Flash flood mitigation: recommendations for research and applications

Abstract

New technologies promise reduced flash flood losses. However, real-time observations with vast multi-sensor networks, more precise mapping capabilities using remote sensing and GIS, quicker hydrological and meteorological models, and increasing forecast lead times have not reduced losses. In November, 1999, 35 researchers from nine countries met in Ravello, Italy at a NATO sponsored Advanced Study Institute, to discuss these issues and to develop a research agenda that incorporates the various components required to cope with flash floods. The key recommendations from the Institute were: (1) greater emphasis on increasing understanding of the social processes involved in flash flood warning, particularly in the response phases, and (2) the need to reduce vulnerability in sustainable ways compatible with long-term economic and social goals. The relationship between hydrometeorology and social science is seen as critical to advancing our abilities to cope with flash floods.     

基于硫酸自由基的高级氧化技术研究及应用进展

由于硫酸自由基(SO4-.)具有很高的氧化还原电位,过硫酸盐(S2O82-)活化高级氧化技术作为一种新型氧化技术在环境工程领域具有巨大应用潜能。介绍了热活化、光活化、过渡金属离子三种活化过硫酸盐产生SO4-.的方式,在环境保护方面的现状研究与应用进展,主要涉及受有机污染土壤和地下水的修复、难降解有机废水和废气的处理,阐述了SO4-.高级氧化技术处理各种有机污染物的机理,指出了基于SO4-.的高级氧化技术在处理应用中存在的局限性和未来发展方向。     

乌海市夏季臭氧污染特征及基于过程分析的成因探究

乌海市地形复杂,周边工业园区分布密集,近年来夏季O₃污染问题突出,且污染特征与形成机制尚不明确,分析乌海市O₃变化特征,探究O₃污染形成机制对该区域大气污染防治具有重要意义.本文在分析乌海市2018年6~8月3次持续O₃污染过程特征的基础上,利用WRF-CMAQ模式系统进行模拟并根据过程分析输出结果对污染的成因进行了深入分析,探讨了区域输送和局地光化学反应对乌海市O₃的影响.结果表明,乌海市夏季O₃呈现"单峰"的日变化特征,近地面O₃与向下短波辐射和气温显著呈正相关,与相对湿度呈负相关;空间分布上,乌海市3个工业园区白天和夜间均为O₃低值区,乌海西南部宁夏石嘴山地区、乌海城区和西北部乌兰布和沙漠地区白天为O₃高值区;过程分析结果表明,输送和化学过程及其相对大小对乌海市O₃有决定性影响,6月和7月的污染过程中局地光化学反应和输送共同导致O₃显著升高,且化学过程的影响是输送的两倍左右,8月O₃的升高主要为输送作用的贡献;进一步对输送作用进行分解可知偏南和西北方向的输送对O₃的升高有较大贡献,结合前体物的排放,可能的传输来源为宁夏银川、石嘴山及巴彦淖尔等区域,因此,乌海市应在控制本地排放的基础上,加强区域联防联控,减少区域传输对O₃的影响.     

The representation of cyanobacteria life cycle processes in aquatic ecosystem models

Two simplified versions of a numerical life cycle model for diazotrophic cyanobacteria (of the order Nostocales) are developed and evaluated. Both consider two-life cycle stages, one growing, nitrogen-fixing stage and one stage that combines the resting, germinating and vegetative stages. The versions differ in the vertical resolution of the non-diazotrophic stage: version 1 collects the biomass in one layer at the bottom, version 2 considers sinking and rising of biomass explicitly. The results of the two versions are compared with a complex cyanobacteria life cycle model which describes four different life cycle stages each with two internal quotas for energy and nitrogen. The two simplified approaches show a good agreement with respect to the main characteristics of cyanobacteria dynamics (timing and duration of blooms, magnitude of nitrogen fixation, interannual variability). Our model study shows that both simplified approaches are suitable to be implemented into three-dimensional coastal or lake models.     

Analysis of underlying causes of investigated loss of containment incidents in Dutch Seveso plants using the Storybuilder method

In the Netherlands there are around 400 “Seveso” sites that fall under the Dutch Major Hazards Decree (BRZO) 1999. Between 2006 and 2010 the Dutch Labour Inspectorate's Directorate for Major Hazard Control completed investigations of 118 loss of containment incidents involving hazardous substances from this group. On the basis of investigation reports the incidents were entered in a tailor-made tool called Storybuilder developed for the Dutch Ministry of Social Affairs and Employment for identifying the dominant patterns of technical safety barrier failures, barrier task failures and underlying management causes associated with the resulting loss of control events. The model is a bow-tie structure with six lines of defence, three on either side of the central loss of containment event. In the first line of defence, failures in the safety barriers leading to loss of control events were primarily equipment condition failures, pre start-up and safeguarding failures and process deviations such as pressure and flow failures. These deviations, which should have been recovered while still within the safe envelope of operation, were missed primarily because of inadequate indication signals that the deviations have occurred. Through failures of subsequent lines of defence they are developing into serious incidents. Overall, task failures are principally failures to provide adequate technical safety barriers and failures to operate provided barriers appropriately. Underlying management delivery failures were mainly found in equipment specifications and provisions, procedures and competence. The competence delivery system is especially important for identifying equipment condition, equipment isolation for maintenance, pre-start-up status and process deviations. Human errors associated with operating barriers were identified in fifty per cent of cases, were mostly mistakes and feature primarily in failure to prevent deviations and subsequently recover them. Loss of control associated with loss of containment was primarily due to the containment being bypassed (72% of incidents) and less to material strength failures (28%). Transfer pipework, connections in process plant and relief valves are the most frequent release points and the dominant release material is extremely flammable. It is concluded that the analysis of a large number of incidents in Storybuilder can support the quantification of underlying causes and provide evidence of where the weak points exist in major hazard control in the prevention of major accidents.     

Nestmate recognition in ants is possible without tactile interaction

Ants of the genus Camponotus are able to discriminate recognition cues of colony members (nestmates) from recognition cues of workers of a different colony (non-nestmates) from a distance of 1 cm. Free moving, individual Camponotus floridanus workers encountered differently treated dummies on a T-bar and their behavior was recorded. Aggressive behavior was scored as mandibular threat towards dummies. Dummies were treated with hexane extracts of postpharyngeal glands (PPGs) from nestmates or non-nestmates which contain long-chain hydrocarbons in ratios comparable to what is found on the cuticle. The cuticular hydrocarbon profile bears cues which are essential for nestmate recognition. Although workers were prevented from antennating the dummies, they showed significantly less aggressive behavior towards dummies treated with nestmate PPG extracts than towards dummies treated with non-nestmate PPG extracts. In an additional experiment, we show that cis-9-tricosene, an alkene naturally not found in C. floridanus' cuticular profile, is behaviorally active and can interfere with nestmate recognition when presented together with a nestmate PPG extract. Our study demonstrates for the first time that the complex multi-component recognition cues can be perceived and discriminated by ants at close range. We conclude that contact chemosensilla are not crucial for nestmate recognition since tactile interaction is not necessary.     

Investigating the relationship between air pollution, health and social deprivation in Leeds, UK

This study examines the relationship between air pollution, social deprivation and health in the city of Leeds, UK under a baseline and three distance-based road user charging (RUC) scenarios set at 2 pence, 10 pence and 20 pence/km. Through application of a series of linked models of traffic, emission and pollutant dispersion, air quality was modelled in response to RUC scenarios. The pollutant modelled were NO(2), PM(10), CO, benzene and 1,3-butadiene, though results of NO(2) are used in this study. The RUC scenarios were compared with the 'base' scenario, all set for the year 2005. The RUC initiatives result in the differences in ambient concentrations of NO(2). The study correlates NO(2) concentrations with derived indices of social deprivation and health. The study concludes that positive but weak relationship exists between air quality and social deprivation, and indicates that deprived population groups are disproportionately exposed to higher NO(2) levels. The relationship between air quality and health status of the population is weak. There is a strong relationship between social deprivation and health status of the population. The study concludes that RUC scenarios result in reducing disparity between affluent and deprived populations.     

The Flood Myth in the Age of Global Climate Change

When released, The Day After Tomorrow was widely described by critics and the movie's creators as a pro-environmentalist film. This essay argues that The Day After Tomorrow articulates a variation of apocalyptic discourse identified as a flood myth. The authors conclude that this version of the flood myth largely undermines contemporary environmental discourse that attempts to generate public activism in addressing ecological problems, by replacing an emphasis on human efficacy with symbolic vindication and exchanging collective effort for individual survivalism. The film thus serves as a cautionary tale about the potential consequences of contemporary mythic discourse presented as supporting environmental activism.     

From Environmental Campaigns to Advancing the Public Dialog: Environmental Communication for Civic Engagement

This essay examines the claims of environmental identity campaigns regarding the issue of climate change. Identity campaigns are based on the idea that more effective environmental messages developed through the application of cognitive science by professional communications experts can favorably influence public opinion, and thus support legislative action to remedy this issue. Based on a review of the sociological and psychological literature regarding social change and mobilization, I argue that while this approach may offer short term advantages, it is most likely incapable of developing the large scale mobilization necessary to enact the massive social and economic changes necessary to address global warming. Specifically, theoretical and empirical research on the role of the public sphere, civil society and social movements shows that democratic civic engagement is core to successful social change efforts. However, identity campaigns focus on a communications process that centers on elite led one way communications, which falls to allow for any form of civic engagement and public dialogue. This undermines the creation of a democratic process of change and reinforces the professionalization of political discourse, leading to a weakening of the mobilization capacity over this issue of global warming. The essay concludes with the outlines of an environmental communication process that aims at enhancing civic engagement and democratic decision making.     

New methods for the analysis of invasion processes: multi-criteria evaluation of the invasion of Hydrilla verticillata in Guatemala

The study described in this article incorporates stakeholders' views on aquatic invasion processes and combines expert analysis with information from field work into an evaluation exercise. Management scenarios are designed based on available technical data and stakeholders' perceptions. These scenarios are evaluated using the Social Multi-Criteria Evaluation framework employing the NAIADE model. Two evaluations are carried out, technical and social. Social acceptance of different management scenarios, distribution of costs and benefits, and attribution of responsibility are discussed. The case study was carried out on Lake Izabal, a body of water connected to the Caribbean Sea in Northeastern Guatemala. In 2000, local fishermen reported the presence of an alien species in the lake, the macrophyte Hydrilla verticillata. Two years later, this alien species was established around the entire lakeshore, damaging the ecosystem, endangering native species and the subsistence of local inhabitants through impacts on transportation, fishing practices, and tourism.