浙江泰顺县地质灾害易发区划分方法探讨

开展1∶1万地质灾害易发区图编制工作,可为地质灾害防治规划、土地利用总体规划、地质灾害危险性评估、建设工程选址等提供可靠的资料,对做好地质灾害防治工作具有重要意义。本文以泰顺县为例,采用地质灾害综合危险性指数法划分地质灾害易发区,总结分析地质灾害易发程度分区评价的经验,为大比例尺易发区图编制作一些有益的探讨。     

Quantitative Limits to Qualitative Engagements: GIS,Its Critics,and the Philosophical Divide∗

Heated exchanges between critical theorists and GIScientists over geographic information systems (GIS) in 1990s geography gave rise to calls for increased communication between critics and practitioners of the technology and most recently for “hybrid” qualitative–quantitative GIS practices. Although GIS scholars have successfully addressed mid-1990s critiques of the technology by developing a series of critical GIS practices that involve nuanced and reflexive deployments of GIS and assessments of its visual products, theoretical critiques of GIS remain fixated on the epistemological deficiencies of the technology. Despite references to loosening metaphysical tensions across the discipline, this difference in assessments reveals the discourses of critical-theoretic geography and GIScience to remain separated by a trenchant philosophical divide, across which ontological and epistemological commitments are inviolable. The inability to fully reconcile a critical–theoretic epistemology with the explicitly ontological metaphysics of GIS further complicates qualitative engagements with the technology by addressing a series of inconsistencies into GIS praxis arising from the quantitative limits to representation encountered in the formal universe of computing. The persistence of metaphysical tensions in critical engagements with the technology questions the degree to which qualitative methods can be seamlessly hybridized with the quantitative architectures of GIS.     

Change and continuity of income divide in the American Southeast: A metropolitan scale analyses, 2000–2014

Changing racial/ethnic diversity along with economic growth have also drawn renewed public attention to growing income inequality and lack of economic well-being in the American society. This paper investigates one element of contemporary inequality – the income divide between the richest and the poorest population groups in the metropolises of the U.S. Southeast. This paper examines income divide across southern U.S. metropolises in 2000 and 2014, their change during 2000–2014, their variation across major races/ethnicities, and their relationships with important metropolitan characteristics such as diversity, intermixing, socio-economic status and built-environment attributes. Cartographic, ranking/matrix, and correlations analyses suggest that the largest, most diverse, most segregated, and those with a greater presence of better educated are the most income divided metropolises, whereas the small-to-mid-sized metropolises, with lesser educated population are less divided. The income divide has increased during 2000–2014 in a majority of these metropolises, and for all races/ethnicities, even though Whites and Asians are relatively better-off compared to overall population whereas Blacks and Hispanics lag behind.     

A thermodynamic model for silicate melt in CaO–MgO–Al2O3–SiO2 to 50 kbar and 1800 °C

A fully thermodynamic model for mafic melt in CaO–MgO–Al₂O₃–SiO₂ (CMAS) has been calibrated, for calculation of melting equilibria in the pressure range 0–50 kbar. It is intended as a preliminary step towards a large‐system melt model, suitable for exploring melting, melt loss and crystallization processes in a wide range of natural rock compositions. Calibration was performed with attention to the model's behaviour in its compositional subsystems, as a rigorous test of model structure and parameterization. The model is consistent with the latest Holland & Powell thermodynamic data set, and can therefore be used to calculate phase relations in conjunction with the many solid‐phase activity–composition models written for the data set. Model calculations successfully reproduce experimental melting reactions in CMAS spinel lherzolite and garnet lherzolite assemblages, as well as sapphirine‐ and kyanite‐bearing assemblages, at moderate to high pressure. Thermodynamically sensitive features, such as thermal divides are also recovered. However, some changes to the model structure will be required before the model can describe the full range of mafic and ultramafic melt compositions known from experiment at low pressures.     

世界信息化发展空间格局及对中国的启示

20世纪90年代以来,信息技术的蓬勃发展对全球的社会经济活动及其空间过程产生了深刻的影响。其中,尤其值得地理学家关注的是,各个国家和地区的信息化发展水平(尤其是信息技术基础设施)的空间不均衡分布(即所谓的"数字鸿沟"),这将影响社会经济活动的区位选择。信息时代,良好的区位意味着可接近、快速沟通与高收益的网络,即高信息化发展水平。在这种背景下,本文通过模糊层次分析法建立信息化评价指标体系,测算全球154个国家和地区的信息化发展水平,并计算洲际层面和国家层面的变差系数CV,系统研究世界信息化发展进程、空间格局及存在的数字鸿沟。另外,还分析并揭示了我国信息化发展与发达国家之间的差距,以期对中国信息化发展提出政策和建议。     

Geochemistry of waters and brines from the Salinas Grandes basin,Córdoba,Argentina. II. Gypsum dissolution-calcite precipitation,and brine evolution

Rivers and streams originating in the surrounding mountainous area are the major sources of salt in the Salinas Grandes basin (Córdoba, Argentina). These rivers infiltrate when they reach the sandflat or in the fringes of the mudflat, feeding springs which often form shallow lakes. Presently, the lakes are distant from the playa edge, thus allowing inflow waters to dissolve ancient (Pleistocene?) evaporite beds. In the sandflat environment, two dominant types of water have been recognized (SO ₄ ^2? -Cl^?-HCO ₃ ^? -Na⁺, and Cl^?-SO ₄ ^2? -HCO ₃ ^2? -Na⁺), both considered as original members of the brine in the saline complex. Two main sources of solutes were distinguished, one related to the waters supplied by the southern sector and another to waters of the eastern sector. As a result of the chemical evolution in the playa environment, all brines belong to the neutral type (Cl^?-SO ₄ ^2? -Na⁺). Following Hardie and Eugster's (1970) model, waters from the southern sector should evolve towards an alkaline brine (Cl^?-SO ₄ ^2? -HCO ₃ ^? -Na⁺), whereas those from to the eastern sector should evolve towards a neutral one (Cl^?-SO ₄ ^2? -Na⁺). A computer simulation was carried out to model the chemical evolution of source waters. The results obtained by this methodology showed the same dichotomy (alkaline vs. neutral) established by Hardie and Eugster's (1970) model. The deficit in alkalinity could not be explained by any of the mechanisms published until now. Gypsum dissolution is the most likely mechanism which accounts for the chemical evolution of the waters investigated. When such a process is included in the computations, the Ca²⁺ supplied by gypsum beds generates an increase in the ion activity product (aCa⁺²·aCO ₃ ^2? ) and produces a significant change in the 2Ca⁺²/(2CO ₃ ^2? +HCO ₃ ^? ) ratio, switching from values less than 1 to values greater than 1. This process determines the precipitation of calcite, and leads to a decrease in alkalinity, which in turn would explain the existence of a neutral brine in the saline complex. An intermediate salinity brine was detected in the mudflat, which, according to the model (Hardie and Eugster, 1970), should evolve towards a SO ₄ ^2? -free neutral brine (Cl^?-Na⁺-Ca²⁺). The absence of this type of brine may be explained through mixing processes.     

三峡水利枢纽库区巫山县城新址地质环境质量预断评价

在系统分析新址地质环境条件、预断评价的目标、环境要素的构成基础上,选用敏感因子综合评价模型对新址地质环境质量进行了预断评价,分析了评价成果,提出了新城建设-地质环境系统调控措施,可作为合理制定新城规划、进行建设和环境保护的依据。     

松辽分水岭的水文地质特征及其对生态环境的影响

晚更新世以来形成的松辽分水岭是松辽平原新构造运动中最重要的地质事件之一,也是松辽平原西部脆弱生态环境恶化的重要地质因素.通过对松嫩平原分水岭的形成演化、地质及水文地质特征的研究,论述松辽分水岭的形成对松辽平原西部生态环境的影响,认为松辽分水岭是通榆、长岭、乾安、双辽一带水资源缺乏及生态环境恶化的重要地质因素,治理和保护生态环境应考虑到这一新构造运动的影响.     

进入21世纪以来中国互联网发展的时空差异及其影响因素分析

进入21世纪以来,中国的互联网事业得到了飞速发展,但目前的普及率还远远低于大多数发达国家或地区。在空间上,中国东、中、西地区的互联网普及率差异显著,省际发展存在极大的地域集中性,同时,城乡之间也存在着明显的数字鸿沟。通过分别对2001年和2008年31个省市(区)的从经济、文化、社会等方面选取的11项指标进行因子分析,得出影响区域互联网普及率的3个主因子:区域现代化综合水平因子、区位因子和信息基础设施因子,并对其进行多元回归,发现各个主因子的影响系数发生了较大变化。最后,动态地分析了各个主因子是如何影响互联网发展与变化的,并为中国的互联网发展提供一些政策建议。