Book Reviews

Books reviewed: D. Graham Burnett, Masters of All They Surveyed: Exploration, Geography, and a British El Dorado Garrett A. Sullivan, Jr., The Drama of Landscape: Land Property and Social Relations on the Early Modern Stage Sergio Díaz‐Briquets and Jorge Pérez‐López, Conquering Nature: The Environmental Legacy of Socialism in Cuba Karl F. Nordstrom, Beaches and Dunes of Developed Coasts Robin W. Doughty, The Eucalyptus: A Natural and Commercial History of the Gum Tree James K. Mitchell, ed., Crucibles of Hazard Gerald T. Koeppel, Water for Gotham: A History Arnold R. Alanen and Robert Z. Melnick, eds., Preserving Cultural Landscapes in America Kavita Pandit and Suzanne Davies Withers, eds., Migration and Restructuring in the United States Steven R. Nivin, Regional Innovation Potential: The Case of the U.S. Machine Tool Industry Douglas Meyer, Making the Heartland Quilt: A Geographical History of Settlement and Migration in Early Nineteenth‐Century Illinois David R. Meyer, Hong Kong as a Global Metropolis Mark Cleary and Goh Kim Chuan, Environment and Development in the Straits of Malacca David Zurick and P. P. Karan, Himalaya: Life on the Edge of the World Christer Jönsson, Sven Tägil, and Gunnar Törnqvist , Organizing European Space Tor Bernhardsen, Geographic Information Systems: An Introduction, 2nd ed.     

地壳介质的各向异性弹性本构关系讨论

论述了地壳介质中存在的几类各向异性弹性本构关系，推导了应变能变换公式、EDA薄层各向异性弹性常数及非对称面上EDA构成的单斜对称弹性常数的计算公式，讨论了几种各向异性对称系统的特征方程，并给出了弹性波的角散表达式，最后选取合理的参数对波的角散现象进行了数值模拟。     

岩石声频散的实验研究及声波速度的外推

对岩石声频散进行了实验研究，用不同频率的声学探头使用超声波脉冲穿透法对砂岩和泥岩样品进行了测量，并分析了两者的频散现象.结果表明：在51kHz-1MHz频率范围内，在干燥状态下岩芯有频散现象；在饱水状态下，砂岩的频散现象更明显，岩芯中流体的存在是影响纵波频散的一个重要原因.利用频散方程计算不同频率时的速度值，并与实验结果进行了比较，说明频散方程可以较好的描述砂岩与泥岩的频散关系.     

多重分形与地质统计学方法 用于勘查地球化学异常空间结构和奇异性分析

勘查地球化学和地球物理场的局部空间结构变化性应包括空间自相关性以及奇异性 .前者可通过地质统计学中常用的变异函数来实现 ;后者可用多重分形模型进行刻划 .具有自相似性或统计自相似性的多重分形分布 (multifractaldistributions)的奇异性 (α)可以反映地球化学元素在岩石等介质中的局部富集和贫化规律 .而多重分形插值和估计方法可以同时度量以上两种局部结构性质 (空间自相关性以及奇异性 ) ,因而 ,它不仅能够进行空间数据插值 ,同时还能保持和增强数据的局部结构信息 ,这对于地球化学和地球物理异常分析和识别是有益的 .应用该方法处理加拿大NovaScotia省西南部湖泊沉积物地球化学砷等元素数据表明 ,地球化学数据的局部奇异性在该区能够反映局部金和钨 -锡 -铀矿化蚀变带或岩相变化以及构造交汇等局部成矿有利部位 .     

2000—2001年商丘严重春旱成因分析

2000—2001年商丘市乃至北方大部分地区连续出现历史上最严重的春旱。分析结果表明：巴尔喀什湖到贝加尔湖地区以及我国东北一带高度场较常年同期异常偏高，暖性高压脊在这一带的频繁出现和发展，主导环流系统为高压脊且长时间维持，是造成2000—2001年春旱的主要原因；偏低的赤道东太平洋海温和太阳活动异常是造成2000—2001年春旱的间接原因。     

On evolution of bed material waves in alluvial rivers

Field and laboratory measurements have shown distinct characteristics of bed sediment waves under differing conditions, whilst their theoretical interpretation has emerged to be equivocal. This note aims to clarify the interpretation of evolution of bed material waves. The complete set of governing equations for the flow–sediment–morphology system is deduced to demonstrate its universally hyperbolic nature, irrespective of the sediment transport functions implemented to close the equations. The hyperbolic nature can admit not only attenuating bed material waves, but also shock‐like waves that are not unusual in the real world. It is suggested that the theory of dispersion/diffusion is not universally appropriate for evolution of bed material waves. Copyright © 2003 John Wiley & Sons, Ltd.     

Effect of exchangeable Mg on saturated hydraulic conductivity, disaggregation and clay dispersion of disturbed soils

Different opinions exist regarding the specific effect of Mg on soil physical and chemical properties. We hypothesized that Mg²⁺, compared with Ca²⁺, reduces saturated hydraulic conductivity (K_s) via promoting clay swelling, disaggregation, and clay dispersion. Two soils (mixed, mesic Typic Hapludalfs) in packed soil columns were leached with either Ca- or Mg-containing solutions at the successive concentrations of 250, 10, 2, 0.5, and 0 mM. Critical flocculation concentration (CFC) in either Ca or Mg systems was determined with flocculation series tests. Aggregate stability and mean weight diameter (MWD) were assessed by wet-sieving. The CFCs were higher in Mg than in Ca for both soils, indicating that Mg is more dispersive than Ca. The MWDs measured using 1–2 mm aggregates of both soils were significantly larger for Ca-soils than for Mg-soils (P=0.05). The K_sr (normalized with initial K_s) started to decline at higher concentrations for Mg than for Ca, and the reduction was much greater in Mg than in Ca above 0.5 mM. The K_sr and percent transmittance (inversely related to turbidity) of leachate at a given eluted pore volume following ‘steady state’ were higher in Ca than in Mg for both soils (P=0.1), indicating lower permeability and more clay dispersion with the Mg treatment. Swelling and disaggregation, which reduced large pores, appeared to be the dominant process causing the rapid initial decline of K_sr. Clay dispersion and subsequent pore plugging became progressively important when electrolyte concentration was reduced to below CFCs.     

利用伽玛能谱资料探索深部放射性元素分布的方法

本文根据放射性元素与大地热流之间的内在关系，从理论上说明利用伽玛能谱资料探索深部放射性元素分布的可能性，并采用数据综合处理的方法推导出计算公式。通过对云南省２８０１铀矿化地区的实际应用，证明该方法具有一定的实用价值，并成功地应用于实际资料处理之中。