Geohazard Research Articles

Analysis of Coir Composite In-filled Trench in Mitigating Ground Vibration

Abstract: Ground vibration is a significant geo hazard that might detrimentally affect civil engineering designs and constructions. Vibrations caused by heavy vehicles, mining railway, traffic and other construction activities have become the major reason for ground vibrations. These destructive vibrations can be isolated by providing open or in filled trench barriers as it creates material discontinuity. In this study the performance of coir composite in filled trenches in mitigating ground vibration experimentally as well as numerically by using PLAXIS 2D software is carried out by varying different parameters such as geometrical parameters, source distance, load intensities etc. It was observed that the proposed trench having coir and latex components in equal proportions can efficiently isolate the ground vibrations.

Submarine landslides in the northern South China Sea: characteristics, geohazard evaluation and perspectives

Submarine landslides in the northern South China Sea: characteristics, geohazard evaluation and perspectives

The b-value of the Kelud Volcano in the Last Three Decades

Kelud volcano is located in the Kediri sub-district, East Java Province, Indonesia. This volcano is still active, with total population, in the radius of 10 km, is around 10 thousand people. Kelud volcano is a popular tourist destination. On the weekend, total visitor can reach 5,000 people per-day. These people are at high risk when the Kelud volcano erupts. The last eruption of the Kelud volcano occurred in 2014 and was explosive eruption. Previously, there was an effusive eruption in 2007. These two types of eruption have its own geo hazard risk. Thus, predict the eruption type could help hazard mitigation. In this study, two data sets of earthquakes, 1990-2007 and 2008-2020, were analysed to determine the b-value and its relationship to the eruption type of the Kelud volcano. The calculation of the b-value uses the Gutenberg-Richter relationship. Calculation of the b-value in 2007, when there was an effusive eruption, showed a value of 2.27, while in 2014 (when there was an explosive eruption) was 1.85. After 2009, the curve of the b-value against time shows decrease. As a long term precursor of the Kelud activity, this b-value curve should be analysed continuously, besides volcano tectonic seismicity monitoring.

Analysis of the Threat of Floods in Kendal Regency Using Fuzzy Analytic Hierarchy Process and the Geo Hazard Map Methodology Catalog

Based on BPBD (2018), Kendal Regency in 2017 have occurred 154 hazards, that are 30 floods, 19 landslides, 18 fire hazards, 20 stormwind, 13 marine accidents, and 54 other hazards. Most of the Kendal Regency area is dominated by floods hazard. Disaster management can be followed up with the initial stage in mapping of hazard threats. The methods that used in mapping of hazard threats are varied depending on the hazard parameters used. In this study, using two methods to analyze the threat of floods using Fuzzy Analytic Hierarchy Process and The Geo Hazard Map Methodology Catalog. Analytic Hierarchy Process (AHP) is a decision support method to determine priority of hierarchy with the main input based on experts. Fuzzy Analytic Hierarchy Process is an Analytic Hierarchy Process (AHP) method, that developed with fuzzy logic theory, especially triangular fuzzy which is expected to minimize uncertainty so that the results wpuld be more accurate. The results in this study can be used as input for the authorities to undertake preventive hazards management.

Integrated Geo Hazard Management System in Cloud Computing Technology

Geo hazard can result in reducing of environmental health and huge economic losses especially in mountainous area. In order to mitigate geo-hazard effectively, cloud computer technology are introduce for managing geo hazard database. Cloud computing technology and it services capable to provide stakeholder's with geo hazards information in near to real time for an effective environmental management and decision-making. UNITEN Integrated Geo Hazard Management System consist of the network management and operation to monitor geo-hazard disaster especially landslide in our study area at Kelantan River Basin and boundary between Hulu Kelantan and Hulu Terengganu. The system will provide easily manage flexible measuring system with data management operates autonomously and can be controlled by commands to collects and controls remotely by using “cloud” system computing. This paper aims to document the above relationship by identifying the special features and needs associated with effective geohazard database management using “cloud system”. This system later will use as part of the development activities and result in minimizing the frequency of the geo-hazard and risk at that research area.

Geohazard assessment along the road alignment using remote sensing and GIS: Case study of Taplejung-Olangchunggola-Nangma road section, Taplejung district, east Nepal

Landslides and roadside slope failures resulting in road blockage, damage and economic losses are regular phenomena in the mountain regions of Nepal. Road construction in the northern belt of Himalaya is a challenging task, mainly due to the anticipated geo hazard in the region and remoteness of the area. The situation is often intensified in the region due to limited engineering geological and geotechnical information. The geo disaster risk further increases due to road construction. Geo hazard assessment is prerequisite to have best road alignment in mountain areas that are basically landslide-prone in many cases. The products of space science (like satellite imageries) could be a better choice for this purpose because of availability of high resolution imageries and their ready availability. The data acquired from space borne technology can be used to better assess the geological hazard condition along the road alignment. The present paper focuses to this aspect with the case study of a road section of Taplejung-Olangchunggola- Nangma, reaching the Nepal-Tibet border. The geo hazard assessment along the road corridor has been carried out through extracting the relevant information from satellite images in addition to the use of available secondary information as well as field study. A GIS database has been developed with the required information, which was used to prepare various thematic layers (like geology, drainage density, slope, aspect, rainfall), followed by further analysis. The suitability of the existing alignment has been evaluated with respect to the geo hazard condition along the road alignment.

MARINE GEO-HAZARDS IN THE COASTAL AND OFFSHORE AREA OF SOUTHERN SHANDONG PENINSULA

With the development of ocean exploration and utilization,the ocean countries are struggling for implementation of new ocean strategies.As one of the natural disasters,marine geologic hazards have raised great attention recently from governments and the public.Based on the approximately 3 000 km of high resolution shallow seismic profiles,recently acquired from the coastal and offshore area of southern Shandong Peninsula,this paper deals with the main potential marine hazardous geological factors with special emphasis on the distribution,formation,risk and burial characteritics of some of the factors,such as irregular bedrock,burial paleo-channel,shallow gas and fault.Meanwhile,the geohazard map of the study area has been completed.The scientific information incurred could be used for marine resource exploitation and engineering construction.

DEEPWATER WELL SITE ENGINEERING GEOHAZARD EVALUATION USING 3D SEISMIC DATA

With rapid deepwater oil and gas exploration and development,the accidents of drilling often occur because of geological hazard.According to statistics,30 percent cost of deepwater drilling has been spent on the accidents caused mostly by geological hazard.Actually,the accidents could be avoided through making a survey of well site prior to drilling to identify potential hazards.In this paper,well site engineering geohazard is studied through 3D seismic data for the purpose of oil and gas exploration,which is processed in 2D high resolution way.These geohazards include seafloor landslip,shallow fault,shallow gas,gas hydrates,shallow water flow,old channel,mud diapir,mud volcano,and overpressure,etc.The results of study show that the geological information derived from 2D high resolution seismic data which are picked and processed from 3D seismic data,is sufficient for evaluation of deepwater well site engineering geohazard.

The GIS Technique and Method for Sharing Information about Geo Hazard and Land Slide in Agricultural Area

The GIS Technique and Method for Sharing Information about Geo Hazard and Land Slide in Agricultural Area

Risk analysis system of geo—hazard based on GIS technique

The socio-economic attribute of geo-hazard made us distinguish it from the traditional engineering geology study. It will get more social benefit from the analysis of the geo-hazard in the socio-economic attribute. The hazard and the vulnerability of the element controls the risk level of the regional geo-hazard. The risk analysis supported by GIS in geo-hazard study is one of the most important directions. Based on the author’s studies in recent years, a risk analysis system of regional geo-hazard (RiskAnly) has been developed on the basis of software MAPGIS. The paper introduces the train of system design, the structure and the workflow of RiskAnly. As a case study, the paper also deals with the risk zonation of the regional landslide hazard of China.