Preliminary assessment of CO2 transport and storage costs of promising source–sink matching scenarios in Guangdong province,China

Guangdong is the most economically developed province in China, which is a large CO₂ emitter and hence is faced with severe carbon reduction pressures. In this paper, a cost assessment methodology based on scenario analysis is presented. A CO₂ source and sink database was built at Guangdong after detailed investigations on the point sources and sedimentary basins. Fifteen transport and five storage scenarios were defined and studied, respectively. Cost estimates based on these scenarios show that during its lifetime, the costs of both transport and storage depend on the amount of CO₂ processed. More CO₂ being processed will bring down the unit costs of both transport and storage. However, it was observed that there is a cost inflection point between the storage amount of 35.2 and 52.8 Mt/year, which means that as the storage amount increases, the storage cost will first decrease and then increase. Source region S1 in Guangdong has been recommended for an early chance of CO₂ storage. Preliminary cost comparisons have shown that the results presented in this study are reasonable, but to improve the cost assessment accuracy of offshore CO₂ storage, a methodology based on a CO₂ storage design that can integrate local prices needs to be further developed.     

Human alteration of groundwater–surface water interactions (Sagittario River,Central Italy): implication for flow regime,contaminant fate and invertebrate response

Many rivers worldwide are undergoing severe man-induced alterations which are reflected also in changes of the degree of connectivity between surface waters and groundwater. Pollution, irrigation withdrawal, alteration of freshwater flows, road construction, surface water diversion, soil erosion in agriculture, deforestation and dam building have led to some irreversible species losses and severe changes in community composition of freshwater ecosystems. Taking into account the impact of damming and flow diversion on natural river discharge, the present study is aimed at (i) evaluating the effects of anthropogenic changes on groundwater/surface water interactions; (ii) analyzing the fate of nitrogenous pollutants at the floodplain scale; and (iii) describing the overall response of invertebrate assemblages to such changes. Hydrogeological, geochemical and isotopic data revealed short- and long-term changes in hydrology, allowing the assessment of the hydrogeological setting and the evaluation of potential contamination by nitrogen compounds. Water isotopes allowed distinguishing a shallow aquifer locally fed by zenithal recharge and river losses, and a deeper aquifer/aquitard system fed by surrounding carbonate aquifers. This system was found to retain ammonium and, through the shallow aquifer, release it in surface running waters via the hyporheic zone of the riverbed. All these factors influence river ecosystem health. As many environmental drivers entered in action offering a multiple-component artificial environment, a clear relationship between river flow alteration and benthic and hyporheic invertebrate diversity was not found, being species response driven by the combination of three main stressors: ammonium pollution, man-induced changes in river morphology and altered discharge regime.     

Evaluating groundwater resource of an urban alluvial area through the development of a numerical model

As established in the European Water Framework Directive, the development of groundwater numerical models is fundamental for adopting water management plans aimed at preserving the water resource and reducing environmental risks. In this paper, authors present a methodology for the estimation of groundwater resource of an alluvial valley, in an urban area characterized by a complex hydrostratigraphic setting and scarcity of hydrogeological data; the study area is the urban and sub-urban area of Rome (Italy). A previous, elaborated hydrostratigraphic model set the base for the development of 3D, steady state, sub-basin scale numerical model, implemented by the finite-difference code MODFLOW 2000^®; the water system components were derived by elaboration of available data. The alluvial aquifer of the Tiber River Valley, which runs in the middle of the City in a NNW–SE direction, has been analyzed in detail, since it is covered by a densely populated area hosting most of Rome’s historical heritage, and it is characterized by low quality geotechnical parameters. Results suggest that in areas with high hydrostratigraphic complexity and scarcity of hydrogeological data, a sub-basin scale, and steady-state numerical model can be very helpful to verify the conceptual model and reduce the uncertainty on the water budget components. The proposed steady-state model constitutes the base for future applications of transient state and local scale models, required for sustainable water management.     

Web Service for extracting stream networks from DEM data

This paper describes the implementation of a morphology based algorithm for extracting stream networks from data as a Web Service within the framework of GeoBrain, an open, interoperable, distributed, standard-compliant, multi-tier web-based geospatial information services and knowledge building system. Unlike standard out-of-the-box GIS software, which uses the flow direction based algorithm and often produces streams that are spatially uniform, streams extracted with this Web Service correctly reflect spatial variability in dissection patterns. In addition, this Web Service is free and can be accessed from anywhere provided that there is an Internet connection and a standard Web browser.     

生物降解作用对烷基萘异构体分布的影响及其控制因素

在受到溢油污染的海滩上采集不同时间序列的石油样品,对芳烃组分烷基萘中的三甲基萘和四甲基萘各异构体的生物降解过程响应进行了详细分析。研究揭示,三甲基萘比四甲基萘更易被生物降解,其中1,2,7-三甲基萘、2,3,6-三甲基萘、2,3,6,7-四甲基萘、1,2,3,7-四甲基萘和1,3,5,7-四甲基萘等异构体具有相对较高的生物降解效率,与最近 Ostojié等利用理论模型计算所给出的降解序列十分一致,进一步证实了烷基萘在表生环境中的降解主要受控于异构体萘环上取代基的数量和位置。研究结果对于表生环境中萘系物类多环芳烃污染的生物修复评价具有重要指导意义。     

Coastal vulnerability to wave storms of Sele littoral plain (southern Italy)

This paper presents a new method for coastal vulnerability assessment (CVA), which relies upon three indicators: run-up distance (as a measurement of coastal inundation), beach retreat (as a measurement of potential erosion), and beach erosion rate (obtained through the shoreline positions in different periods). The coastal vulnerability analysis of Sele Coastal Plain to storm impacts is examined along a number of beach profiles realized between 2008 and 2009. This particular study area has been selected due to its low-lying topography and high erosion propensity. Results are given in terms of an impact index, performed by combining the response due to coastal inundation, storm erosion, and beach erosion rate. This analysis is implemented on the basis of morphosedimentary characteristics of the beach, wave climate evaluation, and examination of multitemporal aerial photographs and topographic maps. The analysis of the final results evidences different coastal responses as a function of the beach width and slope, which in turn depend on the local anthropization level. The comparison of this method with a Coastal Vulnerability Index method evidences the better attitude of CVA index to take into account the different beach features to explain the experienced damages in specific stretches of the coastline considered.     

Multi-risk governance for natural hazards in Naples and Guadeloupe

Technical and institutional capacities are strongly related and must be jointly developed to guarantee effective natural risk governance. Indeed, the available technical solutions and decision support tools influence the development of institutional frameworks and disaster policies. This paper analyses technical and institutional capacities, by providing a comparative evaluation of governance systems in Italy and France. The focus is on two case studies: Naples and Guadeloupe. Both areas are exposed to multiple hazards, including earthquakes, volcanic eruptions, landslides, floods, tsunamis, fires, cyclones, and marine inundations Cascade and conjoint effects such as seismic swarms triggered by volcanic activity have also been taken into account. The research design is based on a documentary analysis of laws and policy documents informed by semi-structured interviews and focus groups with stakeholders at the local level. This leads to the identification of three sets of governance characteristics that cover the key issues of: (1) stakeholders and governance level; (2) decision support tools and mitigation measures; and (3) stakeholder cooperation and communication. The results provide an overview of the similarities and differences as well as the strengths and weaknesses of the governance systems across risks. Both case studies have developed adequate decision support tools for most of the hazards of concern. Warning systems, and the assessment of hazards and exposure are the main strengths. While technical/scientific capacities are very well developed, the main weaknesses involve the interagency communication and cooperation, and the use and dissemination of scientific knowledge when developing policies and practices. The consequences for multi-risk governance are outlined in the discussion.     

基于互信息量与BP神经网络的中长期径流预报方法研究

针对中长期径流预报因子的选择问题,采用互信息量方法筛选预报模型输入因子,在BP神经网络模型中,分别用均方误差和互信息量作为目标函数,衡量因子复合相关关系,优化选择最终预报因子并应用于碧流河汛期径流预报中。结果表明,基于互信息量筛选的预报因子与BP神经网络模型相结合,可有效识别多个预报因子与预报量间的复合相关性,对中长期径流预报因子的选择有很好参考价值。     

麻江古油藏油源识别与油气运聚分析：来自油气地球化学的证据

充分考虑热演化过程中烃源岩干酪根、族组分、固体沥青及正构烷烃碳同位素相互关系及变化规律,通过地球化学分析并结合前人碳同位素及芳烃标志物研究进行综合分析,结果表明古油藏各区域储层早期均存在下寒武统黑色泥岩来源,后期来源有较大差别,麻江古背斜以南各地沥青均不同程度与中寒武统都柳江组有关,北凯里液态原油及油苗为五峰组及龙马溪组印支期成藏产物,其保存环境为储层早期成岩过程中形成的独立封闭系统。在油源识别的基础上,结合构造地质背景、油气成藏条件及流体活动规律分析,认为黔南坳陷及邻区下寒武统、都柳江组、五峰组及龙马溪组烃源岩的分布控制了该区油气富集规律,黔南海西期断裂系统与加里东运动形成的不整合面构成不同期次油气运聚的输导系统,海西期形成的一系列正断裂是麻江古油藏成藏的关键。     

湖南锡田岩体的岩浆混合成因:岩相学､岩石地球化学和U-Pb 年龄证据

南岭中段的锡田岩体燕山期岩石以斑状黑云母二长花岗岩为主,岩体中广泛发育暗色微粒包体?暗色微粒包体为岩浆结构,大多数具有塑性外形,发育淬冷边?反向脉,存在多种不平衡结构和矿物组合,如钾长石环斑?石英眼斑?针状磷灰石等,显示岩浆混合特征?岩石地球化学方面,暗色微粒包体具有比寄主岩贫硅?贫碱,富K?Fe?Mg?Ca?Ti 特征;暗色微粒包体及寄主岩富集轻稀土元素(LREE/HREE=2.6~8.8),具有中-强的铕负异常(δEu=0.09~0.74)以及具有相似的稀土元素配分曲线和微量元素蛛网图;在主要氧化物含量Harker 图解中投点多呈直线变异趋势,反映了两者具有密切的亲缘关系,利用共分母和不共分母图解进行判别,暗色微粒包体与寄主岩具岩浆混合特征,在MgO-TFeO判别图解中也指示包体为岩浆混合成因?上述岩相学和元素地球化学特征表明暗色微粒包体是基性岩浆侵入到酸性岩浆中淬冷形成的,指示锡田岩体存在两种岩浆的混合作用?通过LA-ICP-MS锆石U-Pb 定年,得到寄主岩形成年龄(150.04±0.52)Ma,暗色包体形成年龄(145.09±0.63)Ma,二者年龄在测试误差范围内一致,显示岩浆混合作用发生的时间大致为晚侏罗世?