Natural disasters and climate change beliefs: The role of distance and prior beliefs     

《Global Environmental Change》2022

Public support of climate policies crucially depends on climate change beliefs. Here we analyze the effects of natural disaster experience on the belief in the existence of climate change. The primary data source is a panel survey covering 22,251 observations from 11,194 geo-located households collected in Germany between 2012 and 2015, combined with satellite imagery of a major flood event in 2013. We find that flood experience had a significant positive effect on the beliefs in the existence of climate change for those respondents living close to the flooded area. However, the effect decreases sharply with distance. We further show that this overall effect is driven by those respondents who already believed in climate change before the flood – they saw their belief confirmed by their experience. In contrast, spatial proximity to the flood had no measurable effect on skeptics. These results imply that climate skeptics may not be influenced by the experience of natural disasters at their doorsteps.  相似文献   

Evolution of an incised valley system in the southern Adriatic Sea (Apulian margin): an onshore–offshore correlation     

Vincenzo De Santis  Massimo Caldara 《Geological Journal》2016,51(2):263-284

Seismic surveys with sub‐bottom profiler were carried out in the Manfredonia Gulf in the southern Adriatic Sea. Here, a buried surface was recognized on which three valleys, located about 80 km from the shelf edge, were deeply incised. Beneath this surface, a pre‐upper Würm seismic unit (PW) was identified. Above, two seismic units were recognized: the transgressive system tract (TST) and highstand system tract (g₂)_. On the basis of regional correlation with onshore and offshore data, these units and their boundaries were dated and correlated with phases of the last glacial–interglacial cycle. The incised valley system was attributed to the Marine Isotopic Stage (MIS) 2. The TST and g₂ units fill the valleys and were attributed to the post‐glacial sea‐level rise and highstand. The incised valleys are anomalous with respect to published models; despite having many characteristics that would have limited the fluvial incision (the lowstand shoreline that remained on the shelf, the low gradient of the shelf, the subsidence that affected the study area since MIS 5), the valleys appear to be deeply incised on the shelf, with valley flanks that can exceed 40 m in height. The model to explain the formation of the valleys comprises enhanced river discharge as the key factor in increasing river energy and promoting erosion across the low gradient shelf. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

淮河梅雨洪涝与西太平洋副热带高压季节推进异常   总被引：11，自引：4，他引：7  

刘屹岷  洪洁莉  刘超  张鹏飞 《大气科学》2013,37(2):439-450

基于台站观测和卫星观测资料及再分析数据集,本文研究了6月淮河洪涝发生时中国东部降雨型及与雨带异常相联系的环流特征、环流的季节推进异常及其机理.结果发现6月淮河流域洪涝与亚洲环流和中国东部降水联合模态的第二模态密切相关.该模态在我国东部降水表现为以长江为界北增南减的“梅雨偶极型”分布,对应的低层风场呈现出倾斜的以台湾为界,以南西太平洋是异常气旋环流,以北为反气旋环流,即西太平洋副热带高压偏北,淮河流域上存在异常西南风;同时阿拉伯海上是异常反气旋,印度上空西风偏强、降水显著偏多.这些特征是东亚和西太平洋季风区季节推进超前的反映,且与前期春季澳大利亚东北向海域海洋热含量异常偏高显著相关.该关键区海洋热含量变化是太平洋热含量变化第一模态——三极型变化的一部分,即当菲律宾以东的西太平洋和澳大利亚东北向海域海洋热含量增加,赤道中东太平洋热含量减少.该三极型海洋热含量异常从春到夏信号稳定,它激发正感热加热异常控制菲律宾以东到夏威夷以北的广大热带—副热带西太平洋地区,其北侧黑潮延伸区为负感热区.两者共同作用激发出局地反气旋在北、气旋在南,使对流层低层西太平洋副热带高压偏北.因此春季三极型海洋热含量通过影响对流层低层西太平洋副热带高压异常北移对东亚—西太平洋季节推进提前和6月淮河梅雨洪涝发生起重要作用,可作为季节预测的前期因子之一.  相似文献   

Diversion of Flooding Rivers to Residual Mining Open Pits     

Ian Lerche 《Natural Resources Research》2008,17(3):181-186

Massive flooding in East Germany in the summer of 2002 was first alleviated, and then exacerbated, by diversion of the river flood waters into residual open pits, the legacy of lignite mining. The pits at first contained the flood waters but, once filled to capacity, leaked precipitously, causing massive flooding in the flat lands around the pits. This article examines the problem of constructing quantitative models for assessments of fill, bypass, and leakage from such floodwater containing pits. Emergency management teams can then generate quickly not only many different scenarios to help with immediate flood control options and fall-back positions, but can also investigate long-term planning that can then be undertaken to estimate better the consequences of permitting such diversion. While the models developed are simple, and are numerically implemented in easy to use spreadsheet format, they have the advantage of guiding directions of flood assessment control and consequent results. The illustrative numerical examples show how one can quickly use such quantitative models to obtain patterns of flooding relevant to situations of sustained, torrential rainfall, and subsequent river overflow.  相似文献   

Assessment of rockfall susceptibility by integrating statistical and physically-based approaches   总被引：7，自引：1，他引：6  

Paolo Frattini  Giovanni Crosta  Alberto Carrara  Federico Agliardi 《Geomorphology》2008,94(3-4):419

In Val di Fassa (Dolomites, Eastern Italian Alps) rockfalls constitute the most significant gravity-induced natural disaster that threatens both the inhabitants of the valley, who are few, and the thousands of tourists who populate the area in summer and winter.To assess rockfall susceptibility, we developed an integrated statistical and physically-based approach that aimed to predict both the susceptibility to onset and the probability that rockfalls will attain specific reaches. Through field checks and multi-temporal aerial photo-interpretation, we prepared a detailed inventory of both rockfall source areas and associated scree-slope deposits. Using an innovative technique based on GIS tools and a 3D rockfall simulation code, grid cells pertaining to the rockfall source-area polygons were classified as active or inactive, based on the state of activity of the associated scree-slope deposits. The simulation code allows one to link each source grid cell with scree deposit polygons by calculating the trajectory of each simulated launch of blocks. By means of discriminant analysis, we then identified the mix of environmental variables that best identifies grid cells with low or high susceptibility to rockfalls. Among these variables, structural setting, land use, and morphology were the most important factors that led to the initiation of rockfalls.We developed 3D simulation models of the runout distance, intensity and frequency of rockfalls, whose source grid cells corresponded either to the geomorphologically-defined source polygons (geomorphological scenario) or to study area grid cells with slope angle greater than an empirically-defined value of 37° (empirical scenario). For each scenario, we assigned to the source grid cells an either fixed or variable onset susceptibility; the latter was derived from the discriminant model group (active/inactive) membership probabilities.Comparison of these four models indicates that the geomorphological scenario with variable onset susceptibility appears to be the most realistic model. Nevertheless, political and legal issues seem to guide local administrators, who tend to select the more conservative empirically-based scenario as a land-planning tool.  相似文献   

Diagenesis in Okavango fan and adjacent dune deposits with implications for the record of palaeo-environmental change in Makgadikgadi–Okavango–Zambezi basin, northern Botswana   总被引：1，自引：0，他引：1  

Susan Ringrose  Philippa Huntsman-Mapila  William Downey  Stephan Coetzee  Martin Fey  Cornelis Vanderpost  Bernard Vink  Thebe Kemosidile  Dikitso Kolokose 《Geomorphology》2008,101(4):544-557

This work considers the spatial distribution and ages of western MOZ basin siliclastic sediments prior to providing insights into the diagenesis of degraded dune and alluvial fan sands. Previously published and new TL/OSL ages imply that extensive over-washing of dune sands took place at least 100 ka ago while ages on Okavango floodplains imply that the fan was formed ca. 40 ka and has since undergone periods of higher and lower flood regimes. Sediment analyses indicate that both dune and fan sands contain a diagenetic matrix of clay-enhanced amorphous silica (CEAS) which bonds weakly formed aggregates. The time of formation of diagenetic matrix products is inconclusive but may have been accelerated during or shortly after events dated using OSL/TL techniques. Hence earlier dune over-washing may have led to greater porewater of an acidic to near neutral nature which in turn promoted smectite formation and silicic acid precipitation > 100 000 years ago. The relatively abundant CEAS matrix in floodplain sands implies more recent semi-continuous flood events again of an acidic-near neutral nature leading to the formation of smectite. In this case the floodplain sediments are dated as having been deposited around 40 and 11 ka, when porewater content may have accelerated clay formation and silica dissolution. The dual nature of the CEAS in the islands reflects a changing environment from smectite-dominated flooding events to sepiolite-dominated desiccation events. Flooding may also correspond to TL/OSL ages over the past 40 000 years which contributed to accelerated CEAS formation. The sepiolite is associated with a Ca-rich matrix implying desiccation which may relate to drying events over the 40 000 year period or to riparian tree root pumping and selective salt accumulation. This work shows that sedimentation in incipient rifts is complex and rarely explained totally in terms of primary depositional events. The implications of different stages of sand diagenesis may be significant in enhancing palaeo-environmental interpretations in semi-arid fluvial environments.  相似文献   

Evaluating the utility of the ensemble transform Kalman filter for adaptive sampling when updating a hydrodynamic model   总被引：1，自引：0，他引：1  

Jeffrey C. Neal  Peter M. Atkinson  Craig W. Hutton 《Journal of Hydrology》2009,375(3-4):589-600

This paper compares two Monte Carlo sequential data assimilation methods based on the Kalman filter, for estimating the effect of measurements on simulations of state error variance made by a one-dimensional hydrodynamic model. The first method used an ensemble Kalman filter (EnKF) to update state estimates, which were then used as initial conditions for further simulations. The second method used an ensemble transform Kalman filter (ETKF) to quickly estimate the effect of measurement error covariance on forecast error covariance without the need to re-run the simulation model. The ETKF gave an unbiased estimate of EnKF analysed error variance, although differences in the treatment of measurement errors meant the results were not identical. Estimates of forecast error variance could also be made, but their accuracy deteriorated as the time from measurements increased due in part to model non-linearity and the decreasing signal variance. The motivation behind the study was to assess the ability of the ETKF to target possible measurements, as part of an adaptive sampling framework, before they are assimilated by an EnKF-based forecasting model on the River Crouch, Essex, UK. The ETKF was found to be a useful tool for quickly estimating the error covariance expected after assimilating measurements into the hydrodynamic model. It, thus, provided a means of quantifying the ‘usefulness’ (in terms of error variance) of possible sampling schemes.  相似文献   

Rainfall-driven Episodic Flood Events: are they a major factor in moulding New South Wales arid land vegetation patterns?     

Martin E. Westbrooke 《The Australian geographer》2005,36(2):171-181

Episodic high rainfall has been proposed as an important factor in perennial species recruitment but flooding based on rainfall at a distance from the site has received little attention. Although such flood events in arid Australia are rare, studies of the ephemeral Olary Creek indicate that occasional floods can also have a high impact on the vegetation and landscape. During February 1997, a high-rainfall event caused flooding in the Olary Creek. One branch of the creek created a terminal lake within mallee vegetation on Nagaela Station in far-western New South Wales. The flood path of Olary Creek and this terminal lake allow study of the importance of rainfall-driven flood events in shaping vegetation in arid environments. This paper reports (i) the response of arid land plant species to high-rainfall-driven episodic flood events and (ii) how grazing pressure from native and introduced herbivores can impact on native species response.

A systematic study was conducted to understand the botanical composition in flooded and control areas based on 25 m² fenced and unfenced plots subjected to flooding and non-flooding. For 6 years following flooding, species richness in the flooded area was twice that of unflooded areas. In particular, 27 native species from 13 families were recorded both in the enclosed and open plots located in the flooded area. Over the study period nine species: Brachyscome ciliaris, Helichrysum leucopsidium, Vittadinia cuneata, Casuarina pauper, Maireana sedifolia, Salsola kali, Sclerolaena obliquicuspis, Eremophila sturtii and Eucalyptus foecunda germinated only in the flooded enclosed plots. Further, 11 exotic species from five families were recorded in the flooded (both enclosed and open) plots over the study period. Knowledge gained from this study will contribute to management strategies for arid land vegetation.  相似文献   

The interfaces of public and private adaptation: Lessons from flooding in the Deerfield River Watershed     

《Global Environmental Change》2016

Successful adaptation to climate risks will depend on the outcomes of many coordinated and uncoordinated actions. Key will be ensuring public and private adaptations undertaken at a variety of scales do not undermine one another. To improve understandings of how adaptive responses accumulate, we investigate interactions between public and private efforts to mitigate flood hazards in the Deerfield River Watershed, located in Western Massachusetts, USA. Through interviews, we uncover the manner in which private adaptations, undertaken by landowners seeking to protect their land from flood impacts, are both determined in response to and have an effect on public adaptations seeking to address flood impacts across the watershed. Landowners respond to public adaptations based on their perceptions of the appropriateness of adaptive pathways including how they view the effectiveness of adaptive action and how the actions fit with the social contract. As a result, the interface between public and private adaptations takes various forms: commutable, attenuating, synergistic, or countervailing. Our findings underscore how, in areas with high geo-physical connectivity and where responsibility is dispersed across private and public entities, anticipating and responding to multiple interfaces between public and private adaptations is needed for public adaptations to achieve the best cumulative outcomes.  相似文献   

Brutal presence or convenient absence: The role of the state in the politics of flooding in informal Accra,Ghana     

《Geoforum》2016

This paper argues that human vulnerability to flood hazards in urban slums in developing countries is greatly affected by the positioning and activities of their city governments. As a result, the paper explores the central role of city authorities in the production of flood vulnerability in selected informal settlements in Accra, Ghana. Using a case study research design, the study draws on multiple qualitative methods to gather evidence including: document review, focus group discussions, flood victims’ interviews, institutional consultation and field observation. The paper reveals two main positions of state and city authorities in Accra’s perennial floods: first, being present and complicit in informal urbanization through their involvement in the politics of land management in flood prone zones; and second, being absent through their inaction in informal growth in flood-risk areas. To each of these positions of the urban state, there are emerging responses from residents and other non-state actors operating within and outside these informal communities. The paper proposes a re-examination of the current structure and processes of urban governance, state-community engagements and urban citizenship in informal communities.  相似文献