SEISMIC MICROZONATION FOR BANDA ACEH CITY PLANNING

Geographic information systems (GIS) technology enables sophisticated, numerical-based mapping of earthquake hazards, including liquefaction and landslide susceptibility, on a regional basis for pipeline systems. Existing earthquake hazard mapping was integrated with interpretation of topographic, geologic, hydrologic, and geotechnical data to update an earthquake hazard database for Pacific Gas & Electric Company’s California Gas Transmission (CGT), as part of the CGT Pipeline System Integrity program. The regionally consistent, map-based database covering CGT’s pipeline system in northern California allows for modeling of possible pipeline impacts from moderate to large earthquakes. GIS-based modeling that incorporates the hazard mapping is a powerful tool for planning and emergency response purposes. Specifically, near real-time models of possible pipeline damage locations can be derived from internet-based groundshaking records (USGS ShakeMap) produced after earthquakes. Scenario-based models of earthquake impacts from possible earthquakes can be used for planning purposes.

The southern part of Java Island is susceptible to tsunamis as its role as a subduction zone between Indo-Australian and Eurasian plates. On July 17, 2006, a tsunami struck Java's south coast triggered by an earthquake and affected more than 300 km of shoreline, as well as claimed more than 730 casualties. It is important to assess the risk in the southern part of Java. This research aims to analyze tsunami risk assessments on public facilities in the southern part of Bantul Regency, Yogyakarta. The Tsunami hazard map was created by using tsunami modeling from BMKG. Public facilities footprint such as health facilities, religious facilities and school were derived from data provided by Open Street Map (OSM). The Papathoma Tsunami Vulnerability Assessment (PTVA) model, specifically developed to estimate the relative vulnerability of buildings to tsunami hazards, is used to generate a building vulnerability map. A geographic information system (GIS) was utilized to calculate and visualize the hazard, vulnerability, and risk map. A total of 394 buildings were analyzed with the results that public facilities in three sub-districts, namely Srandakan, Sanden and Kretek, had varying levels of building vulnerability ranging from minor, moderate, average and high with RVI values ranging from 1.5 to 3.4. Additionally, tsunami risk assessment of public facilities indicates that buildings within Bantul Regency are categorized as having very high, high, moderate, or low levels of building risk.

This study reviewed problems of tsunami hazard map from the view point of residents and municipalities, and pointed out an importance of the linkage between a tsunami forecast and a tsunami hazard map. And, the method of making tsunami hazard map linked the JMA tsunami quantitative information system was proposed. About 4000 tsunami propagation tsunami were calculated for Owase-city, and the fault parameters were categorized into 7 ranks of tsunami forecast height, then the maximum inundation area at each categories were evaluated by the run-up calculations. This hazard map could help municipalities to rapidly issue an evacuation warning, to reduce a failure of evacuation warning, and to extend the warning area in case of large tsunami.

Tsunami inundation mapping is the first step in the development of effective evacuation plans for communities at risk. These maps also provide bases for land use planners in communities to reduce risk by locating critical facilities out of the potential tsunami flood plain. The Makran subduction zone, located off the Indian Ocean coasts of Iran and Pakistan, is an important tsunamigenic zone for the region. On the 27th November, 1945, it was the site of a major earthquake with a moment magnitude of 8.1 and killed about 4,000 people. This event is a proof that Makran coastal areas are unsafe since the tsunami is quite probable. The objective of this study was providing tsunami inundation and hazard maps in Chabahar bay which is located in South East of Iran and the northern coast of Oman Sea. Three different source magnitude scenarios along Makran subduction zone are considered and for each scenario, numerical modeling of tsunami propagation is performed using MIKE 21 FM numerical software. Because the Makran subduction zone is very close to the Chabahar bay, unstructured triangular mesh with a higher level of refinement closer to the area of interest was used so that the tsunami was not numerically dissipated. After analyzing the data obtained from the results, inundation maps were produced, and by combining these maps, tsunami hazard map was provided for the bay. Tsunami wave amplification has been observed mainly in the outer coasts of the bay where the uplifted rocky shore experience up to 18 m wave height. Chabahar bay omega form and two eastern and western headlands cause a considerable depreciation in tsunami wave. Longer distance of coasts within the bay is another reason of tsunami depreciation inside the bay. Based on the generated inundation and hazard maps, two flood zones are specified. The first zone associated with no inundation or low inundation on cliffy shores, and the second zone would experience extensive inundation on the coast of kenarak areas, areas with sandy beaches and gentle slope.

Seismic risk in the form of impending disaster has been seen from past records that moderate-to-large earthquakes have caused the loss of life and property in all parts of Nepal. Despite the availability of new data, and methodological improvements, the available seismic hazard map of Nepal is about two decades old. So an updated seismic hazard model at the country level is imperative and logical. The seismic hazard and risk model constitute important tools for framing public policies toward land-use planning, building regulations, insurance, and emergency preparedness. In fact, the reliable estimation of seismic hazard and risk eventually minimizes social and economic disruption caused by earthquakes. In this frame of reference, the seismic risk assessment at a country level is elementary in reducing potential losses stemming from future earthquakes. Thus, this study investigates structural vulnerability, seismic risk, and the resulting possible economic losses owing to future earthquakes in Nepal. To this end, seismic risk assessment in Nepal is done using an existing probabilistic seismic hazard, a newly developed structural vulnerability, and recently released exposure data. The OpenQuake-engine, the open-source platform for seismic hazard and risk assessment from the Global Earthquake Model initiative, was used to calculate the seismic hazard and risk in Nepal. The seismic hazard and mean economic loss map were formulated for the 1, 2, 5, and 10 % probability of exceedance in 50 years. Finally, the distribution of building damage and corresponding economic losses due to the recurrence of the historical 1934 earthquake was presented in this study.

The creation of earthquake hazard maps requires various datasets with selected attenuation relations. Based on the selected attenuation relation, the calculation time varies from half an hour to a couple of days. The length of time needed to create an earthquake hazard map also depends on the resolution of the resulting map. The time gets longer as the resolution of the resulting earthquake hazard map gets higher. The basic form of an attenuation relation requires complex calculation algorithms including geospatial information related to the region of interest. Nowadays, next-generation attenuation (NGA) models are introduced to generate more realistic earthquake hazard maps. However, the more complex the attenuation relation is, the longer time will be required to create a hazard map. This paper offers a new method to create high-resolution earthquake hazard maps, faster than using traditional attenuation relation methods, by using an analytic hierarchy process of spatial multi-criteria decision analysis and geographic information systems. This method has been generated and tested for the city of Istanbul. The resulting maps are compared with the earthquake hazard maps created for the city of Istanbul by using the NGA model of Boore and Atkinson (in Boore–Atkinson NGA ground motion relations for the geometric mean horizontal component of peak and spectral ground motion parameters (trans: Engineering Co, University of California B). Pacific Earthquake Engineering Research Center 2007). A second output of this paper is a map of the elements at risk (EaR) for the population and buildings of Istanbul, and the introduction of a new approach of net elements at risk (NEaR).

This research was conducted with a view to updating the management of earthquakes through an exposure vulnerability and potential seismic risk assessment, along with its application in Sabah (a state in East Malaysia). A set of indicators and methodologies has been proposed in this study with the goal of evaluating the level of exposure vulnerability and potential risk of certain locations to earthquake events at the local district scale. This study specifically involves the development of exposure vulnerability indicators; the statistical analysis method to standardize multivariate data together with a weight calculation of indicator variables; and a mathematical combination of different indicators for the development of the index map using the spatial analysis function of Geographical Information System (GIS) tools. Then, the derived exposure vulnerability index (EVI) map is overlaid with the seismic hazard in determining the geographical location of the most vulnerable areas and their exposure to seismic hazard events. As a result, and based on the available data, the exposure vulnerability index map shows that most districts in Sabah are at relatively low and moderate levels of risk except for a few districts, with several major cities in Sabah, such as Kota Kinabalu, Penampang, Sandakan and Tawau municipality, being situated at a high or very high exposure index. The combination of EVI maps and hazard maps indicate the dominance of the two factors influencing the potential level of earthquake risk. Studies reveal most of the southwest and central parts of the region are not at risk, as both exposure and hazard factors are at a low level. The proposed approach depicts an instrument for identifying cost-effective risk reduction initiatives by providing a scientific method for regional risk planning and management strategies. This research represents the first attempt to evaluate Sabah’s vulnerability to this type of natural disaster by understanding the spatial relationship between exposure vulnerability and earthquake hazard, which undoubtedly could be improved in several aspects.

The goal of the multi-year seismic microzonation mapping project for Greater Vancouver, British Columbia, Canada, is to produce seismic hazard maps inclusive of local site effects, in particular seismic hazard specific to one-dimensional site response and three-dimensional Georgia sedimentary basin amplification, as well as liquefaction and landslide hazard potential. We explore the variability in key seismic site characterization measures most often used for seismic microzonation mapping to evaluate the impact on mapping and communication of seismic microzonation of Greater Vancouver. This study focuses on the comparison of seismic microzonation maps of Greater Vancouver based on up to three seismic site term parameters and their associated classification schemes: 1) the time-averaged shear-wave velocity (Vs) of the upper 30 m (Vs30) and associated Canadian National Building Code (NBC) site class; 2) Vs30-based site classification proposed for the updated Eurocode 8; 3) site period (T0) determined from microtremor site amplification spectra; and 4) a hybrid site classification based on T0 and the average Vs and thickness of soil. 810 Vs30 and 2,200 T0 values are determined to evaluate sub-regional differences in these important seismic site parameters in Greater Vancouver. We find that the seismic microzonation of Greater Vancouver depends on the chosen seismic site parameter (Vs30, T0, or a combination of parameters) and that classification schemes with greater class divisions are beneficial to communicating the great variability in seismic site conditions in Greater Vancouver. We recommend that either one hybrid classification map or two classification maps of Vs30 and T0 together are required for effective communication of the seismic microzonation of Greater Vancouver.

Flood hazard is one of the most common natural hazard in plain urban area. The location chosen for the study is Zhengzhou city, provincial capital, China. The model incorporates four factors: rainstorm with increased frequency and intensity, land subsidence, density of population, impermeable land surface, land use change. In this study, the coupling of geographical information system (GIS) and the analytical hierarchy process (AHP) were used, GIS analysis urban flood hazard vulnerability based on the underlying change and AHP was used in order to calculate the weighting values of each factor. A hazard map, based on the historical data in the past ten years, was obtained by spatial analysis technology. The hazard map was compared with the actual flood area, and good coincidence was found between them. The flood hazard assessment method presented here is meaningful for the local government to improve flood risk management and protecting environment.

European Directive 2007/60/EC only briefly mentions the problem of hazard arising due to groundwater flooding, and techniques for the mapping of hazard occuring due to rising groundwater have not yet been scientifically developed. The groundwater‐related threats that occur during floods may include concentrated leakage of groundwater behind levees, heave, or potential uplift of the topsoil layer at the protected area. The hazard corresponding to rising groundwater level depends on a number of factors related to the flood course, groundwater regime, geology, and topology of the protected area. The limit state approach is applied to the assessment and mapping of hazard induced by rising groundwater level in the area behind flood protection barriers, and the contributing factors are discussed, quantified, and incorporated into the limit state condition for topsoil layer uplift (UPL). An over‐design factor is expressed as a function of the spatial co‐ordinates (x, y). Data from geological and hydrogeological surveys and groundwater flow modelling are used to evaluate individual terms in the limit state condition. Uncertainties in the input data are expressed via partial factors. Data collection and their geographic information systems analysis completed with hydraulic modelling are crucial techniques in the hazard mapping of potential UPL during floods. The article includes a case study featuring a flood protection scheme for a shopping centre in the city of Brno, Czech Republic.

In this study, the flood hazard of Corum province (Turkey) was investigated using the Analytic Hierarchy Process (AHP), which is one of the most popular Multi-criteria Decision Analysis (MCDA) methods, based on Geographic Information System (GIS). As a result of the AHP process, Corum province was categorized into five flood hazard classes: very high, high, medium, low, and very low. It was determined that 3% of the total area is under a very high flood hazard, and 25% is considered a high flood hazard. To assess the validity of the flood hazard map, the results were compared with the historical flood inventory. Our hazard map was compatible with the historical flood inventory, and our hazard map can now be used to estimate the areas that are threatened by possible floods. When the existing structural measures are overlapped with the hazard map in Corum, it is understood that a large part of the structural measures carried out to date have focused on the areas of very high and high flood hazard in the flood hazard map. Future structural measures and detailed studies should now address other areas identified as under threat in the flood hazard map. Our results suggest that the hazard assessment based on MCDA is suitable for flood hazard mapping.

Ground movements constitute active processes that modify the disposition and morphology of the earth's surface. This work establishes a cartography procedure to obtain a ground movement risk map at a 1:50,000 scale. Such a map would be useful for establishing mitigation measures for land use planning and management in natural spaces, using Geographic Information Systems (GIS). A number of steps are taken to produce the map in GIS. First, a susceptibility map is created by considering passive or conditioning factors, which depend on the nature, structure and morphology of the ground. Second, a hazard map is created by considering active or trigger factors, which cause instabilities within hillsides and determine the magnitude and speed of their movements. Finally, the ground movements risk map is obtained by combining the susceptibility and hazard maps with risk and vulnerability map (degree of potential damage) and risk exposure map (estimate of damage, human casualty and economic loss). The resulting ground movements risk map shows very high risk at the foot of escarpments and abrupt reliefs where urban areas, fractures and/or roads are present. High risk prevails in the geomorphologic domains of fluvial incisions, where the slopes are high, as well as in areas with escarped hillsides. Medium-risk areas are distributed around the marked reliefs, forming zones of filling and slightly flat surfaces. Low-risk areas appear in topographically flat areas, since they are domains of terraces, pediments or degraded surfaces. Very scattered and less-extended areas present very low risk.

Overview of local site effects and seismic microzonation mapping in Metropolitan Vancouver, British Columbia, Canada

Throughout the course of human history, significant pressures have been in place to develop the coastline. Whether these pressures are a result of commercial and industrial needs or recreational preference, humans have always tended to settle at or near the waterfront. While obvious benefits can be reaped from this anthropogenic pattern, it also results in significant portions of the world's population subject to flood hazards. With the potential for these hazards to increase due to climate change, coastal zone managers and planners require tools to mitigate the risk to this population. One such tool is Geographic Information Systems (GIS). With GIS technology being at the forefront of Federal Emergency Management Agency's (FEMA) Map Modernization efforts, it has proven to be an effective tool in coastal hazard mitigation. The GIS technology is extensively used to evaluate land use and population change in the coastal areas which ultimately drives the coastal hazard mapping. The identification of risk requires analyzing large GIS data sets including topographic data (e.g. TIN {triangular irregular network} and GRID), orthophotography, land use data, and census population data. The GIS technology can effectively analyze these large data sets using the calculation algorithms built in to the GIS software such ArcGIS and present information that will guide decision makers. The 3D rendering capability of GIS software can be used to visualize various scenarios which aid in effective hazard identification and mitigation. The 3D GIS mapping and animation tools can also be applied to simulate various disaster scenarios that can ultimately aid planners in prevention of human and property loss during coastal disasters. In FEMA Region I, CDM, a FEMA study contractor and its partner OCC have been involved in numerous coastal hazard studies across New England. Together CDM and OCC have scoped total of six counties and have been involved in coastal engineering and mapping activities in more than 10 counties across New England. This paper will present methodologies to analyze various data sources and identify coastal flooding risks.

In flooding, dry land capable of residential, agricultural, and other economic activities is submerged by overflowing water. This causes loss of lives, properties, and destruction of infrastructure. This study applies remote sensing and GIS techniques to produce a flood vulnerability map of the Akure South metropolis. For this study, satellite image data (Landsat 8), location map of Akure South metropolis, SRTM DEM, rainfall data, soil data, and GPS coordinates; acquired during the field survey were integrated to map areas vulnerable to flooding. Using Pairwise Comparison, the various weights of factors constituting flood in the area were acquired. A weighted linear combination and analytical hierarchical process were used to produce the flood hazard and flood vulnerability map. ArcGIS Pro 2.7.3 software was used in spatial and attribute data acquisition, processing, and information presentation. The flood vulnerability results indicated that the very high vulnerability zone occupied 13.9% of the study area, while high vulnerability zone occupied 25.5%. Moderate vulnerability zone occupied 36.8% while low vulnerability zone occupied 23.8% of the study area. The study shows that, remote sensing and GIS can be effectively implemented to analyse and provide results on flood vulnerability required for prompt and effective decision-making on floods.