Tag: hazard

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Understanding Sinkhole Susceptibility in Kuala Lumpur and Ampang Jaya: A GIS and AHP-Based Approach

Sinkhole Risk Mapping with GIS and AHP: Kuala Lumpur and Ampang Jaya Case Study

Introduction

Sinkholes are a significant geohazard, particularly in urban areas like Kuala Lumpur and Ampang Jaya, where the increasing number of incidents has raised concerns over public safety and urban infrastructure. Since 1968, the Klang Valley region has witnessed a growing frequency of sinkholes, posing serious threats to human lives, assets, and structures, particularly in Malaysia’s bustling capital. To address this issue, Rosdi et al. (2017) conducted a study that employed Geographic Information Systems (GIS) integrated with the Analytical Hierarchical Process (AHP) to develop a Sinkhole Hazard Model (SHM). This article discusses the findings of this study, the methods used, and the potential for future research in this critical area of disaster management.

Sinkhole Susceptibility Hazard Zonation

The SHM developed by Rosdi et al. (2017) categorizes the study area into five zones of sinkhole susceptibility: very low, low, moderate, high, and very high hazard. These classifications are based on a combination of five key criteria: Lithology (LT), Groundwater Level Decline (WLD), Soil Type (ST), Land Use (LU), and Proximity to Groundwater Wells (PG). By assigning relative weights to each of these factors through expert judgment and a pairwise comparison matrix, the study produced susceptibility maps that highlight areas at greatest risk.

The results, depicted in the sinkhole susceptibility hazard zonation maps, show that 31% of the study area falls within the high hazard zone, while 10% is classified as very high hazard. These high-risk zones are predominantly located in the North West part of Kuala Lumpur, an area characterized by Kuala Lumpur Limestone Formation bedrock geology, consisting mainly of limestone/marble and acid intrusive lithology. This geological setting, combined with high levels of groundwater level decline, makes these areas particularly prone to sinkhole development.

GIS and AHP Integration

The integration of GIS and AHP in this study allowed for a systematic and spatially explicit assessment of the factors contributing to sinkhole formation. AHP, in particular, facilitated the weighting of different factors, enabling the researchers to rank the susceptibility of different areas accurately. The susceptibility maps generated from this model provide valuable insights into the spatial distribution of sinkhole hazards, helping urban planners and decision-makers prioritize areas for monitoring and mitigation efforts.

Validation and Model Accuracy

Rosdi et al. (2017) validated their model using a dataset of 33 previous sinkhole events. The validation results were promising, with 64% of the sinkhole events falling within the high hazard zones and 21% within the very high hazard zones. This strong correlation between the model’s predictions and actual sinkhole occurrences demonstrates the effectiveness of the AHP approach in predicting sinkhole hazards.

Limitations and Future Research

Despite the success of the SHM, the study acknowledges several limitations and suggests avenues for future research. One key limitation is the reliance on the AHP technique, which, while effective, may not capture the full complexity of the factors influencing sinkhole formation. The study recommends exploring alternative multi-criteria decision-making techniques, such as Fuzzy AHP, Weight of Evidence (WoE), and other methods that could potentially improve the accuracy of sinkhole susceptibility models.

Another limitation is related to data acquisition, particularly regarding geological and hydrological data. The study suggests that high-resolution satellite imagery could be used to update land use and land cover data, providing a more accurate and timely assessment of sinkhole risk. Additionally, the study highlights the importance of understanding the triggering effects of sinkholes, such as heavy rainfall and excessive groundwater extraction, which could be incorporated into future models.

Finally, the study recommends the computation of the magnitude and frequency relationship of sinkholes as a valuable technique for predicting the likelihood of future sinkhole occurrences. By analyzing the size and frequency of past sinkholes, researchers could better estimate the risk of future events, providing a more comprehensive tool for risk assessment and urban planning.

Conclusion

The study by Rosdi et al. (2017) represents a significant contribution to the understanding of sinkhole susceptibility in Kuala Lumpur and Ampang Jaya. The integration of GIS and AHP allowed for a detailed and spatially explicit analysis of the factors contributing to sinkhole formation, resulting in highly accurate susceptibility maps. However, the study also highlights the need for further research to refine these models and improve the accuracy of sinkhole risk assessments. By exploring alternative techniques and addressing the limitations identified, future studies could provide even more reliable tools for predicting and mitigating sinkhole hazards in urban areas. This ongoing research is crucial for safeguarding urban infrastructure and protecting the lives of those living in sinkhole-prone regions.

References

Rosdi, M. A. H. M., Othman, A. N., Zubir, M. A. M., Latif, Z. A., & Yusoff, Z. M. (2017). Sinkhole susceptibility hazard zones using GIS and analytical hierarchical process (AHP): A case study of Kuala Lumpur and Ampang Jaya. International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLII-4/W5, 145–151. https://doi.org/10.5194/isprs-archives-XLII-4-W5-145-2017

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Chemical Leak at Idemitsu Plant in Pasir Gudang, Johor – Safety Measures and Hazards

Source: Social Media

By Shahabuddin Amerudin

Incident Alert: Chemical Leak at Idemitsu Plant in Pasir Gudang, Johor – Safety Measures and Hazards

Introduction

A recent chemical leak incident at the Idemitsu (M) Sdn Bhd plant in Pasir Gudang, Johor, Malaysia, has raised concerns about safety and potential hazards. This article provides a comprehensive overview of the incident, details about the hazardous chemical involved, its distribution, and essential safety precautions for the local community.

Incident Details

On August 23, 2023, at approximately 5:21:54 PM, an emergency call reporting a chemical leak was received by the State Operations Center (PGO) in Johor. The incident occurred at the Idemitsu plant, located at Plo 408, Jalan Pekeliling, Pasir Gudang, Johor. An immediate response involving emergency personnel and specialized units was initiated.

The Hazardous Chemical: Styrene Monomer (UN Number 2055)

Styrene Monomer is the chemical responsible for the leak. It is a volatile organic compound (VOC) and is commonly used in the production of plastics, resins, and other materials. However, it can pose potential health and environmental risks under certain conditions.

Hazards of Styrene Monomer

Styrene Monomer can be hazardous when released into the environment, particularly in concentrated forms. Some of the risks associated with exposure include:

  1. Health Effects: Inhalation of styrene vapor can lead to irritation of the eyes, nose, throat, and respiratory tract. Prolonged or high-level exposure can cause dizziness, headache, and in some cases, central nervous system effects.
  2. Carcinogenic Concerns: There have been concerns about the potential carcinogenicity of styrene. Long-term occupational exposure to high concentrations of styrene vapor has been associated with an increased risk of certain cancers, although the evidence is not definitive.
  3. Environmental Impact: Styrene is considered a volatile organic compound (VOC) and can contribute to air pollution. It can also potentially contaminate soil and water bodies if not managed properly.

Distribution of Styrene Vapor

The distribution of styrene vapor during a leak depends on several factors:

  1. Wind Conditions: Wind speed and direction play a significant role in how far and in which direction the vapor disperses. Higher wind speeds can carry the vapor over longer distances.
  2. Ventilation: Adequate ventilation can help disperse the vapor more quickly, reducing the potential for vapor buildup in enclosed spaces.
  3. Terrain and Obstacles: Physical features such as buildings, hills, and valleys can impact the direction and distance of vapor dispersion.

Safety Precautions

To ensure the safety of the community:

  1. Stay Informed: Rely on official updates from authorities and avoid spreading unverified information.
  2. Avoid the Area: If you are not directly involved in response efforts, stay away from the vicinity of the incident.
  3. Comply with Authorities: Follow instructions from emergency personnel and cooperate with their directives.
  4. Stay Indoors: If near the incident site and indoors, remain indoors, close windows, and seal gaps to minimize exposure.

Conclusion

The chemical leak incident involving Styrene Monomer at the Idemitsu plant in Pasir Gudang underscores the importance of prompt response, community cooperation, and safety precautions. Understanding the hazards associated with the chemical and taking necessary precautions can help mitigate potential risks and ensure the well-being of both residents and the environment.

Suggestion for Citation:
Amerudin, S. (2023). Chemical Leak at Idemitsu Plant in Pasir Gudang, Johor – Safety Measures and Hazards. [Online] Available at: https://people.utm.my/shahabuddin/?p=6764 (Accessed: 24 August 2023).
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Hazard, Vulnerability, and Risk Maps

By Shahabuddin Amerudin

Hazard, vulnerability, and risk maps are essential tools used in disaster management and emergency response. These maps are used to identify and understand the potential threats and vulnerabilities of a given area and help decision-makers to develop strategies and plans for reducing risk and building resilience. In this article, we will discuss in detail the differences between hazard, vulnerability, and risk maps and their importance in disaster management.

Hazard Maps

Hazard maps are used to identify and visualize the potential hazards that can occur in a given area. A hazard is defined as a natural or human-induced event that has the potential to cause harm to people, property, and the environment. Examples of hazards include earthquakes, floods, landslides, hurricanes, and wildfires. Hazard maps are developed using various data sources, including historical data, remote sensing data, and ground surveys. The maps can be produced using GIS technology, which allows for the analysis and visualization of hazard data. Hazard maps are important for identifying high-risk areas and developing mitigation strategies.

Examples:

Vulnerability Maps

Vulnerability maps are used to identify the susceptibility of a given area to the potential hazards. Vulnerability is defined as the degree to which a community, system, or infrastructure is susceptible to harm from a particular hazard. Vulnerability maps take into account factors such as population density, infrastructure, socio-economic status, and environmental conditions. Vulnerability maps are important for identifying areas that are most vulnerable to hazards and developing strategies to reduce vulnerability.

Examples:

Risk Maps

Risk maps are used to identify and assess the potential risks associated with a given hazard. Risk is defined as the probability of an event occurring and the magnitude of its consequences. Risk maps combine hazard and vulnerability data to create a comprehensive understanding of the potential risks in a given area. Risk maps are important for identifying the areas with the highest risk and developing strategies to reduce risk and build resilience.

Examples:

  • The European Flood Awareness System (EFAS) provides a risk map of potential flood areas in Europe, showing the likelihood of flooding and the potential consequences. https://www.efas.eu/mapviewer/
  • The World Risk Index, developed by the UN University Institute for Environment and Human Security, shows the risk of disasters based on social, economic, and environmental factors in different countries. https://www.worldriskindex.org/

Conclusion

Hazard, vulnerability, and risk maps are essential tools in disaster management and emergency response. Each map provides a different perspective on the potential threats and vulnerabilities of a given area. Hazard maps identify the potential hazards, vulnerability maps identify the susceptibility of the area to the potential hazards, and risk maps combine hazard and vulnerability data to assess the potential risks. The maps can be produced using various data sources and GIS technology. The maps are important for identifying high-risk areas and developing strategies to reduce vulnerability and build resilience.

Suggestion for Citation:
Amerudin, S. (2023). Hazard, Vulnerability, and Risk Maps. [Online] Available at: https://people.utm.my/shahabuddin/?p=6213 (Accessed: 31 March 2023).
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Advancements and Challenges in Hazard and Risk Mapping

By Shahabuddin Amerudin

Introduction

Hazard and risk mapping has become an increasingly important tool in disaster management, providing decision-makers with critical information about potential hazards and risks in their communities. These maps help to identify areas that are most vulnerable to natural disasters, and to develop effective strategies for mitigation and response.

The history of hazard and risk mapping dates back to the early 20th century, when scientists began to study the impact of natural disasters on communities. Over time, the field has evolved to incorporate new technologies and data sources, as well as a greater emphasis on social and economic factors that contribute to vulnerability.

Today, there are many types of hazard and risk maps available, each with their own unique benefits and limitations. Some of the most common types include flood maps, earthquake maps, wildfire maps, and hurricane maps. These maps can be used to identify areas that are most at risk for a particular hazard, and to develop mitigation and response strategies tailored to the specific needs of each community.

In recent years, there has been a growing emphasis on developing more comprehensive and inclusive hazard and risk maps. This includes maps that incorporate social and economic factors, such as poverty, race, and access to resources, which can contribute to vulnerability during disasters. There are also emerging types of maps, such as dynamic risk maps, multi-hazard maps, social vulnerability maps, and participatory mapping, which aim to provide more nuanced and detailed information about hazards and risks.

Advancements in Hazard and Risk Mapping

Hazard and risk mapping has come a long way since its inception, with significant advancements in technology, data collection, modeling, and analysis. In recent years, there has been a growing emphasis on incorporating social and economic factors into hazard and risk maps, as well as the development of emerging types of maps that provide more nuanced and detailed information about hazards and risks.

One of the key advancements in hazard and risk mapping is the use of advanced technology and tools for data collection, modeling, and analysis. Geographic Information Systems (GIS) have become increasingly important in the creation of hazard and risk maps, allowing for the integration of a wide range of data sources, including satellite imagery, aerial photographs, and ground-based sensors. Other technologies, such as LiDAR, remote sensing, and machine learning, have also been used to improve the accuracy and resolution of hazard and risk maps.

Another important advancement in hazard and risk mapping is the incorporation of social and economic factors into these maps. While early hazard and risk maps focused primarily on physical factors, such as topography and land use, there is now a growing recognition of the importance of social and economic factors, such as poverty, race, and access to resources. Incorporating these factors into hazard and risk maps can provide decision-makers with a more comprehensive and inclusive view of vulnerability, and help to identify areas that are most at risk during disasters.

There are also emerging types of maps that are contributing to more comprehensive and inclusive views of hazards and risks. Dynamic risk maps, for example, provide real-time information about changing hazards and risks, such as wildfires or floods, allowing for more effective response and mitigation efforts. Multi-hazard maps combine information about multiple hazards, such as earthquakes and tsunamis, to provide a more comprehensive view of risk. Social vulnerability maps highlight areas that are most vulnerable to disasters based on factors such as income, race, and access to resources. Participatory mapping involves engaging local communities in the mapping process, allowing them to contribute their own knowledge and perspectives on hazards and risks.

Overall, the advancements in hazard and risk mapping are helping to build more resilient communities and reduce the impact of natural disasters. By incorporating social and economic factors into these maps, and developing new types of maps that provide more comprehensive and inclusive views of hazards and risks, decision-makers can make more informed decisions and develop more effective mitigation and response strategies.

Challenges in Hazard and Risk Mapping

Hazard and risk mapping is a critical tool in disaster management, providing decision-makers with critical information to assess and mitigate potential risks. However, there are several challenges associated with hazard and risk mapping that need to be addressed to improve their effectiveness.

One of the key challenges is data quality and availability. Hazard and risk mapping relies on accurate and up-to-date data from a range of sources, including satellite imagery, remote sensing, and ground-based sensors. However, there are often gaps in data availability, particularly in developing countries, which can lead to inaccurate or incomplete hazard and risk maps. Additionally, the quality of data can vary widely, making it difficult to compare and integrate data from different sources.

Another challenge is modeling accuracy. Hazard and risk maps rely on complex modeling techniques to assess the likelihood and impact of potential hazards. However, these models are often based on simplified assumptions and can be impacted by uncertainties in the data. This can lead to inaccurate or incomplete hazard and risk maps that do not reflect the true risks to communities.

Effective communication and engagement with communities is also a challenge in hazard and risk mapping. While hazard and risk maps can provide valuable information to decision-makers, they are often complex and difficult for the public to understand. This can lead to a lack of trust in the maps and a failure to take appropriate action to mitigate risks. Additionally, there can be cultural or linguistic barriers that prevent effective communication and engagement with some communities.

To address these challenges, ongoing efforts are needed to improve hazard and risk mapping. Data sharing initiatives can help to improve data quality and availability by making data more accessible to a wider range of users. Better modeling and analysis tools, including advanced technologies such as machine learning, can help to improve the accuracy of hazard and risk maps. Improved communication and engagement strategies, such as the use of participatory mapping and community-based approaches, can help to ensure that hazard and risk maps are understood and trusted by the communities they are designed to serve.

Conclusion

Hazard and risk mapping has come a long way since its inception, evolving in response to advances in technology, data collection, modeling, and analysis. While traditional hazard and risk maps are still valuable tools in disaster management, emerging types of maps, such as dynamic risk maps, multi-hazard maps, social vulnerability maps, and participatory mapping, are contributing to more comprehensive and inclusive views of hazards and risks.

However, despite the progress made in hazard and risk mapping, there are still several challenges that need to be addressed. Issues related to data quality and availability, modeling accuracy, and communication and engagement with communities continue to pose significant obstacles. Addressing these challenges will require ongoing efforts to improve hazard and risk mapping, including data sharing initiatives, better modeling and analysis tools, and improved communication and engagement strategies.

In conclusion, hazard and risk mapping is a crucial component of disaster management, providing decision-makers with the information they need to prepare for, respond to, and recover from disasters. As such, it is essential that policymakers, researchers, and practitioners continue to advance hazard and risk mapping to better support decision-making and disaster resilience. By working together, we can create more accurate, reliable, and accessible hazard and risk maps that can help build more resilient and sustainable communities.

Suggestion for Citation:
Amerudin, S. (2023). Advancements and Challenges in Hazard and Risk Mapping. [Online] Available at: https://people.utm.my/shahabuddin/?p=6208 (Accessed: 31 March 2023).