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171.
Groundwater pollution risk mapping for the Eocene aquifer of the Oum Er-Rabia basin, Morocco 总被引:2,自引:0,他引:2
Said Ettazarini 《Environmental Geology》2006,51(3):341-347
Sustainable development requires the management and preservation of water resources indispensable for all human activities. When groundwater constitutes the main water resource, vulnerability maps therefore are an important tool for identifying zones of high pollution risk and taking preventive measures in potential pollution sites. The vulnerability assessment for the Eocene aquifer in the Moroccan basin of Oum Er-Rabia is based on the DRASTIC method that uses seven parameters summarizing climatic, geological, and hydrogeological conditions controlling the seepage of pollutant substances to groundwater. Vulnerability maps were produced by using GIS techniques and applying the “generic” and “agricultural” models according to the DRASTIC charter. Resulting maps revealed that the aquifer is highly vulnerable in the western part of the basin and areas being under high contamination risk are more extensive when the “agricultural” model was applied. 相似文献
172.
中国旱灾农业承灾体脆弱性诊断与评价 总被引:9,自引:0,他引:9
旱灾是世界上影响面最广、造成农业损失最大的自然灾害类型,世界近一半的国家干旱严重。中国旱灾频繁,每年旱灾损失占各种自然灾害损失的15%以上,随着人口和农业的快速发展,农业承灾体脆弱性对灾情的放大也在增加。基于灾害系统理论,从致灾因子和耕地承灾体的区域组合角度,在旱灾频发高值区,选择雨养农业、灌溉农业和水田农业为主要承灾体类型,构建了农业旱灾脆弱性生产压力和生活压力,灾前—灾中易损性和灾中—灾后适应性等农业旱灾承灾体脆弱性诊断指标体系。提出脆弱性评价的区域模型,即:雨养农业的易损—适应模型(兴和)、灌溉农业的生产—生活压力模型(邢台)和水田农业的需水—灌水模型(鼎城)。基于农业承灾体脆弱性评价,提出制定适应降水变化的波动土地利用结构调整区域政策、建立农业生态—生产范式、建立“水银行”管理机制、建立用水效益和开源节流的评估体系以及加强“截水—抽水—控水”为一体的灌溉系统工程建设,提高灌溉应急能力等对策,以期为农业旱灾的防御和区域粮食安全决策提供科学依据。 相似文献
173.
Earthquake risk assessment of lifelines 总被引:4,自引:0,他引:4
Kyriazis Pitilakis Maria Alexoudi Sotiris Argyroudis Olivier Monge Christophe Martin 《Bulletin of Earthquake Engineering》2006,4(4):365-390
This paper presents the RISK-UE methodology for the seismic risk assessment of utility systems (potable water, waste-water, gas system, telecommunication, electric power) and transportation infrastructures (port, airport, road and railway system). The proposed methodology provides a uniform basis for the reduction of the consequences of lifeline damages in urban areas and an efficient mitigation strategy and prioritization policies for pre-earthquake and post earthquake actions. A detailed inventory for every element at risk together with a reliable seismic hazard assessment, appropriate selection of fragility models, estimation of the “global value” and economical impact of lifeline damages and losses are the main steps of the proposed methodology. The consideration of European distinctive features of lifelines and utility systems in the construction of seismic scenarios and the proposition of fragility curves are among the basic aims of the proposed methodology. Different modules of the methodology were applied in seven pilot cities (Thessaloniki, Catania, Nice, Bucharest, Sofia, Barcelona, Bitola). We present herein few representative examples (case studies) in order to illustrate the methodology and to prove its efficiency. 相似文献
174.
Trends in landslide occurrence in Nepal 总被引:2,自引:0,他引:2
David N. Petley Gareth J. Hearn Andrew Hart Nicholas J. Rosser Stuart A. Dunning Katie Oven Wishart A. Mitchell 《Natural Hazards》2007,43(1):23-44
Nepal is a mountainous, less developed kingdom that straddles the boundary between the Indian and Himalayan tectonic plates.
In Nepal, landslides represent a major constraint on development, causing high levels of economic loss and substantial numbers
of fatalities each year. There is a general consensus that the impacts of landslides in countries such as Nepal are increasing
with time, but until now there has been little or no quantitative data to support this view, or to explain the causes of the
increases. In this paper, a database of landslide fatalities in Nepal has been compiled and analysed for the period 1978–2005.
The database suggests that there is a high level of variability in the occurrence of landslides from year to year, but that
the overall trend is upward. Analyses of the trends in the data suggest that there is a cyclicity in the occurrence of landslide
fatalities that strongly mirrors the cyclicity observed in the SW (summer) monsoon in South Asia. Perhaps surprisingly the
relationship is inverse, but this is explained through an inverse relationship between monsoon strength and the amount of
precipitation in the Hill District areas of Nepal. It is also clear that in recent years the number of fatalities has increased
dramatically over and above the effects of the monsoon cycle. Three explanations are explored for this: land-use change, the
effects of the ongoing civil war in Nepal, and road building. It is concluded that a major component of the generally upward
trend in landslide impact probably results from the rural road-building programme, and its attendant changes to physical and
natural systems. 相似文献
175.
Generation of a landslide risk index map for Cuba using spatial multi-criteria evaluation 总被引:5,自引:2,他引:5
This paper explains the procedure for the generation of a landslide risk index map at national level in Cuba, using a semi-quantitative
model with ten indicator maps and a cell size of 90 × 90 m. The model was designed and implemented using spatial multi-criteria
evaluation techniques in a GIS system. Each indicator was processed, analysed and standardised according to its contribution
to hazard and vulnerability. The indicators were weighted using direct, pairwise comparison and rank-ordering weighting methods,
and weights were combined to obtain the final landslide risk index map. The results were analysed per physiographic region
and administrative units at provincial and municipal levels. The Sierra Maestra mountain system was found to have the largest
concentration of high landslide risk index values while the Nipe–Cristal–Baracoa system has the highest absolute values, although
they are more dispersed. The results obtained allow designing an appropriated landslide risk mitigation plan at national level
and to link the information to the national hurricane early warning system, allowing also warning and evacuation for landslide-prone
areas. 相似文献
176.
A GIS-based decision support system, which incorporates local topographic and rainfall effects on debris flow vulnerability
is developed. Rainfall at a scale compatible with the digital elevation model resolution is obtained using a neural network
with a wind-induced topographic effect and rainfall derived from satellite rain estimates and an adaptive inverse distance
weight method (WTNN). The technique is tested using data collected during the passage of typhoon Tori-Ji on July 2001 over
central Taiwan. Numerous debris flows triggered by the typhoon were used as control for the study. Our results show that the
WTNN technique outperforms other interpolation techniques including adaptive inversed distance weight (AIDW), simple kriging
(SK), co-kriging, and multiple linear regression using gauge, and topographic parameters. Multiple remotely-sensed, fuzzy-based
debris-flow susceptibility parameters are used to describe the characteristics of watersheds. Non-linear, multi-variant regressions
using the WTNN derived rainfall and topography factors are derived using self-organizing maps (SOM) for the debris flow vulnerability
assessment. An index of vulnerability representing the degrees of hazard is implemented in a GIS-based decision support system
by which a decision maker can assess debris flow vulnerability. 相似文献
177.
Impacts from the 2004 Indian Ocean Tsunami: analysing the potential protecting role of environmental features 总被引:2,自引:0,他引:2
The tsunami that deeply impacted the North Indian Ocean shores on 26 December 2004, called for urgent rehabilitation of coastal
infrastructures to restore the livelihood of local populations. A spatial and statistical analysis was performed to identify
what geomorphological and biological configurations (mangroves forests, coral and other coastal vegetation) are susceptible
to decrease or increase coastal vulnerability to tsunami. The results indicate that the width of flooded land strip was, in
vast majority, influenced by the distance to fault lines as well as inclination and length of proximal slope. Areas covered
by seagrass beds were less impacted, whereas areas behind coral reefs were more affected. The mangroves forests identified
in the study were all located in sheltered areas, thus preventing to address the potential protecting role of mangroves forests. 相似文献
178.
The focus of this study is on how changes in formal and informal institutions have differential impacts across populations in terms of vulnerability of livelihoods to drought, and the unequal processes that shape adaptation to new conditions. Drought vulnerability occurs as a result of exposure and sensitivity to interrelated economic, social, political, and ecological dynamics. There is a need for approaches that can evaluate how the ability to reduce these exposures and sensitivities becomes socially stratified. Building on our understanding of institutional and biophysical constraints in one pastoralist group ranch, we use an approach that draws on quantitative and qualitative data to combine analyses of entitlements, access, and adaptive capacity. We asked how, in a context of changing herding institutions, the ability to adapt to drought and other stressors, is differentiated among actors. We found that herders with higher livestock wealth are more likely to have entitlement sets that include factors that enable access to secure cattle grazing on private wildlife conservation lands, and access to more distant areas with herds of sheep and cattle – two key means of reducing exposure to drought vulnerability, leading to greater coping ability during drought. Those with lower livestock wealth rely disproportionately on illicit, precarious access to external grazing resources. Higher livestock wealth families experienced disproportionately lower sensitivity to drought with smaller losses of cattle, and likely have decreased sensitivity to drought-related market fluctuations, while others are primarily reliant on small stock and/or precarious access pathways. However, rather than naturalize this differential ability as merely increased adaptive capacity for some that are better able to adapt to novel, local conditions, we argue this instead reflects the unequal footing that households find themselves on, in a shifting institutional landscape of structural and relational access constraints and reconfigurations of reciprocity, that are intertwined with interventions by state and non-state actors. 相似文献
179.
The recent global increase in extreme heat events linked to climate change is projected to continue. The additive effect of urban heat islands from impervious surfaces and urban heat emissions (e.g., from transportation and building cooling) exacerbates extreme heat events in urban areas, exposing dense populations to extreme heat with implications for human health. Ground- and satellite-based data on urban and suburban temperatures and vegetation over a historical period can help identify temporal and geospatial trends in heat exposure. A set of indicators has been developed to map the exposure, social sensitivity, and vulnerability of urban populations to heat wave health impacts. Guided by an Advisory Group of local planners in the pilot city of Philadelphia, localized trends of increasing urban extreme heat events using MODIS Land Surface Temperature (LST) data, confirmed with urban and non-urban temperature monitor data were identified. For the Philadelphia study area, the number of heat-event days in the urban setting has increased from approximately 4 days in 1980 to almost 12 days in 2013, while the non-urban setting has consistently experienced 5 days of heat events per year across the time period. Warmer micro-climates with limited vegetative cooling and elevated LSTs were also identified. The exposure indicator was combined with areas of high social sensitivity (e.g., low-income and elderly) to create a vulnerability indicator, showing significant overlap between highly exposed and highly sensitive populations. As a measure of the adaptive capacity of local governments to reduce the urban heat island, evidence of targeted vegetation increases or reduced localized temperatures linked to urban greening and cooling programs were sought, though none were of a scale to be identified by the 1 km satellite data utilized. The indicators have helped local decision makers to understand patterns of vulnerability, and may be used in the future to target adaptation actions and measure results (LST reduction or vegetation increase) from existing adaptation actions. 相似文献
180.
由于研究对象、目的、数据、方法等方面的不同,自然科学和社会科学的协同存在着非常大的困难,近20年来,气候变化、环境、生态、能源、粮食、资源、灾害、健康等跨学科交叉研究的兴起,为自然科学和社会科学协同带来了新的契机。为克服自然科学和社会科学协同的困难,首先要开展"以解决问题为导向"的研究,从项目初始就贯彻"协同设计、协同实施"的理念,将政府和社会作为全球变化与可持续性研究的服务对象。在研究对象的空间尺度协同上,通过自然科学的降尺度和社会科学的升尺度,在局域尺度上开展气候变化脆弱性与适应研究是实现自然科学和社会科学协同的基础。同时,正确理解和沟通科学的不确定性是自然科学和社会科学协同的重要环节,进行观测数据及调查资料的协同是未来自然科学和社会科学协同成功的关键。最后,对自然科学和社会科学协同中沟通和交流的鸿沟以及人才培养、重理轻文倾向、跨学科研究的评价标准等问题进行了思考和讨论。 相似文献