buried by c. 14 m of a fining upward, poorly sorted 'debris flow' deposit containing clasts as large as 2 m diameter. This deposit is capped by c. 8 m of thickly bedded alluvial deposits. The aggradation that inundated Miller Stream, and buried the forest, was probably caused by a large rock avalanche in its headwaters with an estimated volume of c. 3.7 x 10⁷ m³. The triggering mechanism for the Miller Stream rock avalanche has yet to be established; however, given its large size, the depth of its source scar (greater than or equal to 100 m), and its close proximity (within 15 km) to at least five major active faults (Jordan Thrust, Fidget, Kekerengu, Hope, and Clarence faults), we suggest that an earthquake may have been the trigger. (author). 11 refs., 5 figs., 1 tab

[en] The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently durable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System for ground control installation

[en] New radiocarbon ages for wood samples retrieved from the base of the Acheron rock avalanche near Porters Pass, Canterbury, show a clustering of ages between 1370 and 1101 yr BP. This is significantly dissimilar to the established radiocarbon age of 500 ± 69 yr BP (NZ547), from weathering-rind thickness measurements and from lichen studies. This contradiction impacts on current calibrations of lichenometric and weathering-rind dating methods, which has serious implications for landslide and earthquake dates based on them. A 500-600 yr BP earthquake event along the Porters Pass-Amberley Fault Zone has been dated in an adjacent trench and is consistent with previous dates but does not correspond to the Acheron rock avalanche emplacement as previously proposed. The landslide may have been caused by either a Porters Pass Fault event (1100-800 yr BP) or by the better-constrained Round Top event (1010 ± 50 yr BP) on the Alpine Fault. (author). 30 refs., 13 figs., 2 tabs.

[en] Landslides and rockfalls that initiate on a steep slope eventually come to rest after flowing for some runout distance on a flat. Rockfalls of very large masses have been observed to exhibit unexpectedly long runout distances. This problem becomes more significant as the development of resources in mountain regions becomes more intensive. As early as 1881, Albert Heim observed and described the Elm rockfall of Switzerland (quoted by as HsU). This rockfall produced a debris which moved more than 2 Km along a nearly horizontal valley floor and one of its branches surged up the side of the valley to a height of 100 m. From the deposit of the Elm and the eyewitnesses Heim concluded that the debris behaved as a flowing fluid rather than sliding solids. Davies, among others, suggested that the excessive runout distance is volume dependent and the larger the volume of the debris, the longer the relative travel distance. A summary of the numerous hypotheses which have been proposed to explain this puzzling phenomena were also presented by Davies. However, none of these have been completely satisfactory or generally accepted. A simple model of the flow and spreading of a finite mass of cohesionless granular material down incline has been developed as a part of the present preliminary investigation into the mechanics of rockfalls. (author)

[en] Rockfalls influence the safety of the surrounding infrastructure and the normal operation of transportation lines. The application of synthetic aperture radar (SAR) technology is a new method of rock-fall monitoring and disaster prediction. This paper proposes a new method of dynamic monitoring and parameter estimation for rockfalls based on a multichannel airborne SAR system. First, the signal model of the multichannel airborne SAR system is derived. Then, to improve performance, the traditional displaced phase centre antenna (DPCA) method is extended to three or more receiver channels. This method can be effectively applied for rock-fall target detection, as well as to precisely estimate rock-fall target parameters and resolve the ambiguity issues associated with the estimation of rock-fall target parameters. Finally, simulation results are used to validate the proposed approach.

[en] The outputs from the drift degradation analysis support scientific analyses, models, and design calculations, including the following: (1) Abstraction of Drift Seepage; (2) Seismic Consequence Abstraction; (3) Structural Stability of a Drip Shield Under Quasi-Static Pressure; and (4) Drip Shield Structural Response to Rock Fall. This report has been developed in accordance with ''Technical Work Plan for: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The drift degradation analysis includes the development and validation of rockfall models that approximate phenomenon associated with various components of rock mass behavior anticipated within the repository horizon. Two drift degradation rockfall models have been developed: the rockfall model for nonlithophysal rock and the rockfall model for lithophysal rock. These models reflect the two distinct types of tuffaceous rock at Yucca Mountain. The output of this modeling and analysis activity documents the expected drift deterioration for drifts constructed in accordance with the repository layout configuration (BSC 2004 [DIRS 172801])

[en] River channels and hillslopes are shaped by the joint action of localized, vertical fluvial incision along the channel and of diffuse surface creep, landslides or rock falls on the adjacent slopes, the latter being often gathered under the generic term of hillslope processes. The interplay between river incision and hillslope processes is responsible for various landscape forms, from smooth, low-relief areas to sharp and deeply incised domains. In areas where river incision is the dominant erosive process, determining the gradual exposure of river gorge walls by cosmogenic radionuclide dating permits to estimate the long-term (several ka) local incision rate. However, strongly cohesive rocks like massive limestones or sandstones may be prone, from time to time, to abrupt and localized degradation by rock falls. On a gorge wall, besides resetting the exposure age signal on the area where a block has been detached, rock fall events also produce debris that transiently protect the bedrock from river incision and the bottom of the gorge wall from cosmic radiations. In some extreme cases, rock fall events can even lead to the formation of epigenetic gorges. Although gorge walls appear as good markers of river incision, the random occurrence of rock falls may therefore add complexity to the interpretation of exposure ages, to the point where the actual river incision imprint is barely discernable. In this presentation, we simulate the 1D evolution of topography and Cosmogenic Radionuclides Exposure (CRE) ages on a gorge wall progressively formed by river incision and randomly reshaped by rock falls, in order to evaluate the imprint of these events on the CRE signal. We then discuss the implications of these models on the sampling strategy and on the interpretation of previously dated river gorges in the Southern French Alps and Provence.

[en] Few studies have been conducted for susceptibility of rock falls in mountainous areas. In this study, we compare and evaluate rock fall susceptibility mapping using bivariate statistical [weight of evidence (WoE)], analytical hierarchy process (AHP) and frequency ratio (FR) methods along 11 km of a mountainous road in the Salavat Abad saddle in southwestern Kurdistan, Iran. A total of 34 rock fall locations were constructed from various sources. These rock fall locations were then partitioned into a training dataset (70% of the rock fall locations) and a testing dataset (30% of the rock fall locations). Eight conditioning factors affecting on the rock falls including slope angle, aspect, curvature, elevation, distance to road, distance to fault, lithology and land use were identified. The modeling process and rock fall susceptibility mapping has been constructed using three methods. The performance of rock fall susceptibility mapping was evaluated using the area under the curve of success rate curve for training and prediction rate curves (PRC) for testing datasets and also seed cell area index. The results show that the rock fall susceptibility mapping using the WOE method has better prediction accuracy than the AHP and FR methods. Ultimately, the weight-of-evidence method is a promising technique so that it is proposed to manage and mitigate the damages of rock falls in the prone areas.

[en] The siting process of finding and confirming a suitable site for a construction of a deep geological repository (DGR) generally consists of four main stages. It starts with a conceptual planning stage and continues with an area survey and site screening stage, followed by site investigation and characterisation stage and finishes with site selection and confirmation stage. The entire process is complex the different stages are interconnected; therefore, good planning is essential for successful implementation. In the conceptual planning stage not only the overall plan for the site selection process is prepared but also important decisions related to the siting process are taken and guidelines for the following siting stages are developed. Concerning the area survey and site screening stage, in conceptual planning stage the decision on the site selection approach is taken, criteria for assessing the suitability of potential areas and site(s) are developed and other relevant details like areas/regions to be screened, sources of information and data to be used etc. are defined. The main goal of an area survey is to screen large areas or regions (preferably the entire country) by desk studies that are based on available data and information to narrow the number and the size of search areas with a potential to host a DGR down to one or few areas with several potentially suitable sites for preliminary investigations. The screening is mainly based on exclusionary criteria and, if available, also preferential (avoidance and suitability) criteria can be used. The exclusionary criteria are mainly related to long-term safety of a repository while preferential criteria consider also construction and operational suitability and socio-political factors. Typical criteria used at this stage are seismicity, volcanic activity, flooding, tsunami, rock fall, presence of natural resources, also proximity to big cities, lack of existing transport infrastructure, areas of special cultural, scientific or ecological interest, etc. [1, 2, 3]. Areas or potential sites within these areas that do not pass the exclusionary criteria are screened out from further consideration. By using the avoidance and suitability criteria the number of remaining areas with potential sites can be further reduced. After several screening rounds a relatively small number of areas with prospective sites remains for site investigations in the next site selection stage [1, 2]. However, this approach assumes that the archived data and information on the areas and sites and literature search are sufficient for a fair comparison between the areas and sites and for performing progressive screening. If not, more detailed desk studies and additional data obtained by limited field investigations and measures might be needed.