Tsunami risk levels mapping in Puger Sub-District, Jember Regency

Puger sub-district is categorized as a tsunami-prone area because of its location in the South Coast, directly facing the Indian Ocean, which is the meeting point for two active tectonic plates. The active plate zone is prone to causing earthquakes that raise tsunamis. This article will describe the tsunami hazard and vulnerability level in Puger sub-district using the Geographic Information System (GIS) application. The method in this study uses a weighted overlay method. The weighting method is carried out to determine the level of tsunami hazard and vulnerability by following the weighting criteria in previous studies. Physical vulnerability criteria include land elevation, slope, beach type, land use, coastline distance, and rivers. The tsunami hazard level is determined based on the tsunami run-up map from previous studies. Based on the results of the risk mapping, it was found that there were five risk categories in Puger sub-district, namely the very low level (13.90 Ha), low level (271.99 Ha), medium level (7133.25 Ha), high level (644.22 Ha), and very high level (23.29 Ha).

Hydrogeological processes and phenomena and assessment of their danger

In modern complex engineering-geological conditions of cities, the growth and scale of development of dangerous natural processes and phenomena can be traced. In many ways, the reasons for this are not only technogenic load on the soil, but also changes in climatic factors. Buildings and objects exposed to hazardous factors of hydrogeological processes are becoming increasingly vulnerable to their impact, which can lead to catastrophic consequences. One of the main conditions for increasing the stability of objects is the adaptation of existing methods or approaches to assessing natural hazards that have a negative impact on the physical state of such objects. The authors of the article propose an adaptation of the international INFORM approach in order to assess the hazard level of natural processes and phenomena in built-up areas. The task is also to develop a methodology for assessing the physical state of objects exposed to such processes and phenomena. To solve this problem, the study examines the practical aspects of applying the principles of the Weber-Fechner law in determining the state of the structural parameters of buildings that are under the influence of negative factors of hazardous natural processes and phenomena. The study is based on the principle of changing the category of the physical state of objects from changes in the level of exposure to hazardous factors of natural processes and phenomena.

Risk analysis of landslide as a basis of mitigation plan: a case study of Mangunan Village, Bantul, Indonesia

When rainy season comes, in Mangunan Village, landslide occurs frequently. Mangunan is one of the villages in Bantul District that possesses high intensity of landslide events. Located in a contoured hilly area on the eastern region of Bantul District is one of the reasons. This study aims to analyze the risk of landslide in Mangunan by detailing the risk map, which constitutes a general risk map, and to identify the number of households that are currently residing in each risk-zone area. In this study, we applied a descriptive method that combined both qualitative and quantitative approaches in order to generate a good depiction of settlements in each risk-zone area. The data of this study can be classified into two categories, primary and secondary data. Primary data were obtained from field activities such as interviews and field documentation. Meanwhile, secondary data were obtained from archives, notes, or reports from related agencies. The results of this study are: 1) the number of settlements that are located in high- and medium-vulnerability areas are 143 and 12, respectively; 2) Mangunan Village possesses high hazard level, medium to high vulnerability level, and high-capacity level which means the village has medium to high risk level; 3) Recommendations of infrastructure development for landslide mitigation.

Assessment of landslide risk in the mountainous area. Case study: Bumiaji Sub-District

Throughout 2016-2021, there were 31 landslides that have caused physical, economic, and social damages. Bumiaji Sub-District has several tourist destinations that are potentially exposed to landslides. This study aims to create a landslide risk map in Bumiaji Sub-District. This research was conducted during the COVID-19 pandemic situation. Therefore, the data collected was secondary data obtained from Google satellite images, Google Street View, the digital elevation model from the National Geospatial Institution, and other literature reviews. The data was then analysed using a landslide risk assessment based on Perka BNPB Number 2/2012. The results of this risk analysis show that Bumiaji Sub-District is dominated by low-level risk (48%), followed by high-level risk (30%), and medium-level risk (15%). High-risk level is affected by high hazards and vulnerabilities, especially in Giripurno Village. High hazard level is affected by high intensity of rainfall, slope degree, the sensitivity of soil to erosion, and the type of land cover. High vulnerabilities are affected by physical, social, and economic aspects susceptible to losses.

Hazard Level of Slum Areas in Palembang City

The study aimed to identify the hazard level distribution in the slum areas in Palembang City. The research was a quantitative type with 382 families that live in the slums as the samples. The data were collected using proportional area random sampling and analyzed using the K-means Cluster test through SPSS 23. Spatial analysis through Arcgis was conducted to complete the understanding of the hazard distribution in the slum areas. The results showed that the hazard clusters formed by 64 areas could be categorized into three: low, medium, high. High level of hazards, reaching the one-third portion of the areas, dominated the slums in Palembang City. The cluster with a high hazard level was mostly in the city center, which was geographically located on the riverbanks, causing the areas to be vulnerable to flood, diseases, and crimes. The city center was known to offer high numbers of the job vacancy. People in the slums working in the city center were day laborers.

A Study of the Hazard Level and Vulnerability of the Society Against Debris Flow of Merapi in the Putih River Watershed, Indonesia

Mount Merapi is one of the most active volcanoes in Indonesia with a relatively fast period of around 2-7 years. The impact of hazards arising from a fire eruption, such as primary hazards, namely hazards that occur directly, secondary hazards, namely hazards that occur indirectly or take place after an eruption, tertiary hazards, namely environmental damage around the volcano. This study aims to determine the value of the hazard level and vulnerability to debris flow in the Putih River watershed. The research method used in this study is to use the scoring and weighting method. The results obtained from the scoring and weighting methods, Srumbung and Mranggen villages have a debris flow hazard with a total value of 2.6 which falls into the high hazard level category. The results show that Srumbung Village obtained a total value of 7.92 which is included in the medium level of vulnerability category. Parameters that have a big influence on the level of community vulnerability to debris flows in the two villages are social aspects with a value of 3 and economic aspects with a value of 2.4.

Strategies to enhance community capacity on reducing landslides risk at Ngargoyoso District, Karanganyar Regency

Ngargoyoso District, Karanganyar Regency Central Java Indonesia is categorized as vulnerable area for landslides. This area is characterized with high slope and its soil has texture and structure which easy to slide and erosion. The purpose of this study was to formulate a strategy to increase the community capacity on reducing regional and morphological risks of development in accordance with area functions, landslide susceptibility and soil erosion hazard level. The data used in this study was primary data, obtained through interviews with farmers and agricultural extension workers. Respondents were purposively selected with certain criteria. Qualitative descriptive approach and SWOT analysis were employed for data analysis. Strategies formulated were: 1) community needed to increase knowledge to understand environmental risks; 2) community motivation needed to create sustainable environment; 3) importance of environmentally friendly tourism management. The expected implementation of the current result is that community need to depend on the sustainable agricultural sector for their livelihood. Communities can reduce the risk of landslides that can harm their live in material and non-material aspect.

The decision support system for conducting fire-prevention measures in woodlands

Purpose of the work is to propose provisions for the aggregation of parameters of a climatic and anthropogenic nature. Regulations are necessary to determine the rating of forest areas in terms of fire hazard level. As a result of the study, theoretical provisions for the aggregation of variables have been proposed. Variables are described on different metric scales and affect the final result in different ways. The provisions are based on the methods of the theory of fuzzy sets and fuzzy inference. The computational complex for determining the rating of the forest areas is implemented in the form of a hierarchical system of fuzzy inference. It is based on the Takagi-Sugeno algorithm. Simulation of the complex operation was carried out. As a result, it was concluded that the generated output pattern has a stepped nature. This makes it possible to classify the analyzed elements into state groups. This allows you to solve the problems of planning work on the implementation of preventive and/or preparatory measures to eliminate or prevent forest fires. The prospect of further research is the formation of decision support systems in the control processes organization of forest areas.

Mining-Induced Seismicity during Development Works in Coalbeds in the Context of Forecasts of Geomechanical Conditions

Mining-induced seismicity in the area of development works and proper mining operations is one of the major determinants of the rockburst hazard level in underground mines. Rockburst hazard assessment in Polish collieries is performed by a variety of mining and geophysical methods, including seismic and seismoacoustic techniques, borehole surveys, small diameter drilling, rock strata profiling and analyses of geomechanical properties of rocks, geological structure and geological mining conditions. In the case of zones particularly exposed to potential hazards, it is recommended that analytical or numerical forecasts of the state of stress in the vicinity of workings should be used already at the stage of planning of mining operations. This study summarises the comparative analysis of seismic test data and analytical forecasts of the state of stress in five selected headings in one of the burst-prone collieries within the Upper Silesia Coal Basin in Poland (USCB). As regards the seismic data, duly defined quantitative indicators and energy criteria of the registered seismic activity are recalled in the assessment of rockburst hazard level during the roadheading operations. Analytical simulations utilise a developed geomechanical model and stress–strain relationships stemming from the principles of elastic media mechanics. From the standpoint of mining engineering practice, interpretation of results obtained by the two methods reveals how effective analytical models will be in prognosticating or verification of rockburst hazard conditions.