Richard Teeuw

Framing volcanic risk communication within disaster risk reduction: finding ways for the social and physical sciences to work together

Abstract Sixteen years have passed since the last global volcanic event and more than 25 since a volcanic catastrophe that killed tens of thousands. In this time, volcanology has seen major advances in understanding, modelling and predicting volcanic hazards and, recently, an interest in techniques for reducing and mitigating volcanic risk. This paper provides a synthesis of literature relating to this last aspect, specifically the communication of volcanic risk, with a view to highlighting areas of future research into encouraging risk-reducing behaviour. Evidence suggests that the current ‘multidisciplinary’ approach within physical science needs a broader scope to include sociological knowledge and techniques. Key areas where this approach might be applied are: (1) the understanding of the incentives that make governments and communities act to reduce volcanic risk; (2) improving the communication of volcanic uncertainties in volcanic emergency management and long-term planning and development. To be successful, volcanic risk reduction programmes will need to be placed within the context of other other risk-related phenomena (e.g. other natural hazards, climate change) and aim to develop an all-risks reduction culture. We suggest that the greatest potential for achieving these two aims comes from deliberative inclusive processes and geographic information systems.

Estimation of error in bankfull width comparisons from temporally sequenced raw and corrected aerial photographs

This study investigates the propagation of error through image-to-image comparison of 285 river bankfull width measurements of the Afon Trannon, mid-Wales. Bankfull width is quantified from both aerial photographs analysed as rectified images in ERDAS Imagine OrthoMax and raw images in Paintshop Pro. A method for the robust estimation of bankfull width measurement error through temporal sequences of scanned aerial photographs is presented and the improvement in accuracy achieved using rectified imagery is quantified. Results from this study are placed in the context of previously published rates of bankfull width change, from a wide range of river scales, and the bankfull change rates for robust medium-term analysis using approximately 1:10,000 historical aerial photography are identified.

Advances in the remote sensing of volcanic activity and hazards, with special consideration to applications in developing countries

Applications of remote sensing for studies of volcanic activity and hazards have developed rapidly in the past 40 years. This has facilitated the observation of volcanic processes, such as ground deformation and thermal emission changes, lava flows, eruption clouds, ash and gas emissions, as well as mapping of volcanic structures and hazardous terrain, even for volcanoes in remote regions. Advances in the remote sensing of volcanoes, from ground‐based sensors to sensors onboard airborne and spaceborne platforms, are reviewed. A key point made in this review is that volcanic remote sensing could have a much broader impact if the techniques and data were readily available to scientists studying/monitoring potentially hazardous volcanoes in developing countries. Perspectives on particular needs, with regard to sensor types, data availability and training, required to take volcanic remote sensing further in coming years are highlighted.

Free software: A review, in the context of disaster management

This article examines the nature of freely available geospatial software and information systems in the context of disaster management. The use of geospatial data is crucial to effective disaster management, from preparedness to response and recovery. However, to make efficient use of available data and information – before, during and after a disaster – reliable software is required. The software applications examined in this paper range from Geographical Information Systems, to the processing of remotely sensed images, crowd-source mapping, web applications and content management systems. Trends and challenges are considered, and guidelines are given, to foster and encourage the provision of information by Freeware and Open Source Software. Free geoinformatics can help to optimize the limited financial, technological and manpower resources that many organisations face, providing a sustainable input to analytical activities.

Mapping hazardous terrain using remote sensing

The dangers that we face from geohazards appear to be getting worse, especially with the impact of increasing population and global climate change. This collection of papers illustrates how remote sensing technologies - measuring, mapping and monitoring the Earth’s surface from aircraft or satellites - can help us to rapidly detect and better manage geohazards. The hazardous terrains examined include areas of landslides, flooding, erosion, contaminated land, shrink-swell clays, subsidence, seismic activity and volcanic landforms. Key aspects of remote sensing are introduced, making this a book that can easily be read by those who are unfamiliar with remote sensing. The featured remote sensing systems include aerial photography and photogrammetry, thermal scanning, hyperspectral sensors, airborne laser altimetry (LiDAR), radar interferometry and multispectral satellites (Landsat, ASTER). Related technologies and methodologies, such as the processing of Digital Elevation Models and data analysis using Geographical Information Systems, are also discussed.

Free or low-cost geoinformatics for disaster management: Uses and availability issues

The disaster management applications of geographical information systems and remote sensing are examined relative to the disaster cycle, in pre-disaster, crisis and post-disaster contexts. We focus on the uses and limitations of free or low-cost data and software. A wide range of geospatial datasets are currently freely available, from digital elevation models (DEMs) and thematic digital maps, to multispectral satellite imagery and virtual globes, such as Bing Maps. Maps of hazardous terrain and vulnerable features can be derived from sets of satellite data such as shuttle radar topography mission DEMs and Landsat imagery. The derived maps are particularly useful for district scale (1:25 to 1:100 K) disaster management in low-income countries. Detailed maps (i.e. better than 1:25 K scale) of hazardous terrain and vulnerable features generally require expensive high-resolution satellite imagery or aerial photography. Although the Internet allows the distribution of free or low-cost geospatial data, software and training materials, there are still some countries with limited Internet access. Data integration, spatial/temporal analysis and map production are also limited by the frequently high price of geoinformatic software, making it a priority to develop suitable Free and Open-Source Software.

Large Coastal Landslides and Tsunami Hazard in the Caribbean

With nine volcanic peaks in a 750-square-kilometer area, Dominica, in the Lesser Antilles volcanic arc (Figure 1), has one of the highest concentrations of potentially active volcanoes in the world [Lindsay et al., 2005]. Dominica is very hilly, and there have been numerous landslides, particularly on the islands wetter eastern and northern coasts. Lindsay et al. [2005] consider the likelihood of gravitational collapses on the flanks of Dominicas volcanoes to be “low but not negligible.” However, many factors make Dominica particularly prone to large landslides (>1 million tons): (1) extensive zones of weakened rock, due to hydrothermal alteration and/or intense tropical weathering; (2) oversteepened slopes associated with tectonic uplift and erosion of volcanic edifice foot slopes; (3) large amounts of rainfall on the volcanic uplands, especially during the hurricane season (June–October), with annual averages of up to approximately 6000 millimeters; and (4) occasional severe seismic activity, e.g., a magnitude 7.3 earthquake on 29 November 2007, with its epicenter between Dominica and Martinique, and another of magnitude 6.2 on 21 November 2004, with its epicenter between Dominica and Guadeloupe.

Using geoinformatics and geomorphometrics to quantify the geodiversity of Crete, Greece

The geodiversity of Crete is quantified in this study, based on the classification of geomorphometric, geological and climatic factors. A number of geomorphometric variables, extracted from the ASTER Global Digital Elevation Model (ASTER G-DEM) in conjunction with geological and climatic information, are evaluated through various algorithms incorporated into Geographical Information System (GIS) software’s. The derived geoinformatic data sets are then analyzed to produce the geodiversity of Crete. The geodiversity map is used to quantify the geodiversity, by calculating landscape diversity and other spatial pattern indices. Those indices are evaluating the richness, evenness, fragmentation and shape of the landscape patch types. The outcome of this study has highlighted that western Crete is characterized by complex geodiversity with more irregular, elongated and fragmented landscape patterns relative to the eastern part of the island. The geodiversity indices provide insights into the processes shaping landscapes, particularly the “battle” between neotectonic landscape deformation and erosion/deposition. The methodology presented can be useful for decision makers when evaluating a regions geological heritage, planning the management of natural resources, or designating areas for conservation.

Quantitative accuracy assessment of contextually filtered classified images

Original article can be found at: http://www.informaworld.com/smpp/title~content=t713722504~db=all Copyright Informa / Taylor and Francis [The full text of this article is not available in the UHRA]

Dating of Quaternary Sediments from Western Borneo, Using Optically Stimulated Luminescence

Optically Stimulated Luminescence (OSL) dates from five sites in western Kalimantan are compared with 14C and thermo-luminescence dates from other sediments in the region. There is now strong evidence that the Old Alluvium of Peninsular Malaysia is of late Pleistocene age and that it can be correlated with the White Sand Complexes of western Borneo. This contrasts with the late Pliocene to mid Pleistocene ages for Old Alluvium, based primarily on stratigraphic deductions, put forward by geoscientists examining the regional tin deposits. This study shows that the upper parts, at least, of the western Borneo White Sand Complexes were deposited mid-way through the last glaciation (76 ka), with extensive terminal Pleistocene re-deposition (11.2-9.8 ka) and at least two gully erosion events during the Holocene (5.8-3.8 ka and 0.48 ka).