多参量联合分析的地震空间探测异常研究进展

卫星对地观测技术是全球范围内实时监测孕震区地震活动和震后应急救援的有力工具。过去的几十年里,不同种类的卫星观测数据被应用于地震遥感异常探测领域中,并逐渐开展了从单个震例分析,到普遍规律探索,再到内部机理研究的多方面探讨。但由于地球系统的复杂性和孕震过程的不确定性,地震遥感异常研究仍充满困难和挑战。本文利用文献计量分析方法,探究了现今国内外地震遥感异常研究的关注热点和趋势方向,认为目前对于地震遥感异常的研究已由单一参量发展为多参量联合分析阶段;通过3个前沿研究案例分析了常用的综合分析参量与异常分析方法,以及多参量之间的时空同步性关系,表明多参量遥感异常的结合研究和交叉验证是地震遥感异常研究中的重要手段,可以在未来地震前兆研究中发挥重要作用。      

Advancing process‐based watershed hydrological research using near‐surface geophysics: a vision for,and review of,electrical and magnetic geophysical methods

We want to develop a dialogue between geophysicists and hydrologists interested in synergistically advancing process based watershed research. We identify recent advances in geophysical instrumentation, and provide a vision for the use of electrical and magnetic geophysical instrumentation in watershed scale hydrology. The focus of the paper is to identify instrumentation that could significantly advance this vision for geophysics and hydrology during the next 3–5 years. We acknowledge that this is one of a number of possible ways forward and seek only to offer a relatively narrow and achievable vision. The vision focuses on the measurement of geological structure and identification of flow paths using electrical and magnetic methods. The paper identifies instruments, provides examples of their use, and describes how synergy between measurement and modelling could be achieved. Of specific interest are the airborne systems that can cover large areas and are appropriate for watershed studies. Although airborne geophysics has been around for some time, only in the last few years have systems designed exclusively for hydrological applications begun to emerge. These systems, such as airborne electromagnetic (EM) and transient electromagnetic (TEM), could revolutionize hydrogeological interpretations. Our vision centers on developing nested and cross scale electrical and magnetic measurements that can be used to construct a three‐dimensional (3D) electrical or magnetic model of the subsurface in watersheds. The methodological framework assumes a ‘top down’ approach using airborne methods to identify the large scale, dominant architecture of the subsurface. We recognize that the integration of geophysical measurement methods, and data, into watershed process characterization and modelling can only be achieved through dialogue. Especially, through the development of partnerships between geophysicists and hydrologists, partnerships that explore how the application of geophysics can answer critical hydrological science questions, and conversely provide an understanding of the limitations of geophysical measurements and interpretation. Copyright © 2008 John Wiley & Sons, Ltd.     

地球系统模拟和混沌时间序列

地球系统是非线性的系统.为了模拟地球系统,我们就必须了解非线性科学的最新进展.本文从非线性科学角度论述了地球系统模拟中的几个关键问题,如尺度是分层次的,不同尺度之间存在着相似性及标度律,同时也存在差异性及非均匀性.为此还介绍了一些概念:吸引子、分维、信息和熵等.最后本文还说明如何从地球系统中所观测到的时间序列取得地球系统模拟所需要的信息.     

流域综合管理方法与技术

流域作为一个具有明确边界的地理单元,流域以水为纽带,将上、中、下游组成一个普遍具有因果联系的复合生态系统,是实现资源和环境管理的最佳单元.流域综合管理已经被认为是实现资源利用和环境保护相协调的最佳途径.然而,由于流域综合管理涉及多学科,多部门,内容非常广泛.近年的流域管理还主要停留在一个目标.本文在流域模拟管理研究及实践的相关经验基础上,系统地讨论了流域综合管理实施方法、关键技术以及主要技术问题.     

Progress and perspective on frontiers of geobiology

Geobiology is a new discipline on the crossing interface between earth science and life science,and aims to understand the interaction and co-evolution between organisms and environments.On the basis of the latest international achievements,the new data presented in the Beijing geobiology forum sponsored by Chinese Academy of Sciences in 2013,and the papers in this special issue,here we present an overview of the progress and perspectives on three important frontiers,including geobiology of the critical periods in Earth history,geomicrobes and their responses and feedbacks to global environmental changes,and geobiology in extreme environments.Knowledge is greatly improved about the close relationship of some significant biotic events such as origin,radiation,extinction,and recovery of organisms with the deep Earth processes and the resultant environmental processes among oceans,land,and atmosphere in the critical periods,although the specific dynamics of the co-evolution between ancient life and paleoenvironments is still largely unknown.A variety of geomicrobial functional groups were found to respond sensitively to paleoenvironmental changes,which enable the establishment of proxies for paleoenvironmental reconstruction,and to play active roles on the Earth environmental changes via elemental biogeochemical cycles and mineral bio-transformations,but to be deciphered are the mechanisms of these functional groups that change paleoenvironmental conditions.Microbes of potential geobiology significance were found and isolated from some extreme environments with their biological properties partly understood,but little is known about their geobiological functions to change Earth environments.The biotic processes to alter or modify the environments are thus proposed to be the very issue geobiology aims to decipher in the future.Geobiology will greatly extend the temporal and spatial scope of biotic research on Earth and beyond.It has great potential of application in the domains of resource exploration and global change.To achieve these aims needs coordinative multidisciplinary studies concerning geomicrobiology and related themes,database and modeling of biogeochemical cycles,typical geological environments,and coupling of biological,physical,and chemical processes.     

地球自转速率变化及其与地球物理现象关系研究的进展

作为地球的基本运动形式之一的地球自转变化表征着地球的整体运动状态和地球系统各圈层之间的相互作用过程,其变化形式非常复杂．研究表明,地球自转速率的变化与众多地球物理现象有密切联系,与地震活动、EN-SO事件等重大自然灾害存在一定的相关性．因此,对地球自转速率变化及其与地球物理现象之间关系的研究长期以来就受到天文学家、地球科学家和从事灾害研究领域专家的重视．本文主要介绍了该研究领域近年来的研究进展,并认为在此基础上开展更深入的研究对天文学和地球科学的发展都是有意义的．     

The oxygen cycle and a habitable Earth

As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating the global oxygen cycle provides valuable information on the evolution of the Earth system, the habitability of our planet in the geologic past, and the future of human life. Numerous investigations have expanded our knowledge of the oxygen cycle in the fields of geology,geochemistry, geobiology, and atmospheric science. However, these studies were conducted separately, which has led to onesided understandings of this critical scientific issue and an incomplete synthesis of the interactions between the different spheres of the Earth system. This review presents a five-sphere coupled model of the Earth system and clarifies the core position of the oxygen cycle in Earth system science. Based on previous research, this review comprehensively summarizes the evolution of the oxygen cycle in geological time, with a special focus on the Great Oxidation Event(GOE) and the mass extinctions, as well as the possible connections between the oxygen content and biological evolution. The possible links between the oxygen cycle and biodiversity in geologic history have profound implications for exploring the habitability of Earth in history and guiding the future of humanity. Since the Anthropocene, anthropogenic activities have gradually steered the Earth system away from its established trajectory and had a powerful impact on the oxygen cycle. The human-induced disturbance of the global oxygen cycle, if not controlled, could greatly reduce the habitability of our planet.     

Harmonizing models and observations: Data assimilation in Earth system science

Models and observations are two fundamental methodological approaches in Earth system science(ESS). They evolve collaboratively and enhance one another. However, neither of these two approaches is perfect, and they have incompatibilities due to their methodological differences. The emergence of data assimilation(DA) has enabled these two approaches to develop in conjunction and form a harmonic ESS methodology. As a result, DA has shown a fresh vitality and applicability in ESS. This paper reviews the application of DA in the main branches of ESS, traces the coordinated evolution of DA with the methodologies of rationalism and empiricism, analyzes the relationships of DA with estimation theory and cybernetics, summarizes the advances of DA in China, and presents an outlook on the challenges facing the development of a uniform DA for ESS. DA theories and methods will continue to evolve and provide an increasingly mature methodology for enhancing the understanding and prediction of Earth as a system.     

The Earth as an open system: Geological and geophysical consequences

In spite of numerous publications, in which the nonlinear and fractal nature of the Earth evolution is emphasized, until now, many processes in the solid Earth are considered in terms of the classical science of the closed equilibrium systems. The basic properties of the open dissipative nonlinear systems and their manifestation in all geospheres are discussed. Based on the ideas that the Earth is a nonlinear open system, special attention is given to the study of the problems of the earthquake mechanisms, their prediction, and the tectonophysical experiments. The reason for the awkward adoption of the new paradigm by the scientific community in the earth sciences is analyzed.     

Stormy geomorphology: geomorphic contributions in an age of climate extremes

The increasing frequency and/or severity of extreme climate events are becoming increasingly apparent over multi‐decadal timescales at the global scale, albeit with relatively low scientific confidence. At the regional scale, scientific confidence in the future trends of extreme event likelihood is stronger, although the trends are spatially variable. Confidence in these extreme climate risks is muddied by the confounding effects of internal landscape system dynamics and external forcing factors such as changes in land use and river and coastal engineering. Geomorphology is a critical discipline in disentangling climate change impacts from other controlling factors, thereby contributing to debates over societal adaptation to extreme events. We review four main geomorphic contributions to flood and storm science. First, we show how palaeogeomorphological and current process studies can extend the historical flood record while also unraveling the complex interactions between internal geomorphic dynamics, human impacts and changes in climate regimes. A key outcome will be improved quantification of flood probabilities and the hazard dimension of flood risk. Second, we present evidence showing how antecedent geomorphological and climate parameters can alter the risk and magnitude of landscape change caused by extreme events. Third, we show that geomorphic processes can both mediate and increase the geomorphological impacts of extreme events, influencing societal risk. Fourthly, we show the potential of managing flood and storm risk through the geomorphic system, both near‐term (next 50 years) and longer‐term. We recommend that key methods of managing flooding and erosion will be more effective if risk assessments include palaeodata, if geomorphological science is used to underpin nature‐based management approaches, and if land‐use management addresses changes in geomorphic process regimes that extreme events can trigger. We argue that adopting geomorphologically‐grounded adaptation strategies will enable society to develop more resilient, less vulnerable socio‐geomorphological systems fit for an age of climate extremes. © 2016 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.     

基于GeoMedia的考古探测综合解释系统

无损探测是考古研究的一种先进方法和手段,它是一种通过地球物理方法不用挖掘而直接探测地下遗迹、遗物的考古技术.目前地球探测技术拥有众多的方法和手段,不同方法和手段获得大量的不同尺度、不同格式的地球探测数据,为了更好管理和应用这些不同类型的庞杂的探测数据,并将探测结果与考古信息和历史记裁进行相互印证判断,我们利用Intergraph的GeoMedia GIS技术,以考古探测数据为基础建立了一套基于地球探测考古的数据存储、管理、分析以及多种方法综合解释的多功能地理信息系统.本文详述了其系统结构、实现流程,该系统被应用于国家科技攻关项目中,并且可推广应用.     

Substructuring of dynamical systems via the adaptive minimal control synthesis algorithm

In this paper we consider the concept of modelling dynamical systems using numerical–experimental substructuring. This type of modelling is applicable to large or complex systems, where some part of the system is difficult to model numerically. The substructured model is formed via the adaptive minimal control synthesis (MCS) algorithm. The aim of this paper is to demonstrate that substructuring can be carried out in real time, using the MCS algorithm. Thus, we reformulate the MCS algorithm into a substructuring form. We introduce the concepts of a transfer system, and carry out numerical simulations of the substructuring process using a coupled three mass example. These simulations are compared with direct simulations of a three mass system. In addition we consider the stability of the substructuring algorithm, which we discuss in detail for a class of second‐order transfer systems. A numerical–experimental system is considered, using a small‐scale experimental system, for which the substructuring algorithm is implemented in real time. Finally we discuss these results, with particular reference to the future application of this method to modelling large‐scale structures subject to earthquake excitation. Copyright © 2001 John Wiley & Sons, Ltd.     

Integrative ecology in the era of big data——From observation to prediction

Most ecological and environmental issues faced by human society can only be solved at the ecosystem, watershed,regional and even global scale. Thus, ecological research is developing rapidly towards macro-scale studies. With the rapid development of observational networks and information technology, the spaceborne-aircraft-ground based observation system is becoming an important feature of ecosystem monitoring in the new era. With the gradual formation of the global new-generation observational systems and the rapid expansion of massive multi-source heterogeneous data, ecology has entered the era of big data, big science, and big theory. How to integrate ecological big data, discover valuable ecological laws and mechanisms, and further expand them to solve eco-environmental issues that closely relate to human development are the major opportunities and challenges in this field. In this paper, we systematically summarized the research progresses in ecological big data, reviewed the opportunity and demand of integrative ecology, and further discussed the main approaches of ecological big data integration by using meta-analysis, data mining, and data-model fusion. Finally, we proposed the prospects and research directions of integrative ecology and suggested that future researches need to integrate big data into land models so as to improve the accuracy of ecological forecasting. It can be foreseen that under the background of global change and the rapid development of big data in the future, integrative ecology will be extensively applied and developed to serve the sustainable development of human society.     

不同尺度流域地表径流氮、磷浓度比较

选择太湖上游为研究对象,采集了1-400 km2不同尺度小流域产出径流TN、TP浓度实测数据,结合前期开展的地表坡面流人工暴雨实验监测结果,开展不同尺度流域水质监测对水体面源污染产出浓度估算影响的比较研究,探讨流域尺度之间入渗、汇流以及伴随的流域生态系统营养盐调节机制的差异．结果表明,流域监测尺度对土地利用面源污染产出浓度估算有较大影响．地表坡面流由于未经过流域汇流过程伴随的下渗滤过与吸附等过程,产出径流TN、TP浓度一般高于小流域．小流域林地生态系统具有较强的入渗机制、接近自然的生态沟谷汇流网络,对面源污染TN、TP有较强的削减作用．农业生态系统较弱的入渗机制、人工沟渠汇流网络对面源污染TN、TP的削减作用较弱．现代农业造成流域面源污染增加不仅仅是因为人类农业活动对流域局部土体及养分的改变,农业生态系统改变流域自然生态系统整体水文过程及营养盐调节机制也是面源污染增加的重要因素之一,恢复小尺度的生态沟谷网络系统对削减流域面源污染具有重要的意义．     

Not vegetation itself but mis-revegetation reduces water resources

Increasing greening of planet Earth to slow down the rise of atmospheric CO2 concentrations is certainly desirable;however, its consequences on water resources are less affirmative and thus are a matter of wide concern. China, as the largest and most successful country of the world in terms of artificial revegetation, is naturally the focus of the concerns and warnings. Based on previous studies, we analyzed the mechanism for the effects of climate and watershed characteristics on water resources,explained various hydrological results and phenomena, and considered the ways in which water consumption by artificial revegetation projects can be reduced. Moreover, some guidelines are suggested for artificial revegetation at watershed scale with consideration of water resource sustainability. The findings of this study highlight the need for more top-down approaches when studying the mechanism of "forest and water".     

湖泊流域生态系统演化对人类世研究的重要意义

人类世可能成为一个全新的地质时期,以描述人类活动对地球环境造成极为深远的影响,目前已被广泛讨论。湖泊及流域生态系统作为与人类社会最密切的地球单元之一,受到人类活动显著影响,相关研究成果能为理解人类世做出贡献。本文从湖泊流域生态系统和人类世本身特征为切入点,讨论了湖泊及流域生态系统演化对人类世研究的重要意义。我们认为,湖泊具有相对独立的整体,清晰的内部作用关系、完备的理论支持和时空数据支撑,能够为人类世地球各圈层交互作用提供研究框架。湖泊流域生态系统演化的稳态转换与地球环境进入新的地质时期具有诸多相似之处,相关研究成果能够更好地界定人类世开始时间、总体特征以及演变过程和机制。本文指出人类世湖泊及流域生态系统演化研究依然面临诸多挑战,并提出了对未来相关研究的展望。     

Comparing state-of the art near-surface models of a seismic test line from Saudi Arabia

We present a seismic Test Line, provided by Saudi Aramco for various research teams, to highlight a few major challenges in land data processing due to near‐surface anomalies. We discuss state‐of‐the‐art methods used to compensate for shallow distortions, including single‐layer, multilayer, plus/minus, refraction and tomostatics methods. They are a starting point for the new technologies presented in other papers, all dealing with the same challenging data described here. The difficulties on the Test Line are mostly due to the assumption of vertical raypaths, inherent in classical applications of near‐surface correction statics. Even the most detailed velocity/depth model presents difficulties, due to the compleX‐raypath. There is a need for methods which are based on more complex models andtheories.     

An Overview of Thunderstorm-Related Research on the Atmospheric Electric Field, Schumann Resonances, Sprites, and the Ionosphere at Sopron, Hungary

This paper gives a resume of the papers written in English which (a) describe some of the recording instruments in use at the Nagycenk Observatory (NCK) since the International Geophysical Year (IGY 1957–1958) and up to the present time, (b) summarise the most important and different types of observations associated with thunderstorms which have been made there, and (c) discuss their various geophysical interpretations. The paper describes the main results which have been obtained in four areas of thunderstorm associated atmospheric and geospace science within the context of Earth system science. These relate to the following parameters of atmospheric electricity: the vertical electric potential gradient just above the Earth’s surface and the air–Earth current as well as the point discharge current, Schumann resonance (SR) signals of the Earth-ionosphere cavity at 8, 14 and 20 Hz, transient luminous events (TLEs), and some aspects of the behaviour of the ionosphere. Deductions from these data sets are concerned with the global lightning activity and the conductivity of the air, with diurnal, seasonal, annual and long-term variations of the SR amplitudes and resonant frequencies in terms of migrating thunderstorm centres, with transient SR excitations and with sprites and other TLEs, and with ionospheric disturbances. The paper closes with some thoughts on future research directions based on the observations at NCK and Sopron and the results achieved since the IGY.     

The use of multivariate statistics to elucidate patterns of floodplain sedimentation at different spatial scales

Floodplains are depositional features of riverine landscapes that display complex sedimentation patterns that are amenable to multi‐scale approaches. We examined sedimentation in the Lower Balonne floodplain, Queensland, Australia, at three different spatial scales: the channel (10³ km), floodplain process zone (10 km) and geomorphic unit (10² m) scales, and compared scale‐related patterns evident from stratigraphy with those evident from quantitative multivariate analysis. Three stratigraphic sequences were found in the Lower Balonne floodplain: generally fining upward, episodic fining upward, and mud‐dominated. Stratigraphical analysis revealed the detailed character of sedimentary sequences embedded within the scale patterns derived from multivariate analysis. Multivariate statistical analyses of a range of textural and geochemical data revealed different patterns of floodplain sedimentation at each scale. At the channel scale, sediment texture and geochemistry were more heterogeneous in the Culgoa River than in Briarie Creek. At the floodplain process zone scale clear patterns of sediment texture and geochemistry were observed along the upper, mid and lower floodplain process zones of Briarie Creek, but not along the Culgoa River. At the geomorphic unit scale, clear patterns of sediment texture and geochemistry were observed among the bank, buried channel and flat floodplain units of the Culgoa River, but were not as clear in Briarie Creek. Recognition of rivers as hierarchically organized systems is an emerging paradigm in river science. Our study supports this paradigm by demonstrating that different sedimentation patterns occur at different scales to reveal a hierarchically organized floodplain environment. Copyright © 2006 John Wiley & Sons, Ltd.     

A high resolution lithospheric magnetic field model over China

CHAMP satellite data and ground-based magnetic observations are used and combined to map the lithospheric magnetic field over China by means of the revised spherical cap harmonic analysis(R-SHCA)modeling technique.The magnetic field is described to a spatial resolution of 150 km at the mean Earth’s radius,which represents a good compromise between the resolutions afforded by surface and satellite data.We compare the magnetic anomalies modeled at the regional scale with composite regions containing large-scale of tectonic structures.These regions,including the Tarim Basin and the Tibetan Plateau,are correlated with regional magnetic anomalies at satellite altitude but contain a significant number of small-scale and complex magnetic structures at the mean Earth’s radius.These magnetic anomalies are globally consistent with the known geological features in China but also offer a way to delineate the contours of the geological blocks and to discuss the connection between magnetic anomalies and the heat flow distribution in this region.