A Case Study on the Closed-Type Barrier Effect on Debris Flows at Mt. Woomyeon, Korea in 2011 via a Numerical Approach

Debris flows are capable of flowing with high velocities and causing significant economic and infrastructural damage. As a hazard mitigation measure, physical barriers are frequently installed to dissipate the energy of debris flows. However, there is a lack of understanding on how barriers affect and interact with debris-flow behavior (e.g., velocity and volume). This study investigated the changes in debris-flow characteristics depending on the installation location of barriers. Mt. Woomyeon, which is located in Seoul, Korea, was the site of a major debris-flow event in 2011. This study modeled this event using DAN3D, numerical software based on smoothed particle hydrodynamics (SPH). Our numerical approach assessed changes in debris-flow behavior, including velocity and volume, as the debris flow interacts with four closed-type barriers installed at separate points along the flow path. We used DAN3D to model the barriers via terrain elevation modifications. The presence of a closed-type barrier results in the reduction in the debris-flow velocity and volume compared to when no barrier is present. Most notably, the closer a barrier is installed to the debris source, the greater the velocity decrease. By contrast, a barrier that is constructed further downstream allows the debris flow to undergo entrainment-driven growth before confronting the barrier, resulting in a larger debris deposition volume that can often cause overflow, as shown at our particular study site. The presented results highlight the effectiveness of barriers as a method of hazard mitigation by providing insight into how such installations can alter debris-flow behavior. In addition, the findings can provide a reference for future debris-flow barrier designs, increasing the effectiveness and efficiency of such barrier systems.

Engineering With Nature : the role of mangroves in coastal protection

The purpose of this Engineering With Nature technical note (EWN TN) is to review previous studies of mangroves as a nature-based adaptation alternative for coastal protection and flood hazard mitigation.

Earthquake Vulnerability Assessment for Urban Areas Using an ANN and Hybrid SWOT-QSPM Model

Tabriz city in NW Iran is a seismic-prone province with recurring devastating earthquakes that have resulted in heavy casualties and damages. This research developed a new computational framework to investigate four main dimensions of vulnerability (environmental, social, economic and physical). An Artificial Neural Network (ANN) Model and a SWOT-Quantitative Strategic Planning Matrix (QSPM) were applied. Firstly, a literature review was performed to explore indicators with significant impact on aforementioned dimensions of vulnerability to earthquakes. Next, the twenty identified indicators were analyzed in ArcGIS, a geographic information system (GIS) software, to map earthquake vulnerability. After classification and reclassification of the layers, standardized maps were presented as input to a Multilayer Perceptron (MLP) and Self-Organizing Map (SOM) neural network. The resulting Earthquake Vulnerability Maps (EVMs) showed five categories of vulnerability ranging from very high, to high, moderate, low and very low. Accordingly, out of the nine municipality zones in Tabriz city, Zone one was rated as the most vulnerable to earthquakes while Zone seven was rated as the least vulnerable. Vulnerability to earthquakes of residential buildings was also identified. To validate the results data were compared between a Multilayer Perceptron (MLP) and a Self-Organizing Map (SOM). The scatter plots showed strong correlations between the vulnerability ratings of the different zones achieved by the SOM and MLP. Finally, the hybrid SWOT-QSPM paradigm was proposed to identify and evaluate strategies for hazard mitigation of the most vulnerable zone. For hazard mitigation in this zone we recommend to diligently account for environmental phenomena in designing and locating of sites. The findings are useful for decision makers and government authorities to reconsider current natural disaster management strategies.

Preface

The Faculty of Social Sciences, Universitas Negeri Yogyakarta in collaboration with the Department of Geography of the Universiti Pendidikan Sultan Idris (UPSI) Malaysia, the Geography Department of Chulalongkorn University (CU) Thailand, the Geography Department of the University of Muhammadiyah Surakarta (UMS) Indonesia, and the Indonesian Geographical Association held The 2nd International Conference on Hazard Mitigation in Geographic and Education Perspectives (The 2nd ICHMGEP) on "Disaster Management for Enhancing Resilience, Risk Reduction and Sustainable Development Goals". This conference continues the tradition of scientific meetings (The 1st ICHMGEP) organized in 2018, which successfully gathered hundreds of participants and published conference papers in international publication outlets. The 2nd ICHMGEP 2020 provides a platform for researchers, lecturers, students, practitioners, and scientists to showcase their latest findings in areas of expertise, including geoscience, environment, science and technology innovation, mapping, and technological innovation. In addition, it aims to disseminate original research results, new ideas, innovations, practical experiments to promote scientific progress and achieve sustainable development goals. The 2nd ICHMGEP 2020 had formerly been planned to be organized in an offline format. However, it was conducted online on September 11-12, 2020 mainly due to the Covid-19 pandemic impacts. The increasing number of Covid-19 positive cases in Yogyakarta Province since March 2020 forced the government to carry out various restrictions on activities gathering many people like a conference. This is supported by the issuance of the Covid-19 emergency response period in Yogyakarta, Indonesia from March 20 - May 29 2020. Moreover, the emergency response period was extended on May 30 - June 30 2020, 1 - 31 July 2020, 1 - 31 August 2020, and 1 - 30 September 2020. In addition, the Covid-19 pandemic offered uncertainty and was difficult to be predicted when it would end. Therefore, the organizing committee decided to change the offline format into an online format as the conference would provide great benefit for the wider community including giving solutions to cope with covid-19 related problems. Also, many supportive platforms such as zoom dan live youtube could facilitate the implementation of the online conference List of Rundown The 2nd International Conference On Hazard Mitigation In Geographic And Education Perspectives (ICHMGEP) 2020, Room Distribution For Parallel Session 12 September 2020, Platform: Zoom, Images, Committee of The 2nd ICHMGEP 2020 are available in this pdf.