Information structuring and risk-based inspection for the marine oil pipelines

The proposed work is incorporated into the research theme concerning the maintenance and inspection of sensitive facilities in production systems. It is essential to promote the methodological deployment of inspection techniques to ensure the good functioning of services provided by complex production systems as well as their different components. We use a risk-based inspection methodology offering an organized analysis with knowledge sharing for collaborative possibilities in a multidisciplinary context and it consists of the following steps: data acquisition and information collection, failure analysis (probability and consequences), risk assessment, inspection plan, mitigation and revaluation. The application of this methodology can improve the maintenance management strategies of industrial companies. The inspection department is able to forecast its potential failure, root causes and impacts on the safe operation of the considered production system, based on a reliable inventory of existing situations and review options for continuous improvement in maintenance management. In particular, we addressed the application of a Risk-Based Inspection (RBI) methodology in the French petroleum company with operations on the west coast of central and southern Africa. The incorporation of expert knowledge into risk assessment is helping to find the best preventive plan for pipeline inspection in the case study.     

Uncertainty in dam safety risk analysis

The character and importance of uncertainty in dam safety risk analysis drives how risk assessments are used in practice. The current interpretation of uncertainty is that, in addition to the aleatory risk which arises from presumed uncertainty in the world, it comprises the epistemic aspects of irresolution in a model or forecast, specifically model and parameter uncertainty. This is true in part but it is not all there is to uncertainty in risk analysis. The physics of hazards and of failure may be poorly understood, which goes beyond uncertainty in its conventional sense. There may be alternative scenarios of future conditions, for example non-stationarity in the environment, which cannot easily be forecast. There may also be deep uncertainties of the type associated with climate change. These are situations in which analysts do not know or do not agree on the system characterisation relating actions to consequences or on the probability distributions for key parameters. All of these facets are part of the uncertainty in risk analysis with which we must deal.     

The Swedish Geotechnical Society’s methodology for risk management: a tool for engineers in their everyday work

The Swedish Geotechnical Society has adopted a general methodology for risk management in geotechnical engineering projects to reduce the costs related to negative outcomes of geotechnical risks. This technical note highlights the main features of the methodology and strives to inspire the international geotechnical community to apply sensible risk management methods. In the authors’ opinion, a successful geotechnical risk management needs to be structured, be tailored to the project, and permeate the engineers’ everyday work. Then, sufficient quality can be achieved in the project with larger probability.     

Landslide susceptibility zonation method based on C5.0 decision tree and K-means cluster algorithms to improve the efficiency of risk management

Machine learning algorithms are an important measure with which to perform landslide susceptibility assessments,but most studies use GIS-based classification methods to conduct susceptibility zonation.This study presents a machine learning approach based on the C5.0 decision tree(DT)model and the K-means cluster algorithm to produce a regional landslide susceptibility map.Yanchang County,a typical landslide-prone area located in northwestern China,was taken as the area of interest to introduce the proposed application procedure.A landslide inventory containing 82 landslides was prepared and subse-quently randomly partitioned into two subsets:training data(70％landslide pixels)and validation data(30％landslide pixels).Fourteen landslide influencing factors were considered in the input dataset and were used to calculate the landslide occurrence probability based on the C5.0 decision tree model.Susceptibility zonation was implemented according to the cut-off values calculated by the K-means clus-ter algorithm.The validation results of the model performance analysis showed that the AUC(area under the receiver operating characteristic(ROC)curve)of the proposed model was the highest,reaching 0.88,compared with traditional models(support vector machine(SVM)=0.85,Bayesian network(BN)=0.81,frequency ratio(FR)=0.75,weight of evidence(WOE)=0.76).The landslide frequency ratio and fre-quency density of the high susceptibility zones were 6.76/km2 and 0.88/km2,respectively,which were much higher than those of the low susceptibility zones.The top 20％interval of landslide occurrence probability contained 89％of the historical landslides but only accounted for 10.3％of the total area.Our results indicate that the distribution of high susceptibility zones was more focused without contain-ing more"stable"pixels.Therefore,the obtained susceptibility map is suitable for application to landslide risk management practices.     

中国冰冻圈变化的适应研究：进展与展望

冰冻圈变化的适应研究是冰冻圈科学领域的新兴研究方向,是当今自然科学与社会科学交叉融合跨学科集成研究的典型代表。起步于2007年的中国冰冻圈变化适应研究,经历了早期的探索,研究重点由评价脆弱性发展为量化冰冻圈变化的影响,形成以影响/风险—脆弱性—适应全链条的完善的研究体系,研究方法突破传统的指标体系赋权法的不足,初步实现了定量化,有机结合影响/风险、脆弱性、适应三方面的研究结果,使冰冻圈变化的适应措施由偏重宏观性、普适性开始转向更有针对性。未来中国冰冻圈变化的适应研究应拓展、完善和深化现有的理论体系,构建冰冻圈与社会经济耦合模型,科学量化冰冻圈全要素变化的影响,建立不同利益相关者与科学家共同参与的研究新模式,科学有效应对与适应冰冻圈变化及其影响。     

Flood insurance arrangements in the European Union for future flood risk under climate and socioeconomic change

Flood risk will increase in many areas around the world due to climate change and increase in economic exposure. This implies that adequate flood insurance schemes are needed to adapt to increasing flood risk and to minimise welfare losses for households in flood-prone areas. Flood insurance markets may need reform to offer sufficient and affordable financial protection and incentives for risk reduction. Here, we present the results of a study that aims to evaluate the ability of flood insurance arrangements in Europe to cope with trends in flood risk, using criteria that encompass common elements of the policy debate on flood insurance reform. We show that the average risk-based flood insurance premium could double between 2015 and 2055 in the absence of more risk reduction by households exposed to flooding. We show that part of the expected future increase in flood risk could be limited by flood insurance mechanisms that better incentivise risk reduction by policyholders, which lowers vulnerability. The affordability of flood insurance can be improved by introducing the key features of public-private partnerships (PPPs), which include public reinsurance, limited premium cross-subsidisation between low- and high-risk households, and incentives for policyholder-level risk reduction. These findings were evaluated in a comprehensive sensitivity analysis and support ongoing reforms in Europe and abroad that move towards risk-based premiums and link insurance with risk reduction, strengthen purchase requirements, and engage in multi-stakeholder partnerships.     

内蒙古东南部暴雨洪涝灾害风险评估与区划——以通辽市为例

文章选取通辽市各气象站点气象数据、基础地理信息数据、历史灾情数据、第二次土地调查数据及相关社会经济等统计数据,基于自然灾害风险原理,利用数理统计、层次分析法及空间叠加分析等方法,提出了通辽市暴雨洪涝灾害风险评价指标体系,得到通辽市暴雨洪涝灾害风险评估空间分布图。结果表明:高风险区主要分布在通辽市北部山区、中东部地区及偏南部地区,包括扎鲁特旗鲁北镇、科尔沁区、科左中旗东南部及库伦旗东南部;而科左后旗大部地区易形成由短时强降水引发的洪涝,为次高风险区;低风险区及次低风险区主要分布在通辽市中部、西南部地区,包括开鲁县、奈曼旗北部、科左中旗西部。     

东北三省城乡协调发展格局及影响因素

以东北三省36个地区为研究对象,系统构建了城乡协调的指标体系,采用基尼系数、空间自相关和空间回归等方法探讨了2005年、2010年和2015年东北三省城乡协调的空间格局和影响机制。研究表明:① 东北三省城乡协调度的区域差异不断扩大且具有明显的空间集聚特征,但集聚程度趋于减弱。② 不同地区城乡协调水平变化各异。研究期内,大连市和锦州市一直处于高水平城乡协调状态,朝阳市长期处于低水平城乡协调状态。鹤岗市和七台河市城乡协调度位次上升最明显,哈尔滨市和辽源市城乡协调度位次下降最显著。③ 从空间格局来看,中级城乡协调区增多且向北移动,初级城乡协调区减少且向中部集中,“南北高,中间低”的城乡协调格局基本形成。与此同时,城乡协调的冷热点均不断收缩,空间极化效应趋于减弱。④ 城镇化和农业规模化经营是促进东北城乡协调发展的主要力量,工业化并未显著促进东北城乡协调发展且与城乡协调发展负相关,农业现代化经营对城乡协调发展有正向作用,交通因素在近些年的促进作用逐渐凸显,经济发展水平与信息化水平对东北城乡协调发展的作用还不明显。     

Return period and risk calculations for ocean wave energy applications

The statistical behavior of wave energy at a site strongly depends on the wave characteristics. Wave energy converters fail to produce energy when there are no sufficiently available wave heights. Hence, evaluation of return periods and risk values of the minimum wave height becomes important for wave energy studies. A time index representing the minimum wave height is proposed here for ocean wave applications. Persistence plays a significant role in the calculation of return period and risk. Although ignoring the serial independence makes calculations easy, it leads to overestimations of the real status. In this paper, return periods and risk values are compared with each other by taking into consideration independent and dependent situations. Application of the study is achieved for the stations located in the Pacific Ocean and Gulf of Mexico.     

The restoration of fishing services and the conveyance of risk information in the Southern California Bight

Southern California's marine areas are heavily contaminated with dichloro-diphenyl-trichloroethane (DDT) and polychlorinated-biphenyls (PCBs), and fish consumption advisories (FCAs) have been issued throughout the region. Between 2002 and 2003, the Montrose Angler Survey, a large-scale survey of subsistence anglers, was developed and implemented on site in Orange and Los Angeles counties. This survey was intended to assist natural resource trustees in the development of restoration programs that will address injuries to natural resources and restore lost economic services for anglers, but the data were never fully analyzed. The trustees have shown a clear preference for ecological restoration programs that may take years to improve fishing services. In contrast, this analysis, which includes a random-parameter fishing site choice model, demonstrates that simple, inexpensive programs such as better signage to warn of FCAs and transportation to clean sites have the potential to yield substantial benefits quickly. This paper also focuses on how different ethnic minority groups are affected by FCAs, and determines how best to communicate risk information and change fishing behavior through outreach programs.