Mountain Disasters Research Articles

Mountain Disasters and Rescue Mechanism in Nepal

Geographically, Nepal is divided into three regions, namely; the Terai, the hills, and the mountains. Nepal is prone to many types of disasters due to the various causes and one of the main causes is its geographic setting. Some disasters and hazards are prevalent to all over the country, some are area specific. Mountain and high altitude hazards are unique in nature and have distinct features and they pose several challenges for the rescue and relief operations. Disasters in mountain regions of Nepal have multi-dimensional effects on human life, property and the environment. The paper analyzes the mountain disasters, their nature and their impacts. It also focuses on the institutional as well as legal arrangements regarding disaster rescue. For this purpose, a qualitative descriptive and analytical method is applied to achieve the desired objectives of the study. This paper depends upon the secondary source of data available in several works of literature; journal articles, books, news articles, government reports, and websites. The paper finds that the frequencies of mountain disasters are low in comparison to other parts of Nepal, but they are diverse and complex. There are institutional and legal mechanisms for disaster risk reduction, but they are not adequate to respond mountain disasters effectively. All security agencies along with private sectors involving in mountain search and rescue operations do not have sufficient mountain-specific rescue units, training, and logistics.

Detection and Monitoring of Post-Earthquake Landslides in Jiuzhaigou Using Radar Remote Sensing

Objectives On 8th August 2017, a catastrophic earthquake of Ms 7.0 struck the County of Jiuzhaigou in Sichuan Province, China. Because of its high magnitude and shallow epicenter, the earthquake caused grave casualties and property losses. Furthermore, the earthquake triggered numerous secondary mountain disasters such as rockfall and landslide. We use the synthetic aperture radar interferometry (InSAR) technique to detect post-earthquake landslides in Jiuzhaigou area. Methods Firstly, we carry out a quick detection across wide area using differential InSAR (DInSAR) technique with 6 ALOS-2 PALSAR-2 ascending images. DInSAR technique can observe the subtle deformation of landslide surface during the period between two SAR observations, so the active deforming landslides can be efficiently distinguished from stable areas. Nevertheless, the performance of DInSAR is often limited by temporal and spatial decorrelations induced by dense vegetation coverage, etc. To retrieve the temporal evolution of these landslides, detailed monitoring of specific landslides is carried out using time-series InSAR technique with 112 Sentinel-1 ascending and descending images. Time-series InSAR technique can overcome the limitation of traditional DInSAR technique in spatial-temporal decorrelation, and improve the deformation measurement accuracy. Therefore, the combination of DInSAR and time-series InSAR is adopted to accurately monitor single landslide, and efficiently detect landslides in Jiuzhaigou area. Results The results show that there are 13 landslides that can be detected by InSAR analyses in Jiuzhaigou area, including 7 landslides close to residential areas. The time series displacements retrieved indicate that several landslides have long-term linear deformations after the 2017 earthquake. These landslides severely threaten people's life and property and need to be monitored regularly. Finally, the reliability of detection results based on InSAR technology is verified by a field survey. Conclusions The results can provide key supports for the geohazard mitigation and prevention in the Jiuzhaigou scenic area. We indicate that a strategy which combines DInSAR technique with time-series InSAR can efficiently and accurately detect and monitor landslides over a wide area.

Regional Economic Impacts from Timber Check Dam Construction—A Comparison with Concrete Check Dam Construction

Recently, many mountain disasters caused by natural phenomena, such as typhoons and heavy rains, have struck Japan, where check dams are used as important disaster prevention structures. Meanwhile, increased timber use in Japan is expected to revitalize regional economies, thus drawing attention to the use of timber in check dams. However, comparisons between timber and concrete check dams, in terms of their impact on the regional economy, have been overlooked in previous studies. Therefore, targeting Akita Prefecture in Japan, we evaluated quantitatively the respective regional economic impact of timber and concrete check dam construction through an input–output analysis. An extended input–output table was developed based on the revenue and expenditure data obtained from interviews with check dam construction companies. The construction cost and amount of sediment runoff prevention of a concrete check dam was unified with those of a timber check dam to evaluate their respective economic impact. In both cases, the impact of timber check dam construction was about 12 to 13% larger. In brief, timber check dam construction was found to have a more positive impact on the regional economy than concrete check dam construction. However, with the regional self-sufficiency ratio of the lumber and wood products sector at less than 20%, or the lumber price at 60% of its current price, the economic impact of constructing a timber check dam becomes smaller than that of a concrete check dam. In other words, it is important to harvest, process, and use timber regionally to contribute to the regional economy. Specifically, using timber that is processed, rather than simply harvested, in the region has a larger economic impact on the region. Additionally, in timber check dam construction, procuring inexpensive timber and reducing construction costs may be a trade-off for revitalizing the regional economy.

Analysis of the Topography Change using the RAMMS Model and Numerical Modeling in the Korean East Sea Estuary

Choi, J.H.; Kin, S.D.; Jun, K.W.; Lee, H.J., and Tak, W.J., 2020. Analysis of the topography change using the RAMMS Model and numerical modeling in the Korean East Sea Estuary. In: Malvarez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 422–427. Coconut Creek (Florida), ISSN 0749-0208.Recently, erosion and sedimentation imbalances have occurred on many coastlines due to the complex effects of man-made environment changes and natural environment changes caused by climate change. Problems including coastal erosion, shoreline topography changes, and estuary blockages require comprehensive management of sediments including coastal sediments and those discharged from rivers and mountains in the hinterland. This study quantitatively investigated the streamflow of sediments generated from mountains and examined the effect of discharged sediments on coastlines and beaches. First, the sediments in rivers and beaches from mountain areas were investigated on-site using terrestrial LiDAR. High-precision topography data were constructed by generating Digital Elevation Model (DEM). To calculate the amount of sediment discharged from mountain areas quantitatively by using constructed topography data, simulations were performed with the RAMMS model, a type of sediment-water flow analysis model. By applying an erosion and sedimentation model, the effects on the beach topography along the coast were analyzed. It was confirmed through the RAMMS model that the sediment flowed into the river when a mountainous disaster, such as landslide or debris-flow, occurred. The sediment that flowed into the river induced coastline and beach topography changes. In terms of the beach topography on the East Coast of South Korea, the north side of the estuary beach showed a significant sedimentation tendency and the south side of the beach showed a gradual erosion tendency. Furthermore, significant changes in the coastline were observed as a river-mouth blockage occurred at the estuary due to sediments deposited from the mountains and rivers in the coastal area. It is expected that the results of this study will provide useful information when establishing plans for the preservation of coastal areas in the future.

Experimental study on the effects of tree planting on slope stability

Ecological engineering is an effective method to control mountain disasters, in which tree roots play an important role in stabilizing the slope and consolidating the soil in face of the landslide. The use of artificial roots to simulate real root is an important means of experimental research. To explore which tree planting patterns could achieve better stability on slopes of 20°, 35°, 50°, and 60° under extreme climatic conditions (rainfall intensity of 118 mm/h), this paper used an artificial root model to construct four types of slopes, i.e., slope with dense trees planted on wide bands, slope with dense trees planted on narrow bands, slope with equally and sparsely planted trees, and barren slope (control group). Sixteen groups of indoor slope rainfall experiments were carried out. To determine the stability effects of different slopes, the failure process and model of slopes during rainfall were analyzed, and the safety factor values Fs were calculated. The following conclusions are drawn: (1) Trees have different effects on the stability of slopes with different slope gradients. Planting trees on 20° and 35° slopes has good reinforcement effect, but planting trees on 50° or 60° slopes will lead to less stability. (2) The optimal planting patterns are different for different slopes. For example, the optimal planting pattern on the 20° and 35° slopes is wide-band dense planting, while it is not suitable to plant tall trees on the 50° and 60° slopes. (3) The change of slope gradient will not affect the failure mode of barren slopes but will change the failure process for vegetated slopes. (4) Wide-band dense planting pattern on all slopes can effectively intercept sediment, inhibit sediment slide, and prevent collapse. All in all, the research results provide a good theoretical guidance and practice to control landslides with ecological engineering.

Simulating the process of the Jinshajiang landslide-caused disaster chain in October 2018

A mountain disaster chain always brings about potential danger to the safety of people and the environment based on its characteristics of long time-scale, great destructive power, and broad scope. Mechanisms responsible for this hazard are represented by studying a landslide-caused disaster chain that occurred in the bank of Jinshajiang River, China on 10 October 2018. The evolution process of this disaster chain is simulated and analyzed using a coupled model that consists of several depth-averaged equations, and the results agree well with the measured data. Furthermore, several factors, including frictional coefficient, inflow flux, and critical dam slope coefficient, are tested by applying different values. Results indicate that the evolution of a mountain disaster chain can change at each stage with different initial conditions.

Simulation and test of the movement process of mixed flow composed of slurry and coarse particle

Mixed flow composed of coarse particle and mud is a common mountain disaster. Because of its typical granular material characteristics, fluid theory based on continuum hypothesis is difficult to describe discontinuous deformation. Therefore, the rotary shear and normal bonding experiments of clay mud are carried out by MCR301 to determine the mechanical parameters of the normal and the tangential direction of the mud (131% moisture content). According to the theory of granular material, with PFC3D as the platform, write the numerical viscosity slope model test programme, according to the mud test results, set the parameters of the numerical model, reproduction process and the discontinuous deformation phenomenon, and is verified by the same size physical model test. The results show that the PFC3D discrete element method based on granular material theory can well reproduce the movement process and discontinuous deformation phenomenon of the coarse particle mud mixing flow slope, and provide a new way for in-depth analysis of the complex landslide movement process.

平成28年（2016年）熊本地震によって生じた山腹崩壊

平成28年（2016年）熊本地震によって生じた山腹崩壊

Understanding sustainable disaster mitigation of stakeholder engagement: Risk perception, trust in public institutions, and disaster insurance

AbstractMany rural settlements in China's western mountainous regions are affected by mountain disasters, such as landslides and mudslides. For residents living in landslide‐prone areas, behaviors related to disaster risk mitigation (such as purchasing disaster insurance) are inevitably affected by disaster risk perception. Due to the substantial differences in disaster occurrence patterns, landslide‐related insurance research is relatively rare compared with insurance research focused on other types of natural disasters (e.g., floods and droughts). Based on the results of questionnaires administered in landslide‐prone areas in Chongqing, China, this paper uses partial least squares structural equation modeling (PLS‐SEM) to investigate the relationships among the questionnaire respondents' risk perception, trust in public institutions (TPI), and willingness to buy disaster insurance (WBDI). The results reveal that risk perception and TPI directly affect WBDI. Here, competence, participation, possibility perception, and fear perception are significantly positively correlated to WBDI, whereby fear perception has the largest impact, followed by possibility perception, competence, and participation. In addition, TPI indirectly affects WBDI through risk perception. Here, competence reduces fear perception and indirectly reduces WBDI. The implications of these results for theory are discussed. This study introduces a new method to support disaster risk mitigation‐related decision making that can be useful to governments and individuals.

Geo-environmental Quality Evaluation Based on GIS in Shiyan-Wudang Mountain Area

The Shiyan-Wudang Mountain area is located in the Danjiangkou Reservoir Area, the upper reaches of the Han River, the hinterland of the Qinba Mountain Range. The main geological environmental problems in the region include collapse, landslides, debris flow, ground collapses, and ground fissures, which seriously restrict local economic development. Based on the analysis and summary of the distribution, development characteristics, formation conditions and influencing factors of geological disasters in this area, the multiple comparisons is used to select the formation complex, slope, distance from the fault zone, water yield property, distance from surface water system, average annual rainfall, mountain disaster point density, soil erosion, and human engineering activity intensity as the evaluation indicators, the geological environment quality evaluation index system of Shiyan-Wudang Mountain area was established; Geographic information system (GIS) technology is used to carry out hierarchical management of basic maps, and establish a spatial database of geological environment conditions. The analytic hierarchy process is used to determine the weight of the index system. The evaluation module developed by MapGIS platform is used to evaluate the geological environment quality of the study area. Respectively, the area of geological environment with best quality, good, poor and worst areas accounted for 56.805%, 22.800%, 16.474%, and 3.921%. The results show that the geological environment quality of the study area is generally good, and some areas are poor, and very few are bad. The calculated evaluation map is compared with the current geological disaster points, and the results verify the accuracy and scientificity of the evaluation process and results. The research results of this paper can provide a basis for regional geological environment management, planning, disaster prevention and mitigation.

Peningkatan Self Awareness Anak Usia Dini Melalui Media Video Mitigasi Bencana Gunung Meletus

This study aims to improve children's self-awareness in disaster response, especially volcanic eruptions with result that children are able to understand the danger of volcanic eruptions since early and have an awareness through a disaster. The subjects were children in group B TK Pertiwi 1 and 2 Samiran, aged 5-6 years. The study was carried out in the village of Samiran because it was an area under the foot of Mount Merapi and Merbabu. This study uses "Action Research" with 2 implementation cycles. This uses Kemmis and MC Taggart procedure which consist of four components, includes: a) planning, b) acting, c) observing, d) reflecting The results are expected that eruption of mountain disaster mitigation videos can improve self-awareness in disaster response so that children have the provision to save themselves and preserve the environment so that the small number of victims because the understanding of disaster mitigation has been obtained since childhood early.

OPTIMIZED ORGANIZATION AND ADAPTIVE VISUALIZATION OF COMPLICATED MOUNTAIN DISASTER 3D SCENES FOR DIVERSE TERMINALS

Abstract. Mountain disaster scenes usually contains various geographical entities, which are dynamic and complicated. Therefore, the construction of mountain disaster 3D scenes has great significance for disaster simulation, analysis and prediction. 3D visualization and interactive analysis of complicated mountain disaster scenes should accommodate users who have access to various terminals in disaster emergency response. However, most of the existing 3D visualization methods can only deal with 3D scene data organization and scheduling for single terminal or limited kinds of geographical entities. Due to performance constraints, it’s difficult for Mobile devices to support efficient visualization of complicated mountain disaster 3D scenes, either. To address these issues, we research the key technologies for efficient visualization of mountain disasters on diverse terminals. We utilize the B/S architecture and research its impact on rendering frame rate and the relationship of terminal characteristics and parameters through analysis of terminal characteristics and parameters, e.g. hardware performance, screen size and resolution, network environment, and rendering frame rate requirements. Then we analyze the diverse organization of mountain disaster scene data and explore the methods of constructing efficient spatial index by taking into account the characteristics of diverse terminals. An adaptive scene analysis method is subsequently designed to select the optimal model. Finally, based on the diverse organization of various data in the scene, a corresponding dynamic scheduling method is proposed to realize the adaptive visualization of complicated mountain disaster 3D scenes for diverse terminals.

Geomorphology Characteristic and Tectonic Response of the Meijiang Watershed in the Southern China Represented by Hypsometric Integral

MeiJiang river basin was selected as study area in this paper because it is a typical representative in the mountains of south China. Firstly, the study area was classified into several catchments in ARCGIS platform based on DEM data. Secondly, this paper withdraws the measuring indicators of the geomorphology and hypsometric integral from the basins. Then we study the information of geological structure and development of disaster situation. Finally, revealing the relationship between Hypsometric Integral and tectonic activity, lithological association and disaster intensity. It provides an important theory and method for studying geomorphic spatial pattern and characteristics of development as a whole. The result indicates that Hypsometric Integral has a spatial scale effect, geomorphology, lithology and disaster development can be simulated by small watersheds. For one thing, the studying area is in the mature phase, which is a high-incidence area with many kinds of mountain disasters; for another thing, the 1erosion resistance of biotite monzonitic granite is the most strongly. On the contrary, the sandstone, conglomerate, glutenite, siltstone, mudstone and limestone of it are weakly. At last, regional tectonic activity can be reflected by the Hypsometric Integral of big watershed units.

Effects of fine particle content and sample scale on the failure properties of loose landslide deposits

A large amount of loose landslide deposits caused by a strong earthquake can cause several mountain disasters (slope failures, debris flows, and others) under heavy rainfall conditions. Loose landslide deposits are sensitive to water due to their special structural properties, such as loose structure and wide grading. There are complex conformational and mechanical responses of loose deposits, but the initial conditions and formation mechanisms of mountain disasters can be described by several different parameters. Among these parameters, the property of failure is one of the most important, and it is used to describe extremely dangerous situations for each kind of disaster. In this study, a two-dimensional particle flow code platform (PFC2D) was used to simulate the failure properties, and a laboratory test verified the validity of the numerical experiments. Different sample scales (S1, 150 × 300 mm; S2, 300 × 600 mm; S3, 600 × 1200 mm) and fine particle contents smaller than 5 mm (f-1, 20%; f-2, 30%; f-3, 40%) were considered. The simulation results show that failure stress increases with increasing sample scale or fine particle content under low confining pressure and decreases under high confining pressure. The tendency of failure stresses to vary mutates with different fine particle contents when the confining pressure changes. The mutation value of the confining pressure is 280 kPa. In addition, the phenomenon of strain softening becomes less obvious when the confining pressure increases.

RESEARCH ON THE SUITABILITY EVALUATION OF CONSTRUCTION LAND IN SOUTHWEST MOUNTAINOUS AREAS OF CHINA: A CASE STUDY OF BAOXING COUNTY, SICHUAN PROVINCE, CHINA

Currently, the threats of mountain disasters are continuously increasing due to the highly vulnerable feedback mechanism of mountain ecosystems, and the construction land use type is most strongly affected by human activities. This study uses multiple index coupling models to evaluate the suitability of construction land. The evaluation uses mountain disaster risk, topographic and geomorphic environments, hydrogeological environments, human activity factors and socio-economic factors as the suitability standards. We use geographic information system (GIS) technology to improve the evaluation model and establish a suitability map of construction land for Baoxing County, Sichuan province, China This study indicates that the mountain disaster risk is the core factor of the suitability zoning of construction land in Baoxing County, wherein, the development suitability of construction land in the central sectors is relatively high while the mountain disaster risk is relatively high due to the high socioeconomic value of the disaster-bearing areas in the central sectors. The development suitability of construction land near the fracture zones and the natural reserves is relatively low.

Development of a micro-scale CFD model to predict wind environment on mountainous terrain

The installation of an observation system on mountainous terrain is important for the observation of accurate weather information and the effective prediction of pollutant of airborne virus dispersion and mountain disaster, such as a fire or landslide. However, no Korean standard for installation of the mountain meteorological observation system exists. To determine the proper location, height and size of an observation system, a wind environment analysis under various environmental conditions should be conducted; however, field experiments have time and cost limitations. The objective of this study was to develop a micro-scale 3D Computational fluid dynamics (CFD) model to predict the wind environment on mountainous terrain. In our model, the ground surface of the CFD model was classified and designed based on a digital contour map provided by the National Geographic Information Institute (NGII) and a forest type map provided by Korea Forest Service (KFS) in order to simulate air resistance of trees from the study area. The air resistances of trees were realized as porous medium and the porosity coefficients of the trees were determined based on the previous researches. The developed 3D CFD model was validated using a distribution of wind velocity and direction data measured in mountainous terrain.

Impacts of Climate Change on Tibetan Inhabited Areas in Sichuan Province, China

Tibetan inhabited areas in Sichuan Province are part of Qinghai–Tibet region which is a unique geographic zone due to its high altitude, sparse human population and prevalent pastoral system. In the past decades, the climate in the region is becoming warmer, and this has resulted in the retreating of most glaciers, the uplifting of the snow lines, permafrost degradation, meteorological disasters and related mountain disasters are becoming more severe and frequent. Climate change may directly and indirectly affect economic outcomes in the short to longer term; it also can lead to household impacts, as well as regional impacts.

Dynamic simulation of a mountain disaster chain: landslides, barrier lakes, and outburst floods

A mountain disaster chain is a complex system that consists of several sub-disasters and can result in high casualties or serious economic loss. In this study of the mountain disaster chain linking landslides, barrier lakes, and outburst floods, a system model is presented for preliminary use. This system model consists of several depth-averaged models to simulate the movements of sub-disasters. Some factors that influence the movement of each sub-disaster are considered, such as basal pore pressure and sediment transport. Furthermore, the critical conditions that influence the transition between subordinate disaster and superior disaster are studied. To validate the feasibility of the proposed system model, the Yigong mountain disaster chain is simulated as a case study. Comparisons between field observations and numerical results confirm the validity of the model.

Analisis Foto Jurnalistik Bencana Gunung Sinabung

Analysis of Journalism Photo of Sinabung Mountain Disaster (Study On SINDOnews.com News Site) was analyzed by using Pierce semiotics that was about sign, object, and interpretant. Data sources were primary data sources (photographs) and secondary data sources (literature that supports primary data such as dictionaries, internet, theses, books). The method used in this study is a qualitative research method that is descriptive analysis, ie research that provides an objective picture, with Pierce analysis of photojournalism. Of the total images posted since April 2, 2015 to May 5, 2015. This study chose 11 representative journalistic photos. Photo journalism classified from the category of preaching photo before Mount Sinabung erupted, when the volcano erupted, the impact of the eruption of Mount Sinabung and the response from the Sinabung disaster. The conclusion of the research showed that 1. From every area rubric, most of the news published was spot news. This can be seen from the rubric of North Sumatera about Sinabung mountain disaster. 2. From the results of Pierce's semiotics analysis on the SINDOnews.com news site about Sinabung mountain disaster, obtained that each photo displayed must have their respective elements, especially for the caption element, should be more.

Spatial-Temporal Dynamic Monitoring of Vegetation Recovery After the Wenchuan Earthquake

Mountainous vegetation recovery after major earthquakes has important implications for preventing postseismic soil erosion and geo-hazards. However, regional recovery processes of the postseismic vegetation and its spatial patterns have not been thoroughly studied. In this paper, we examined the vegetation recovery processes following the 2008 Wenchuan earthquake (Ms. 7.8) using 16-day interval MODIS normalized difference vegetation index time series from 2000 to 2014. The Savitzky–Golay filter and cross-correlogram spectral matching were used to eliminate the influences of cloud and intraannual phenology. Change vector analysis was applied to measure the postseismic vegetation recovery conditions for each year. We find that the heavily affected vegetation areas are mainly located along the southern part of the earthquake surface rupture. Additionally, five major affected vegetation types have been identified: shrubland, grassland, broadleaf/mixed, needleleaf, and plantation. Shrubland represents the largest fraction of vegetation type in the heavily affected area, whereas plantation comprises the smallest fraction of vegetation type in the heavily affected area. Further analysis indicates that the changing trend of postseismic vegetation conditions in the first six years can be grouped into three classes: recovering, fluctuating, and deteriorating. Recovering and fluctuating classes cover 59% and 37% of the heavily affected areas, respectively, and are the two dominant postseismic vegetation classes. In contrast, the deteriorating recovery class covers just 4% of the affected areas. The recovering vegetation is primarily located around the epicenter, and most of the fluctuating classes is located to the northeast of the epicenter. These results demonstrate that the Wenchuan earthquake has long-term and important influences on mountain vegetation, and more attention should be given to the locations of deteriorating and fluctuating vegetation following mountain disasters.