The current study presents a novel combination of artificial neural network cross-validation (fourfold ANN-CV) with a hybrid analytic hierarchy process-Technique for Order of Preference by Similarity to Ideal Solution (AHP-TOPSIS) method to improve the earthquake risk assessment (ERA) and applied it to Aceh, Indonesia, to test the model. Recent studies have suggested that neural networks improve probability mapping in a city scale. The network architecture design with probability index remains unexplored in earthquake-based probability studies. This study explored and specified the major indicators needed to improve the predictive accuracy in probability mapping. First, probability mapping was conducted and used for hazard assessment in the next step. Second, a vulnerability map was created based on social and structural factors. Finally, hazard and vulnerability indices were multiplied to produce the ERA, and the population and areas under risk were calculated. Results show that the proposed model achieves 85.4% accuracy, and its consistency ratio is 0.06. Risk varies from very high to high in the city center, approximately covering an area of 23% (14.82 km2) and a total population of 54,695. The model's performance changes on the basis of the input parameters, indicating the selection and importance of input layers on network architecture selection. The proposed model is found to generalize better results than traditional and some existing probabilistic models. The proposed model is simple and transferable to other regions by localizing the input parameters that contribute to earthquake risk mitigation and prevention planning.

Integrated ANN-cross-validation and AHP-TOPSIS model to improve earthquake risk assessment

Kirchoff's Law, as originally conceived, applies only to samples in thermal equilibrium with their surroundings. Most laboratory measurements of emissivity only approach this condition and it never applies in remote sensing applications. In particular, the background is often much cooler than the radiating sample, and this has led to a long controversy about the applicability of Kirchhoff's Law under such conditions. It has also led to field and laboratory measurement techniques that use some form of the 'emissivity box' approach, which surrounds the sample with a background as close as possible to the sample temperature. In our experiments, we have heated soil samples in air on a hot plate in the laboratory to a much higher temperature than the room temperature background. Spectral emissivity was measured, except the known emissivities of both the primary and secondary Christiansen features were used, instead of assuming an emissivity of unity at these wavelengths. The results from this investigation are discussed in brief.

Thermal infrared remote sensing and Kirchhoff's law: 1. Laboratory measurements

Urban trees have the potential to mitigate some of the harm brought about by rapid urbanization and population growth, as well as serious environmental degradation (e.g. soil erosion, carbo...

/pdf/urban-tree-classification-using-discrete-return-lidar-and-an-533wsv3ruq.pdf

Urban tree classification using discrete-return LiDAR and an object-level local binary pattern algorithm

Selinsing Gold Mine is an active gold mine located in northwest Pahang, Peninsular Malaysia. Lithology of the area consists of low-grade metamorphosed sedimentary and volcanic rocks of Gua Musang Formation of Late PermoTriassic age. The gold mineralisation occurs in quartz veins that cut host rocks and are related to the N-S and NE-SW lateral faults and shear zones in the area. Minerals associated with gold are pyrite, arsenopyrite and traces of chalcopyrite, tetrahedrite and sphalerite. Wall rock alteration in Selinsing Gold Mine shows a direct relation with hydrothermal solution, structures, formation of quartz veins and gold mineralisation. Wall rock alterations related to mineralization are recognized from combined data from field observations, mineral alteration and trend of chemical compositions. They are silicification, sericitization and argilitization. Silicification is marked by the presence of secondary quartz and sericite, are is characterized by a decrease in K2O, Al2O3, LOI, Fe2O3 and increase of SiO2, Na2O. Argillic alteration is indicated by the development of clay minerals such as kaolinite, muscovite and quartz, accompanied by an increase in K2O, Al2O3, LOI, and a decrease in SiO2. Sericitization is characterized by the formation of sericite, clay minerals, quartz, chlorite, carbon, sulphides and minute traces of gold. This alteration is characterized by an increase of K2O, Al2O3, LOI, Fe2O3 and Mg, loss of Na2O and abrupt losses of SiO2.

http://archives.datapages.com/data/geological-society-of-malaysia/bulletins/054/054001/pdfs/75.pdf

Perubahan batuan dinding yang berkaitan dengan pemineralan emas di Selinsing Gold Mine, Pahang (IN MALAY), Wall rock alteration related to gold mineralization in Selinsing Gold Mine, Pahang

Structural field data have been widely used for geological analysis in the past decade. By contrast, structural stability analysis based on surface orientation for large discontinuity planes has received inadequate attention from researchers. This study performs structural stability analysis on Kuala Lumpur (KL) by utilizing surface orientations (1) to investigate the influence of rock stability on the development of transportation corridors and (2) to assess land and infrastructure stability by determining areas susceptible to various rock failures. Data are collected from three parts of KL (east, west and north) that represent different hilly regions. Data from the southern part of the city are not collected because its hilly regions are far from the city. Furthermore, the orientation data of bedding planes, faults and joints are grouped into sets for a thorough understanding. The computed global mean and best fit show that the overall structure of the area is dome- and basin-shaped. Kinematic analysis provides the percentage of potential risk for various rock failures. Our findings show the dominant types of rock failure with high risk around the city and the ranges of probabilities in the eastern, western and northern part of the city, which are 5.22%, 9.8% and 7.37%, respectively. Low probability of wedge sliding, high probability of flexure toppling and medium probability of planar sliding are observed. Results show that the set S(2) with dip angle 55°–60° in the east of KL; S(3), S(4) with dip angle 58°–67° and 65°–70° in the west of KL and S(2), S(6,7) with dip angle 52°–70° and 86°–90° are critical and could contribute to the slope failure risk in the future. It could be understood that rock failures can seriously influence the development of the surrounding agriculture land and infrastructures.

/pdf/geo-structural-stability-assessment-of-surrounding-hills-of-svbuxw1bag.pdf

Geo-structural stability assessment of surrounding hills of Kuala Lumpur City based on rock surface discontinuity from geological survey data

The Central Gold Belt (CGB) of Malaysia is a major host to gold deposits. Penjom, Raub, Selising and Buffalo reef are major gold mines in CGB. The study area, Selinsing gold mine, is located at the northwest of Pahang province on the lineament known as the Raub Bentong Suture. Presence of dense vegetation and cloud cover in tropical regions are main obstacles in alteration mapping using satellite imageries. In this study, Landsat 8 and ASTER level 1B images were used to map clay minerals and quartz rich zones at Selinsing gold mine and surrounding areas. Direct principal component analysis (DPCA), matched filtering (MF) and band ratio were the effective methods used in this study. High concentration of clay minerals was detected using band ratio 6/7, DPC2 and MF and ratio 14/12 was carried out to highlight quartz rich zones. The results of image processing methods were verified by in situ inspection and X-ray diffraction analyses. The results show that, in spite of limited bedrock exposure, the known gold prospects and potential areas of mineralization can be recognized by the methods employed in this study.

Kayvan Ghasemi

Papers

Spatial Identification of Key Alteration Minerals Using ASTER and Landsat 8 Data in a Heavily Vegetated Tropical Area