地缘经济视角下中日资源贸易关系测度与分析

大国是全球政经版图的主导力量,其关系性质对区域、全球发展和经济合作过程具有决定性影响,结构性变动、资源和市场高度对外依赖性引发了大国博弈新态势。在资源争夺加剧的地缘经济时代,如何平衡国家间的资源竞合关系是当今政治地理学的时代命题。以中日两国2000—2017年资源贸易为例,以库仑引力模型构建地缘经济合作强度指标,探讨中日资源贸易的地缘经济规律。研究表明：①中日两国资源贸易的地缘经济合作强度多为负值,总体上竞争大于合作,2008年后两国地缘经济关系进入矛盾与对抗新阶段;②按照竞合关系可将中日资源贸易货物分为强竞争型、波动竞合型以及合作潜力型,其中化石能源、稀有金属和农产品是影响中日两国地缘经济竞合关系的关键资源;③资本主义世界经济体系的演化是中日资源贸易关系变动的重要外因,对发展权的争夺构成两国在世界市场资源博弈的内在根源,稀有金属为中国捭阖两国关系提供了地缘政治杠杆。     

中国城市发展中的地质环境问题

本文在研究我国城市地质环境背景和主要地质环境问题的基础上,运用多层次动态系统方法,提出了协调城市人类工程活动和地质环境的对策。     

Recent changes in the sediment regime of the Pearl River (South China): Causes and implications for the Pearl River Delta

Riverine sediments have played an important role in the morphological evolution of river channels and river deltas. However, the sediment regime in the many world's rivers has been altered in the context of global changes. In this study, temporal changes in the sediment regime of the Pearl River were examined at different time scales, that is, annual, seasonal, and monthly time scales, using the Mann–Kendall test. The results revealed that precipitation variability was responsible for monthly and seasonal distribution patterns of the sediment regime and the long‐term changes in the water discharge; however, dam operation has smoothed the seasonal distribution of water discharge and resulted in decreasing trends in the annual, wet‐season, and dry‐season sediment load series since the 1950s. Due to the different regulation magnitudes of dam operation, differences were observed in sediment regime changes among the three tributaries. In addition, human activities have altered the hysteresis of seasonal rating curves and affected hysteresis differences between increasing and decreasing water discharge stages. Sediment supply is an important factor controlling river channel dynamics, affecting channel morphology. From the 1950s to the 1980s, siltation was dominant in river channels across the West River and North River deltas in response to the sediment increases; however, scouring occurred in the East River deltas due to sediment reduction. Significant erosion occurred in river channels in the 1990s, which was mostly due to downcutting of the river bed caused by sand excavations and partly because of the reduced sediment load from upstream. Although sand excavations have been banned and controlled by authority agencies since 2000, the erosion of cross sections was still observed in the 2000s because of reduced sediment caused by dam construction. Our study examines the different effects of human activities on the sediment regime and downstream channel morphology, which is of substantial scientific importance for river management.     

Patterns in groundwater chemistry resulting from groundwater flow

 Groundwater flow influences hydrochemical patterns because flow reduces mixing by diffusion, carries the chemical imprints of biological and anthropogenic changes in the recharge area, and leaches the aquifer system. Global patterns are mainly dictated by differences in the flux of meteoric water passing through the subsoil. Within individual hydrosomes (water bodies with a specific origin), the following prograde evolution lines (facies sequence) normally develop in the direction of groundwater flow: from strong to no fluctuations in water quality, from polluted to unpolluted, from acidic to basic, from oxic to anoxic–methanogenic, from no to significant base exchange, and from fresh to brackish. This is demonstrated for fresh coastal-dune groundwater in the Netherlands. In this hydrosome, the leaching of calcium carbonate as much as 15 m and of adsorbed marine cations (Na⁺, K⁺, and Mg²⁺) as much as 2500 m in the flow direction is shown to correspond with about 5000 yr of flushing since the beach barrier with dunes developed. Recharge focus areas in the dunes are evidenced by groundwater displaying a lower prograde quality evolution than the surrounding dune groundwater. Artificially recharged Rhine River water in the dunes provides distinct hydrochemical patterns, which display groundwater flow, mixing, and groundwater ages. Received, May 1998 · Revised, August 1998 · Accepted, October 1998     

A nonparametric characterization of vertical ground motion effects

Design guidelines have traditionally oversimplified the vertical ground motion effects by defining a constant vertical‐to‐horizontal response spectral ratio (V/H). With the recognition that such practice is not always conservative, recent studies have proposed improvements to the representation of vertical seismic effects in design codes, based on empirical ground motion relations. Conventional empirical modeling requires selecting the functional form of the predictive model. Because of the complicated nature of ground motions, identification of the underlying function is a challenge. A related drawback to this approach is its high susceptibility to overfitting, especially with today's highly complex models. To address these issues, this paper proposes a nonparametric approach to characterize the vertical seismic effects. Using support vector machines, the V/H ratio is determined without an assumed functional form. The accuracy of the model is measured by adopting an epsilon‐insensitive residual function with a regularization term added to prevent overfitting. An example application using ground motion records from strike‐slip and normal faulting earthquakes is presented, and the results are compared with a current empirical model, for different magnitude, distance, and local soil conditions. The median V/H estimates from the two models are shown to be in good general agreement. The standard deviation estimates from the proposed model are consistently larger than the estimates from the empirical model. The results from this study show that the proposed method is a viable alternative and offers the opportunity to characterize vertical seismic effects without an assumed functional form. Copyright © 2011 John Wiley & Sons, Ltd.     

Etna and the Perception of Volcanic Risk

Sicily's uneven geological structure is positioned within a system of tectonic plates, and its very active volcano has always made it prone to disasters. Many Sicilian cities have in fact been destroyed by natural events many times over the centuries. This can certainly be understood negatively as the destruction of entire towns, the emission of volcanic ash, and the mutation of landscapes by a terrifying force have instilled fearful memories in local populations. But from another point of view one must consider the positive elements of Etna. Its beautiful landscapes were a major attraction on the Grand Tour, and its inhabitants have long associated the volcano with the concept of rebirth and fertility. This paper analyzes two age groups of residents in the town of Nicolosi and is a small part of an ongoing research project that is much more complex, involving representative samples of the entire population of several towns around Etna.     

人类活动对青藏高原冻土环境的影响

采用物探技术、植物样方调查对青藏公路沿线工程活动对冻土环境因素之间的影响进行了分析研究, 结果表明: 由于工程活动对原冻土区地貌、植被及表土层结构等的干扰破坏, 致使工程区及其影响区冻土上限下降速度加快, 同时得出了冻结层上水埋深(1～3 m)与冻土层厚度变化的关系以及冻结层上水水位随冻土上限下降而变化的规律. 指出工程活动对植被的影响不仅与工程本身有关, 也与工程区冻土厚度、地下水、土壤等因素有密切关系.     

百年SSCI看国际人文地理学的发展特点与规律——基于73种人文地理类期刊的文献计量分析

从文献总量、文献类型、成长趋势、关键词、作者、国家与机构等方面,对1900-2012年SSCI收录的73种人文地理期刊的144719条文献记录,进行了较为全面的文献计量分析,包括:构建作者评价指标体系以分析作者对人文地理研究的学术贡献,利用网络图分析各阶段作者、国家与机构之间合作的网络关系等。研究表明:1百年来,人文地理发文量总体呈快速上升趋势,但占SSCI发文总量的比重却呈下降趋势;2英美一直引领全球人文地理研究及其发展;3人文地理学有明显研究热点主题,包括地方性、迁移、性别、旅游、规划等,研究注重地理与政治的结合,以及对GIS和RS为代表的地理信息技术的采借;研究热点区域集中在英、美两国,尤以其特大城市为重点,中国的部分城市近十年来也受到较多关注;4人文地理学作者分布有明显阶段性特征,并形成了以Johnston R J、Thrift N、Sayer A、Jackson P、Harvey D等为中心的学术高产核心作者群。本研究对揭示人文地理学发展的特征和趋势有较好的参考借鉴。     

水文学研究进展与展望

水文学是研究地球上水的起源、存在、分布、循环运动等变化规律,并运用这些规律为人类服务的知识体系。水文学研究经历了由经验到理论、由简单过程到复杂系统、由定性描述到定量模拟的发展历程,其学科体系演进与科学技术进步及社会发展需求紧密联系,并由此衍生出诸如生态水文学、气象水文学、冰冻圈水文学、遥感水文学、同位素水文学、城市水文学、社会水文学等多种交叉研究领域与分支学科。当今水文学研究在水文多尺度观测、陆面—水文—社会耦合模拟及多源观测—模型同化技术等领域取得显著进展,水文学研究的广度和深度不断拓展。未来水文学研究将面向陆地水文循环的变化规律及其效应,重点关注水文循环变化特征和机理、水文循环变化趋势预估及水文循环变化的自然和社会影响等前沿课题;从原有就水论水研究思路转向在自然地理综合分析框架下以水循环为纽带开展的多尺度、多过程集成研究。