Volcanic Risk Assessment and Mapping in the Vesuvian Area Using GIS

This paper assesses the risk to people and property from lava flow hazard in the Vesuvian area of Italy using a Geographical Information System (GIS). The intense urbanisation and dense population near Mt. Vesuvius make the area very hazardous. Due to the large amount of available data, GIS is an essential tool to facilitate risk evaluation and constant monitoring of the zone. This analysis is based mainly on a lava flow hazard map of Mt. Vesuvius, determined from volcanic activity between 1631 and 1944. A land-use zonation map of the area was created in order to show areal distribution of the resources, built-up centres and population. For each of the 17 municipalities in the area, demographic and urban data were entered into the GIS database and linked to each appropriate geographic unit in order to create a set of reference maps at the 1:50 000 scale. The lava flow hazard map was overlain on the land use map, and spatial and numerical information of risk were extracted from the resulting maps.     

Contribution of Geographical Information Systems to the Management of Volcanic Crises

The incorporation of a set ofcomputer-based tools, such as Geographical InformationSystems and physical models, to the field of riskassessment, introduces a new perspective in thevolcanic risk maps production, increasing the analysisand modelling capabilities available through theapplication of conventional methodologies. Amethodology adapted to the requirements andcharacteristics of the new operating environment hasbeen applied at Tenerife island (Canary Islands,Spain) to carry out a study devoted to analyse thesuitability of these tools for near real-timemanagement of volcanic crises. With this in mind, aseries of potential eruption scenarios have beenselected to identify and characterise which elementsat risk would prove most vulnerable against a specificvolcanic phenomenon, depending on the socio-economiccharacteristics of the area affected and the resultingdistribution of the volcanic products. This kind ofinformation is fundamental to update, adapt or produceeffective risk management and emergency plans orprotocols, where the measures to mitigate or fightagainst a specific volcanic disaster have to be taken,incorporating the existing knowledge of the phenomenonbehaviour and taking into account their potentialeffects on the area of interest.     

GIS Techniques for Mapping Groundwater Contamination Risk

The groundwater contamination risk map of a samplealluvial area was produced by using the IlwisGeographical Information System (GIS) to construct andto overlay thematic maps. The risk map has beenderived from the vulnerability map, the hazard map,where the potential contaminating sources wereidentified, and the socio-economic value of thegroundwater resource, represented by the wells. Thegroundwater quality map allowed thereliability of hazard and risk maps to be tested.The final map shows interesting results and stressesthe need for the GIS to test and improve on thegroundwater contamination risk assessment methods.     

The Risk of Large Volcanic Eruptions and the Impact of this Risk on Future Ozone Depletion

Ozone depletion at mid-latitudes is caused by reactivehalogens from man-made halocarbons. The stratosphericsulphate aerosol which follows large volcaniceruptions enhances (multiplies) this ozone depletion(it has no effect on ozone without halocarbons). Mid-latitude depletion almost doubled for the twoyears after Mt. Pinatubo. Although the MontrealProtocol is expected to reduce atmospheric amounts ofhalocarbons in the 21st century, stratospheric ozonewill be at risk of depletion enhancement by largeeruptions for the next 50 years. Mechanisms ofvolcanoes suggest that large eruptions are random andthat their global rate is constant for severalcenturies. Measurements of large eruptions during thelast 1000 years in ice cores have a remarkable fit toa Poisson distribution, reinforcing the conclusionthat the global incidence is random and at a constantrate for this period. From this rate, the probabilityof one or more eruptions with at least the ozone-lossenhancement of Pinatubo is 58 % in 50 years. Thisprobability is large enough to be of serious concernfor future mid-latitude ozone loss.     

Beyond Modelling: Linking Models with GIS for Flood Risk Management

Spatially explicit hydrodynamic flood models can play animportant role in natural hazard risk reduction. A key element of these models that make them suitable for riskreduction is the ability to provide time-series inundation information about the onset, duration and passingof a hazard event. Such information can be critical for landuse planning, for mapping evacuation egress routes,and for locating suitable emergency shelters to name only a few risk treatments. This research contends that abarrier to effective risk reduction is providing disaster managers with access to model results in a structured andflexible framework that allows consequences of different hazard scenarios to be assessed and mapped. Toaddress these limitations, a framework has been developed that links a commercial relational databasemanagement system with a GIS-based decision support system. The framework utilises industry standard dataexchange protocols and results in efficient time-series hazard data management. A case study based in Cairns,in far-north coastal Australia is presented to illustrate how the system has been developed. Results show that theframework reduces data volumes significantly, while making pre-run modelled inundation results rapidly accessibleto disaster managers. Of note is the ability of the framework to present results in terms of risk to buildings,roads and other spatial features in urban regions, and to provide answers to relatively complex risk questions.     

基于GIS的洪水风险图信息管理系统开发

阐述了基于GIS技术开发的洪水风险图信息管理系统的开发目标、开发环境,列举了系统常用的功能模块及具体功能,根据洪水风险图信息管理系统应具备的功能设计了系统的逻辑结构,并应用于连云港市洪水风险图信息管理系统,取得较好效果.     

Volcanic tremor-source mechanisms and correlation with eruptive activity

Signal characteristics and intensity patterns of volcanic tremor are discussed with regard to eruption phenomena. Although a generally valid relationship cannot be given, volcanic tremor is strongly correlated to the fluid dynamics of the volcano. A major difficulty in the interpretation of volcanic tremor is the lack of an appropriate source model. It is assumed that flow transients of quite different kinds act as seismic sources. The significant correlation of volcanic tremor to external forces (barometric pressure, rain-fall loading, earth tides) is discussed and included in a relation with magma-flow instabilities. Two-phase (liquid-gas) flow instabilities play an essential role in the origin of volcanic tremor and, possibly, in the occurrence of volcanic eruptions. A model is discussed, in which one cause of tremor is seen in self-sustained pressure oscillations following transitions between subsonic and supersonic two-phase magma flow (modified Steinberg and Steinberg model).     

岩土爆破工程危险源辨识、风险评价和控制

简述了岩土爆破工程按《职业健康安全管理体系一规范》（GB／T28001）进行危险源辨识、风险评价和控制的方法,辨识重大危险源,对重大危险源进行控制,减少安全风险,提高安全运行绩效。     

基于GIS技术的全国地面塌陷灾害危险性评价

本文运用GIS的缓冲区、叠加、空间分析等功能,从地貌类型、碳酸盐岩类型、水文地质条件、人类活动及土地利用因素方面,对以岩溶塌陷和采空塌陷为代表的中国地面塌陷灾害危险性进行评价.其中模型中各影响因素的权重值主要是通过层次分析法来确定;而影响因素中的分类值则是地面塌陷点的分布概率.评估结果表明,地面塌陷极高危险区主要分布在中国的广西、贵州、云南,其次是湖北、湖南、重庆、四川、陕西.     

城市地质环境风险性分区评价GIS软件的设计与实现

本文介绍了研究开发出的基于Microsoft VisualC++6.0平台的城市地质环境风险性分区评价GIS软件,包括该系统软件开发的理论和方法及软件开发的必要性、适应性、基本结构、主要功能、设计思路和实现过程。     

Volcanic Eruption Induced Floods. A Rainfall-Runoff Model Applied to the Vesuvian Region (Italy)

Explosive events are commonly accompanied or followed byheavy rains. These eruption-induced storms together with thedeposition of large amounts of ash contribute to destabilise thehydrological cycle in the areas affected by volcanic eruptions.Flooding of the region surrounding the active volcano can easilyfollow, increasing the complexity of the volcanic crisis and itsmanagement. This is particularly true in the case of Vesuvius,that is not only characterized by a dramatic volcanic hazard, butit is also located within an area that is normally prone to flood hazard. A complete assessment of the impact associated with explosive volcaniceruptions should involve a flood hazard assessment for the region.This work represents a first attempt to address the problem: atopographically based rainfall-runoff model was here applied to theVesuvian area where two main sub-basins were analysed. The modelwas applied to evaluate the role of selected parameters on the totaldischarge at the basins' outlet. These parameters were chosen amongthose likely to be affected by an explosive event and were variedthrough a reasonable range. Results confirm that the deposition oflarge amounts of ash can affect the temporal evolution of the dischargeand its maximum value, for a given precipitation event. The simulationspresented outline the need for a detailed flood forecasting study for theVesuvian area, that should be included within the hazard mitigation strategies.     

基于GIS的中国滑坡灾害风险分析

随着我国减灾防灾工作的深入开展,对大范围区域性的滑坡灾害进行风险评估势在必行。GIS技术为滑坡灾害在不同模型条件下的风险评估提供了有效的技术支持。经过多年研究,作者开发出了基于MapGIS软件平台的滑坡灾害风险分析系统。在该系统支持下,采用信息量模型和专家打分模型对我国全国范围内的滑坡灾害进行危险性分析,进而进行区域社会经济易损性分析,并在此基础上进行最终的滑坡灾害风险评估。分析结果具有一定的指导意义和实用价值。     

滑坡风险评估GIS的设计与实现

对地理信息系统在评估过程中的作用进行了详细阐述,着重强调了GIS强大的数据管理、空间分析和空间量算功能在滑坡信息分析中的作用.基于模糊综合评判模型,进行了滑坡风险评估地理信息系统的设计与实现.针对地形地貌、地质条件、气候条件、水文条件、植被条件、人为活动、人口密度、工程设施和土地利用等信息,按致灾指标提取与分析、承灾指...     

基于RS与GIS的层次分析法在滑坡危险性评估中的应用——以四川宣汉天台乡滑坡为例

基于遥感(RS)和地理信息系统(GIS)技术,采用多层次分析(AHP)法,以四川宣汉天台乡为研究区,根据该区实际情况,选取线性构造、道路、土地利用、坡度、坡向5种影响滑坡灾害发生的因素作为评价因子,进行区域滑坡危险性评估。在ArcGIS的空间分析环境中运行权重叠加,把研究区划分成滑坡极易发生区、易发生区、一般发生区、可能发生区、难发生区和极难发生区。通过实地调查和与研究区的滑坡灾害实证研究结果进行比较,发现评估结果与实际状况较为吻合,研究方法能够准确地评估区域滑坡灾害危险性的程度。     

A Spatial-Temporal/3-D Model for Volcanic Hazard Assessment: Application to the Yucca Mountain Region, Nevada

We present a 3-D Poisson model that permits identification and quantification of volcanic phenomena distributed through space and evolving in time (i.e., spatiotemporal data). Specifically, the model: (1) is volcanologically informative in solving problems of volcanic risk/hazard which depends on the location and time of future events; (2) contains model fitting computation algorithms that are efficient; and (3) is flexible enough to handle a large class of volcanic risk/hazard studies. Furthermore, we apply the model fitting techniques developed in this paper to the volcanic data from the Yucca Mountain project to demonstrate a unified volcanic hazard analysis. This study also evaluates the sensitivity of the statistical models developed by experts who have addressed the volcanic hazard/risk assessment problem near the Yucca Mountain region.     

信息量模型在塌岸灾害风险评价中的应用

塌岸灾害风险与塌岸灾害特点及人类社会经济活动密切相关,其风险评价涉及诸多因素.将信息量法应用于塌岸灾害风险预测库,建立了相关的信息量模型及评价指标;以重庆万州区和平广场地段为例,在三峡水库蓄水条件下,分别对塌岸灾害的危险性、易损性、风险性进行了综合预测研究.研究结果表明,塌岸评价指标选取合理,塌岸高危险性的单元与不良地质现象、库岸侵蚀和库岸类型密切相关;塌岸灾害易损性与人类社会经济活动及不良地质现象相关;塌岸高风险区主要集中在塌岸高危险性及高易损性单元,或受人口、建筑物分布影响的塌岸中等危险性的单元.     

地震恢复重建规划区地质灾害特征及危险性评价

通过收集有关资料和实地勘察,描述并总结了四川省青川县板桥乡城建设用地地质灾害的发育特征。根据地质灾害点目前的稳定状态和潜在危害程度,定性评价了区内各地质灾害点的危险性。并基于各地质灾害点的危险程度,综合区内的地形地貌、地质条件和人为因素、气象水文条件,对青）ll县板桥乡地质灾害危险性进行了分区,为建设用地的规划设计提供了依据：     

国内外地质灾害风险管理对比及评述

在了解国内外地质灾害管理背景的基础上, 阐述了国际上开展地质灾害风险管理有代表性的国家或地区在地质灾害管理上的经验和方法, 总结了国内地质灾害风险管理的研究现状。结合实际工作, 对我国现阶段的地质灾害调查、评价、防治工作体系进行了说明。在此基础上, 将国内外地质灾害管理方法做了对比和评述, 最后对如何开展地质灾害风险管理提出了建议。