Tsunami

December 2004 Tsunami disaster is natural disasters which is caused by purely natural phenomena and bring damage in huge scale to 6 provinces along the Andaman Sea, southern of Thailand namely Ranong, Phangnga, Phuket, Krabi, Trang, and Satun. The information gathering and applying geo-informatics technology have been used in phases of mitigation and recovery. Such an affected area interpolation can be executed successfully in multi-spatial, multi-temporal and multi-spectral characteristics. An affected and damage area as obtained from the interpolation of high resolution IKONOS and QuickBird are the main information sources. We found that main types of damage are coastalshoreline erosion and damage to constructions such as buildings, roadnetwork, bridges, shorelines, acquacultural cages, fishing vessels, and the environment as well.

Tsunami occurred on December 26th, 2004 and caused heavy losses of lives and properties along the western coast of Thailand, especially in the six provinces along the Andaman Sea. In order to prepare for such unpredictable natural disaster, Tsunami Warning System Committee agreed to establish tsunami warning towers in the six provinces along the Andaman coastline as the first priority. GISTDA utilized LANDSAT and IKONOS satellite images along with GIS to locate the most suitable sites for tower installation. Factors that were taken into consideration in locating the sites include the risk of the area for tsunami, effectiveness of tower working range and the towers must not block the good view of scenery. The Committee then selected the sites and has established three tsunami-warning towers in Phuket, which have been in operation since April 2005. Each is located 3 km apart from each other and can broadcast within 1.5 km range. In summary, satellite images are extremely…

A study of tsunami impact was undertaken along India’s Karaikal coast from Poovam in Karaikalto Nagore, Nagapatinam. An integrated approach was adopted for the preparation of thematic maps on land use, land cover and coastal geomorphology using multispectral remote sensing data. RTK GPS instruments were used for the collection of topographic data with contour intervals of 0.5m. The GIStool was used to incorporate the elevation data, the extent of tsunami inundation and the thematic maps derived from remote sensing data. The present study highlights the most vulnerable areas of tsunami inundation and provides demarcations of suitable sites for rehabilitation.

Tsunami impact study has been undertaken along Chennai coast starting from Pulicat to Kovalam. The study area Chennai coast is mainly devoted to prepare large scale action plan maps on tsunami inundation incorporating landuse details derived from satellite data along with cadastral data using a GIS tool. Under tsunami inundation mapping along Chennai coast an integrated approach was adopted to prepare thematic maps on land use/land cover and coastal geomorphology using multispectral remote sensing data. The RTK dGPS instruments are used to collect elevation contour data at 0.5m intervals for the Chennai coast. The GIS tool has been used to incorporate the elevation data, tsunami inundation markings obtained immediately after tsunami and thematic maps derived from remote sensing data. The outcome of this study provides an important clue on variations in tsunami inundation along Chennai coast, which is mainly controlled by local geomorphologic set-up, coastal zone…

Extreme natural events, like e.g. tsunamis or earthquakes, regularly lead to catastrophes with dramatic consequences. In recent years natural disasters caused hundreds of thousands of deaths, destruction of infrastructure, disruption of economic activity and loss of billions of dollars worth of property and thus revealed considerable deficits hindering their effective management: Needs for stakeholders, decision-makers as well as for persons concerned include systematic risk identification and evaluation, a way to assess countermeasures, awareness raising and decision support systems to be employed before, during and after crisis situations. The overall goal of this study focuses on interdisciplinary integration of various scientific disciplines to contribute to a tsunami early warning information system. In comparison to most studies our focus is on high-end geometric and thematic analysis to meet the…

Tsunamis are an ever-present threat to lives, infrastructure, and property along the coasts of the world's oceans. Recent tsunamis deeply impacted the shores of Indonesia, calling for early warning systems as well as risk and vulnerability assessment as basis for mitigation strategies, evacuation planning and rehabilitation organization. Research on tsunamis focuses on tsunamis generation, wave propagation, inundation and interactions with structures. This study is focusing on the latter, using the capabilities of high resolution satellite data to assess tsunami vulnerability in urban areas. Based on an object-oriented land-cover classification the physical urban morphology is structured using parameter like built-up density, function, building sizes or location. The distribution of a total population following the structural characteristics of an urban morphology is determined by assuming a dependency between numerical and spatial units. Using the derived physical and…

In the aftermath of the Indian ocean tsunami, the media indicated that the clearing of coastal mangrove ecosystems for tourism and aquaculture may have have exacerbated infrastructure damage and human loss. This paper documents the use of moderate- and high resolution remote sensing imagery to furnish a multi-disciplinary international project team with data to begin scientifically investigating this assertion for the coast of Thailand. High resolution imagery in turn focused on selected study sites within the provinces of Ranong and Phang Nga. Of the multiple analyses that were conducted, this paper first documents the use of an historical sequence of Landsat 5 imagery spanning the past two decades to map changes in mangrove extents as an indicator for pre-tsunami environmental degradation. It goes on to describe the assessment of damage to coastal communities using high-resolution Quickbird and IKONOS imagery collected before and soon after the event. Following a…

Remote sensing has emerged as a powerful tool for mitigation planning and post-crisis assessment in various natural hazards. The development of advanced remote sensing technologies has improved mapping capabilities and expanded areas of application. The most significant improvement is the commercialization of very high spatial resolution satellite data. Here, remote sensing data and methods were used to support the development of tsunami inundation maps for the City of Rhodes, Greece, as well as to help ground truthing modeling results. Information about the topography was derived using both satellite and aerial images. ASTER (Advanced Spaceborn Thermal Emission and Reflection Radiometer) stereo images were used to provide a Digital Elevation Model (DEM) for the whole island, whereas aerial imagery was used to derive a high resolution DEM for the Northern part where the city of Rhodes is located. These DEMs were used to orthorectify multispectral ASTER and Ikonos…

Based on LANDSAT ETM and Digital Elevation Model (DEM) data derived by the Shuttle Radar Topography Mission (SRTM, 2000) of the coastal areas of Northern Venezuela were investigated in order to detect traces of earlier tsunami events. Digital image processing methods used to enhance LANDSAT ETM imageries and to produce morphometric maps (such as hillshade, slope, minimum and maximum curvature maps) based on the SRTM DEM data contribute to the detection of morphologic traces that might be related to catastrophic tsunami events. These maps combined with various geodata such as seismotectonic data in a GIS environment allow the delineation of coastal regions with potential tsunami risk. The LANDSAT ETM imageries merged with digitally processed and enhanced SRTM data clearly indicate areas that might be prone by flooding in case of catastrophic tsunami events.

Based on LANDSAT ETM and Digital Elevation Model (DEM) data derived bu the Shuttle Radar Topography Mission (SRTM) of the coastal areas of Greece were investigated in order to detect traces of earlier tsunami events. Digital image processing methods used to produce hillshade, slope, minimum and maximum curvature maps based on the SRTM DEM data contribute to the detection of morphologic traces that might be related to catastrophic tsunami events. These maps combined with LANDSAT ETM and seismotectonic data in a GIS environment allow the delineation of coastal regions with potential tsunami risk. The evaluations of Landsat ETM imageries merged with digitally processed and enhanced SRTM data clearly show areas that must have been flooded in earlier times. In some cases morphologic traces of waves as curvilinear scarps open to the sea-side are clearly visible.