The role of science in federal policy development on a regional to global scale: Personal commentary

Nutrient enrichment of coastal waters is an example of the large-scale, highly complex environmental challenges facing decision makers today. Conventional monitoring networks and advanced observational capabilities permit the detection of changes in the environment at continental to global scales (e.g., hypoxia in the Gulf of Mexico, aerosol plumes stretching across the ocean, global atmospheric enrichment of carbon dioxide). Much more knowledge is needed, however, to fully understand the societal consequences of environmental change and of actions taken to address them. This paper discusses the emerging role of assessment in developing effective U.S. policy responses to large-scale, complex environmental change while improving the scientific understanding of the problem. In the cases of global climate change and coastal hypoxia, the U.S. Congress passed legislation authorizing assessments recognizing that decision making must proceed in the face of scientific uncertainty. Evaluating the state of knowledge is usually the first step in an assessment in order to provide a picture of what is known and where there are knowledge gaps. Assessments should also provide the policy maker with an idea of the level of uncertainty, how long it may take to reduce the uncertainty, what information is most critical to resolve, and the consequences and benefits of the various management options. In this paper I draw upon several examples from national assessments, including those of climate change impacts on the U.S. and relationships between Mississippi River water and Gulf of Mexico water quality, to illustrate the strengths and difficulties of using science and assessment to inform the policy process.     

Knowing wildfire risk: Scientific interactions with risk mitigation policy and practice in Victoria,Australia

Over the past decade, major landscape wildfires (or ‘bushfires’ in Australia) in fire-prone countries have illustrated the seriousness of this global environmental problem. This natural hazard presents a complex mesh of dynamic factors for those seeking to reduce or manage its costs, as ignitions, hazard behaviour, and the reactions of different human and ecological communities during and after hazard events are all extremely uncertain. But while those at risk of wildfire have been subject to significant research, the social dimensions of its management, including the role of science, have received little attention. This paper reports on a case study of the Barwon-Otway area of Victoria in Australia, a high wildfire risk area that has recently been a pilot site for a new risk mitigation strategy utilising the wildfire simulation model PHOENIX RapidFire. Against simple equations between ‘more science’ and ‘less uncertainty,’ this paper presents results from interviews and a workshop with practitioners to investigate how scientific research interacts with and informs both wildfire policy and practice. We suggest that attending to cultural and social specificities of the application of any technical innovation—such as next generation modelling—raises questions for future research about the roles of narrative, performance, and other knowledges in the sedimentation of science.     

强胁迫力使脆弱环境突变--松辽平原百年开发史例证

以松辽平原为案例,首次提出并论证了"人类强胁迫力作用于脆弱环境系统必将导致生态环境突变"的命题。而这种突变机理又对"人类力是现代环境变化的第一驱动力"的论点提供支持。文章运用了区域学原理,对区域综合要素进行了分析,判定区域属于脆弱系统;运用地理景观理论,构建了距今约150年、100年、50年和现今(2000年)共4个时期的区域生态景观模型,揭示出人类逐阶强化胁迫的过程,并结合遥感分析,首次识别出松辽平原大面积荒漠和半荒漠;引进系统突变模型,论证了生态环境突变过程的存在及所特有的快速扩张性,可导致重大生态灾难--荒漠化过程失控。文章建议应认真研究中国广大地带的环境突变问题,制定科学合理的环境战略,应对全球环境变化的挑战。     

Peculiarities of tsunamis generated by Asteroid impact or nuclear explosions in the northwest of Black Sea

Different models are used to evaluate the seashore effects of the tsunami generated by an asteroid impacting the shallow-water plateau in the northwest basin of the Black Sea. The shortest distance between the impact location and the coast is about 185 km. The tsunami’s effects on the coastal regions depend on many factors among which the most important is asteroid size. The tsunami generated by a 250-m asteroid reaches the nearest dry land location in 35 min and needs about 2 h to arrive all over the Black Sea coast. The run-up value is about 2 m high on Turkish and Crimean coasts. In the western Black Sea regions, the wave height is about 3 m. The run-up values strongly depend on bathymetry and topography peculiarities. The run-up values in case of the tsunami generated by a 1,000-m-sized asteroid are up to five to six times larger than in case of the 250-m impactor, depending on location. Differences between the tsunami’s dynamics on coastal regions situated in the proximity of deep water and shallow water, respectively, are outlined. Aspects concerning accidental or deliberate nuclear explosions are briefly referred. Possible social consequences and prevention are shortly discussed.     

区域研究：全球变化研究的重要途径

区域研究是全球变化研究的重要途径。国际上南部非洲、南亚、东亚、东南亚4个地区及若干重大区域研究项目如 LBA、AMMA、MAIRS及ProMed等典型案例研究表明：区域研究是全球变化研究的基础，区域的实验、模拟、分析是全球环境变化研究的有效方法。区域研究应关注：陆地表面过程、海岸带的陆—海相互作用过程、区域气候变化过程等关键过程对全球变化的响应及作用；区域边缘现象、阈值与突变问题；区域人类活动对全球变化的有序适应等。有必要制订国际区域研究计划，实施地球系统的区域观测，建立区域研究的集成新方法、区域实验与尺度转换方法，建立基于数理基础的区域地球系统模型和数值模拟等新方法。     

区域生态风险评价

生态风险评价是伴随着环境管理目标和环境观念的转变而逐渐兴起并得到发展的一个新的研究领域，它区别于生态影响评价的重要特征在于其强调不稳定性因素的作用，区域生态风险评价所涉及的风险源以及评价受体等都在区域内具有空间异质性，因而比一般生态风险评价更复杂。通过讨论区域生态风险评价的特点和方法论基础，对有关概念和评价的方法步骤进行了理论探讨。     

Role of nuclear energy,geothermal energy,agriculture, and urbanization in environmental stewardship

The global issue of atmospheric variations and global warming caused by diverse anthropogenic behaviors is a global concern. There is apprehension about preserving an uncontaminated atmosphere and attaining optimal nuclear and geothermal energy utilization with agriculture sector development. In this regard, this paper investigates the influence of nuclear energy, geothermal energy, agriculture development, and urbanization on carbon emissions and ecological footprint from 1990Q1 to 2019Q4 in the case of China. The findings of unit root tests reveal that all variables are stationary at first integration order, and cointegration test findings confirm the presence of long-run relationships among series. The quantile autoregressive distributive lag (QARDL) method findings demonstrate that nuclear energy, geothermal energy, and urbanization statistically correlate with CO2 emissions and ecological footprint across all quantiles, indicating that these determinants have contributed to environmental degradation. Whereas agricultural development has a statistically significant and negative influence on the environment, implying that agriculture has a pollution-mitigation impact. Based on these empirical findings, several policy implications are presented to preserve environmental quality to achieve the 2030 Sustainable Development Goals (SDGs) target.     

成像光谱地物识别影响因素的不确定性浅析--以矿物识别为例

成像光谱以其超高的光谱分辨率影像和精细的地物光谱成像能力,已经广泛地应用在地质、环境保护和生物学等领域.受多种不确定性因素影响,成像光谱地物识别从数据获取和处理到应用决策都存在不确定性.这种不确定性又可以分为基于误差的不确定性和基于变异的不确定性.文章以矿物识别为例,从机理的角度探讨了影响数据层面的上述不确定因素,指出虽然成像光谱地物识别受各种因素影响,但地物光谱的形成机理决定了这种不确定性是可以消除的.并给出一些常见的解决理论和方法.     

Dam break threshold value and risk probability assessment for an earth dam

In dam safety assessment, it is customary to focus on stability analysis, and the safety factor is regarded as an assessment index that cannot correctly reflect the effect of multi-factors and variable uncertainty. The factors that induce dam breaks are complex and uncertain; however, three primary ones can be identified: hydrological factors, seepage and bank slope instability. In this paper, the risk probability and the dam break threshold value for each factor individually, as well as coupled factors, are studied. The threshold value is acquired using the relationship formula between risk probability and dam type. The Dongwushi reservoir located in the Hebei province of China is taken as a case study. The results show that the dam break threshold values for hydrological factors, seepage and bank slope instability are 2.53, 2.02 and 2.69, respectively. The integrated dam break threshold value for the coupled factors is 1.25, which indicates that the dam is under serious stress according to the established risk assessment standard. The safety factor is calculated as 1.15 using the Bishop method, which indicates that the dam is under serious stress. The results obtained by the proposed method are consistent with those of the Bishop method. Finally, the proposed theory and method are introduced into a dam safety evaluation system (DSES) for convenient and efficient dam safety management.     

Chelyabinsk event as an astronomical phenomenon

The fall of a meteorite near the town of Chelyabinsk is considered from the viewpoint of astronomy, and the major witness facts and entry characteristics (including the measured entry velocity and the height of the explosion) are analyzed. The aerodynamic phenomena that accompanied the entry of the meteorite in the atmosphere at an ultrasonic velocity and the origin of a shock wave that induced damage on the Earth’s surface are analyzed. The paper also reports the estimated frequency of the falls of celestial bodies depending on their size, and consequences of collisions of these bodies with the Earth. It is emphasized that studies of small bodies in the Solar System can provide insight into the origin of the protoplanetary disk and the processes that produced the planets. The studies of small bodies, such as the Chelyabinsk meteorite, are directly related to the problem of asteroid and comet impact hazard (ACIH). The paper reports the sizes of potentially hazardous celestial bodies whose monitoring requires the deployment of a network of specialized telescopes on the Earth to mitigate ACH and a system of space-based systems for the identification and monitoring of such bodies in near space.     

土壤有机碳的主导影响因子及其研究进展

土壤有机碳库是全球碳循环的重要组成部分，其积累和分解的变化直接影响全球的碳平衡。理解土壤有机碳蓄积过程对生物、物理和人为因素的响应，把握关键的控制因子是准确预测土壤有机碳在全球变化情景下对大气CO 2的源／汇方向及准确评估碳收支的关键。综述了土壤有机碳主导影响因子的研究进展，并针对陆地碳循环特点，提出未来土壤有机碳研究应加强土壤有机碳过程与状态的定量化、土壤有机碳分解对环境因子的敏感性、氮沉降对土壤有机碳的影响、土壤有机碳对气候变率的响应及其反馈作用，以及土壤有机碳动态的综合模拟 5个方面的研究，为准确评估陆地碳收支提供依据。     

Perceptions of environmental change in Moorea,French Polynesia: the importance of temporal,spatial, and scalar contexts

Pacific Islands are considered among the most vulnerable geographies and societies to the effects of climate change and variability (CCV). This study addresses the mismatch between global climate change narratives and local perceptions of environmental change in Moorea, French Polynesia. This study builds on CCV risk perception and adaptation research by analyzing how temporal and historical socio-economic, cultural, political, and ecological contexts shape local perceptions of environmental change among a sample of environmental stakeholders in Moorea. The data were collected prior to the widespread global narrative and social amplification of climate change risk and its particular impact on islands. As such, they offer an important portrait of environmental perceptions in French Polynesia prior to the influence of a circumscribed climate change narrative, which has since come to shape government and NGO responses to environmental change in the Pacific Island Countries and Territories. The data presented in this paper illustrate that perceptions of drivers and effects of environmental change and risk in Moorea are embedded in larger social processes of political economy and ecology, particularly related to contemporary environmental politics, contextualized within the histories of colonialism and tourism-led economic development. Integrating the complexity of local environmental risk perceptions into CCV policy will help to avoid maladaptation, social movements against CCV planning, and may help maximize government and donor investments.     

Sea Level Rise and Its Risk Management

Sea level rise is among the most severe societal consequences of anthropogenic climate change. Significant advance has been achieved in recent years in the study of future sea level rise and its risk management practice: ①Sea level rise is considered as a kind of hazard,its future plausible scenarios and their probabilities are necessary to be predicted and estimated,and the upper limit with very low probability and high consequences should be emphasized. For this purpose,a complete probability distribution framework has been developed to predict the scenarios and probabilities of future sea level rise with Representative Concentration Pathways (RCPs) and the Shared Socioeconomic Pathways (SSPs) in recent years. ② For a high emissions scenario,it was found that Antarctic Ice Sheet might make a contribution to Global Mean Sea Level (GMSL) rise as high as 78150 cm (mean value 114 cm) by 2100. For the same scenario,the IPCC Fifth Assessment Report gave an Antarctic contribution of only -8+14 cm (mean value 4 cm). ③ Recent studies recommended a revised worst-case (Extreme) GMSL rise scenario of 2.5 m from previous 2.0 m by 2100. It is recognized that GMSL rise will not stop at 2100; rather,it will continue to rise for centuries afterwards,but the degree of uncertainty related to sea level rise will increase. ④ Approaches of combining the upper-bound scenario and a central estimate or mid-range scenario, Adaptation Pathways and robust decision-making are developed to provide a set of long-term planning envelope. These decision-making methods are used widely in coastal risk management related to future sea level rise. Sea level rise and its risk management need to enhance monitoring,analysis and simulation to predict the global,regional and local seal level rise scenarios and the probabilities with different time scales,reduce the estimate uncertainty, assess its upper limits, and enhance decision methods and their application under deep uncertain, in order to meet the needs of climate change adaptation planning,decision-making and long-term risk management in coastal regions.     

Global sensitivity analysis through polynomial chaos expansion of a basin-scale geochemical compaction model

We present a model-driven uncertainty quantification methodology based on sparse grid sampling techniques in the context of a generalized polynomial chaos expansion (GPCE) approximation of a basin-scale geochemical evolution scenario. The approach is illustrated through a one-dimensional example involving the process of quartz cementation in sandstones and the resulting effects on the dynamics of the vertical distribution of porosity, pressure, and temperature. The proposed theoretical framework and computational tools allow performing an efficient and accurate global sensitivity analysis (GSA) of the system states (i.e., porosity, temperature, pressure, and fluxes) in the presence of uncertain key mechanical and geochemical model parameters as well as boundary conditions. GSA is grounded on the use of the variance-based Sobol indices. These allow discriminating the relative weights of uncertain quantities on the global model variance and can be computed through the GPCE of the model response. Evaluation of the GPCE of the model response is performed through the implementation of a sparse grid approximation technique in the space of the selected uncertain quantities. GPCE is then be employed as a surrogate model of the system states to quantify uncertainty propagation through the model in terms of the probability distribution (and its statistical moments) of target system states.     

The preventive destruction of a hazardous asteroid

One means of countering a hazardous asteroid is discussed: destruction of the object using a nuclear charge. Explosion of such an asteroid shortly before its predicted collision would have catastrophic consequences, with numerous highly radioactive fragments falling onto the Earth. The possibility of exploding the asteroid several years before its impact is also considered. Such an approach is made feasible because the vast majority of hazardous objects pass by the Earth several times before colliding with it. Computations show that, in the 10 years following the explosion, only a negligible number of fragments fall onto the Earth, whose radioactivity has substantially reduced during this time. In most cases, none of these fragments collides with the Earth. Thus, this proposed method for eliminating a threat from space is reasonable in at least two cases: when it is not possible to undergo a soft removal of the object from the collisional path, and to destroy objects that are continually returning to near-Earth space and require multiple removals from hazardous orbits.     

Catastrophe bonds and financial risk: Securing capital and rule through contingency

This paper uses the example of catastrophe bonds to investigate how exposures to geophysical, biological, and meteorological catastrophic events are constituted as securitizable and exchangeable financial risks in the insurance-linked securities (ILS) market. It discusses the techniques of catastrophe modeling as a pivotal mobile methodology for the calculation and creation of contingent assets out of the fabric of insured environmental and financial vulnerabilities. Catastrophe models are shown to enable economic exchange of contingent futures belonging to ontologically and geographically disparate orders. Pension funds are then introduced to illustrate how biological lives and retirement savings have become deeply entangled in the creation and extension of the ILS market. Pension funds are both major institutional investors in catastrophe bonds and also the principal sellers of “longevity risk” posed by pensioners. The extent to which labor both profits from and embodies securitized insurance risks illustrates the growing importance and ambivalence of contingency as a modality of accumulation and rule.     

洪涝灾害风险评估与分区研究进展

在全球气候变化和城市化进程不断加快的背景下,城市洪涝灾害频发,造成严重的经济损失和人员伤亡问题。对近年来中国典型城市洪涝灾害进行系统整理介绍,说明洪涝灾害带来的人员伤亡和经济损失巨大。风险评估作为一种非工程性防洪措施,是城市洪涝风险管理的首要工作,精确、高效的把握洪灾过程等特征可以为防灾减灾工作提供科学依据。对城市洪涝风险评估与分区的概念和内容进行系统梳理,常用的风险评估方法有数理统计法、不确定性分析法、遥感影像评估法、指标体系评估法、情景模拟评估法；风险分区常用方法有阈值法、经验公式法和物理机制法。论述了城市洪涝风险评估与分区常用方法的应用范围、优缺点及其发展前景。     

全球变化及其相关科学概念的发展与比较

在回顾全球变化科学产生和发展历史的基础上,针对当前全球变化、全球气候变化、全球环境变化、地球系统科学在概念和内涵上存在混淆的情况,就全球变化等概念的内涵、产生的过程及其联系进行了综述、分析和比较。提出全球变化是指对人类现在和未来生存与发展有重要的直接或潜在影响、由自然因素或人类因素驱动在全球范围内所发生的地球环境的变化,或与全球环境有重要关联的区域环境的变化。气候变化和全球环境变化的研究范畴包含在全球变化之中,但又各有其关注领域和交叉部分;而地球系统科学是解决全球变化问题的科学理念、思维方式和解决方案。]     

Quantitative risk assessment of landslides with direct simulation of pre-failure to post-failure behaviors

Most previous studies on the quantitative risk assessment (QRA) of landslides focused on the probability of slope failure at the pre-failure stage and adopted empirical models for consequence analysis. The conventional approaches simplify the relationship between the pre-failure state and the post-failure behavior and cannot reasonably account for the effects of uncertainty on the entire landslide process. In this paper, an efficient QRA method that involves the direct simulation of the entire landslide process is proposed. A QRA formula that considers the probability of only those landslides that can impact the element at risk is used. The coupled Eulerian–Lagrangian method is used to simulate the entire landslide process and to identify slopes that can impact the element at risk and determine the failure consequences. The subset simulation method is adopted to efficiently estimate the probability of landslide impact, and parameter uncertainty is considered. Two case histories of landslides are investigated. First, the 2011 Baqiao loess landslide in Xi’an, China, is investigated, and the results of the proposed method are compared with those of the conventional approaches. Second, the proposed method is applied to assess the risk of the 2015 Ganjingzi landslide in the Three Gorges Reservoir. The effects of the risk mitigation works are also discussed.