西太平洋夏季三类声速环境下的会聚区特性比较

利用Argo剖面数据和水声学数值模型,分析了西太平洋夏季在热带海区(I型)、亚热带南部海区(II型)和亚热带北部海区(III型)三类典型声速环境下的会聚区特性。声场计算结果表明,声速环境的区域性差异及声源深度的变化对会聚区声场特性有明显影响。当声源深度为20m时,热带海区会聚区距离较远,第一会聚区约为65km,超出亚热带海区约5km;当声源深度为200m时,亚热带北部海区会聚区距离较远,第一会聚区约为60km,亚热带南部海区、热带海区依次递减约5km。I型和III型剖面在特定的声源深度条件下出现波导型声场,当声源位于表层时热带海区产生表面波导,当声源位于次表层时亚热带北部海区产生次表层波导,对于1kHz的声波,波导深度范围内的传播损失比波导深度以外高出10~20dB。     

真江蓠杭州湾海域栽培试验及生态因子对藻体生长的影响

在杭州湾上海金山海域进行了真江蓠(Gracilaria verrucosa)栽培试验并在实验室内研究了温度、盐度和光照强度对真江蓠生长的影响。结果表明,温度、盐度和光照强度对真江蓠的生长影响极显著(P0.01)。真江蓠生长适宜温度为20~30℃;适宜盐度为15~25;适宜光照强度在90μmol/(m2.s)左右。温度、盐度和光照强度对真江蓠生长存在显著的交互效应(P0.05),三者的最佳组合为温度25℃、盐度20和光照强度90μmol/(m2.s)。海区栽培实验表明真江蓠可在杭州湾海域正常生长,全年平均特定生长率(RSG)为9.42%/d。     

地磁场能量在地球内部的分布及其长期变化

用国际参考地磁场模型(IGRF)分析了地磁场能量在地球内部的分布及其长期变化.结果表明,从1900年到2005年,地核以外地磁场总能量由6.818×1018J减少到6.594×1018J,减小了3.3%,地表以外地磁场总能量由8.658×101J减小到.63×101J,减小了11.4%.分析地球内部不同圈层地磁场能量的变化表明,地壳(A层)、上地幔(B层)、转换带(C层)、下地幔D′层的地磁场总能量在减小,但是下地幔"层的地磁场总能量却在快速增加.磁能密度随时间的变化更清楚地显示出磁能增加和减小的分界面在r=3840km处.上述结果表明,地核和地表以外地磁场总能量在趋势性减小的同时,也在进行重新分配.进一步分析表明,下地幔D"层磁能快速增长,主要是由高阶磁多极子的增强引起的.在地磁场倒转前,偶极矩减小而多极性相对增强在能量分布上的表现就是磁能向下地幔底部(特别是D"层)集中.     

南坑河污染初步调查及河岸植物的富集能力

南坑河是新丰江的一条支流,直接汇入广东省最大的饮用水源地新丰江水库。野外调查中发现私自采矿和在河流沿岸洗矿等行为不断发生,大量洗矿废水未经处理直接注入南坑河,可能会造成污染。因此,采样初步分析了南坑河河水、河流底泥沉积物及附近优势植物的9种重金属元素含量。结果发现：与地表水II类标准相比,南坑河枯水期水体污染严重,其中连续2 a的铅、砷和汞超标,超标倍数分别为1.7~1.8、1.3~1.9和1.6~2.9倍,而底泥中铜、镉、铅、锌和砷均超标,超标倍数分别为4.8、9.0、3.9、4.3和10.9倍,镉和砷超标较为严重。另外,收集并鉴定了河岸或河漫滩中天然生长的15种植物,发现以蕨类植物和多年生禾草为主要类型。通过分析植物体内9种重金属元素含量,发现对砷吸附能力最强的当属蜈蚣草,其叶片中砷的含量（609.20 mg/kg）和茎干中砷的含量（814.77 mg/kg）均大于根部的砷含量（577.30 mg/kg）;蜈蚣草对铁、锰、铜和铅的吸附能力也远远大于其他河岸植物,可以作为良好地修复以砷为主的复合重金属污染土壤的富集植物。     

塔里木河下游河岸带地下水埋深对生态输水的响应过程

为了解塔里木河下游生态输水量与地下水埋深多年响应变化过程,得出地下水埋深对生态输水的响应变化规律,以塔里木河下游英苏断面为研究区,运用定性与定量分析方法,综合考虑不同输水差异（包括零输水年即2008年、输水极少年即2009年、输水较多年2011年等）,对2000-2015年英苏断面1 050 m范围内地下水埋深数据进行了分析。结果表明：研究断面内地下水埋深在各年份总体呈现比较平稳的递减趋势,年内个别月具有较大的增幅,另外由于冻土消融等因素影响,地下水埋深在2~3月有一定的增幅;离河较近区域的地下水埋深变化对生态输水的响应具有时间同步性,而离河道较远地区的地下水埋深在响应时间上存在滞后性,本研究断面1 050 m范围内地下水埋深响应时间维持在1 a内;经过多年生态输水过程,英苏监测断面距离河道约750 m范围内地下水平均埋深维持在2~6 m范围内,基本达到植物生长所需地下水埋深水平;另外,综合分析研究断面多年输水引起的地下水位响应过程,为获得生态输水过程所带来的最大生态效益,生态输水不仅要保持一定的输水量,还要保持输水年周期的连续性。     

Runoff quality prediction from small urban catchments using SWMM

The RUNOFF block of EPA's storm water management model (SWMM) was used to simulate the quantity and quality of urban storm water runoff from four relatively small sites (i.e. 5·97–23·56 ha) in South Florida, each with a specific predominant land use (i.e. low density residential, high density residential, highway and commercial). The objectives of the study were to test the applicability of this model in small subtropical urban catchments and provide modellers with a way to select appropriate input parameters to be used in planning studies. A total of 58 storm events, measured by the US Geological Survey (USGS), provided hyetographs, hydrographs and pollutant loadings for biological oxygen demand (BOD₅), total suspended solids (TSS), total Kjeldahl nitrogen (TKN) and lead (Pb), and were used for calibration of the model. Several other catchment characteristics, also measured or estimated by USGS, were used in model input preparation. Application of the model was done using the Green–Ampt equation for infiltration loss computation, a pollutant accumulation equation using a power build-up equation dependent on the number of dry days, and a power wash-off equation dependent on the predicted runoff rate. Calibrated quantity input parameters are presented and compared with suggested values in the literature. The impervious depression storage was generally found to be the most sensitive calibration parameter, followed by the Manning's roughness coefficients of conduit and overland flow, the Green–Ampt infiltration parameters and, finally, the pervious depression storage. Calibrated quality input parameters are presented in the form of regression equations, as a function of rainfall depth and the number of antecedent dry days. A total of 16 independent rainfall events were used for verification of the model, which showed a good comparison with observed data for both hydrographs and pollutant loadings. Average model predictions for the four constituent concentrations from the verification runs also showed good agreement with NURP published values in Florida and US sites. © 1998 John Wiley & Sons, Ltd.     

BOOK REVIEWS

Books reviewed in this article: Aerial Photography and Remote Sensing Aerial photography and image interpretation for Resource Management . DAVID P. PAINE . Analytical Models and Techniques Spatial Processes Models and Applications A. D. CLIFF AND J. K. ORD Quantitative and Statistical Approaches to Geography: A Practical Manual JOHN A. MATTHEWS . Cartography and Maps Map Data Processing . HERBERT FREEMAN AND GOFFREDO G. PIERONI , eds. Computer-assisted Cartography: Principles and Prospects, 1982 . MARK S. MONMONIER . Cultural Navajo Architecture: Forms, History, Distributions . STEPHEN C. JETT AND VIRGINIA E . SPENCER . Rational Landscapes and Humanistic Geography . EDWARD RELPH . Economic The Structure and Control of a State Economy . W. L. L'ESPERANCE . Economic Geography . JAMES O. WHEELER AND PETER O. MULLER . The Myth of the Family Farm: Agribusiness Dominance of U.S. Agriculture . INGOLF VOCELER . Libya: The Experience of Oil . J. A. ALLEN . Geography of Public Finance, Welfare Under Fiscal Federalism and local Government Finance . ROBERT BENNETT . Environmental Management, Resources, and Systems Mountains and Man . LARRY W. PRICE . Environmental Geology . DONALD R. COATES . An Introduction to Environmental Systems . G. H. DURY . The Environment: Chinese and American Views . Edited by LAURENCE J. C. MA AND ALLEN G. NOBLE . Land Use in America . RICHARD H. JACKSON . Medical Conceptual and Methodological Issues in Medical Geography . MELINDA S. MEADE (ed.). Philosophy and Geographic Thought Birds in Egg/Eggs in Bird . GUNNAR OLSSON . PhysicaI Climatology: Selected Applications . J. E. OLIVER . Geomorphological Techniques . ANDREW GOUDIE (ed.). Political Politics, Geography and Behaviour . RICHARD MUIR AND RONAN PADDISON . The State of the World Atlas . MICHAEL KIDRON AND RONALD SECAL . Population The Population of the South . DUDLEY L. POSTON , JR . AND ROBERT H. WELLER , eds. Regional Latin America: Economic Development and Regional Differentiation . ARTHUR MORRIS . Developing the Amazon . EMILIO F. MORAN . Western Europe: A Systematic Human Geography . BRIAN W. ILBERY . Settlement Systems in Sparsely Settled Regions: The United States and Australia . RICHARD E. LONSDALEAND JOHN H. HOLMES , eds. African Perspectives: The Economic Geography of Nine African States . HARM DE BUJ AND ESMOND MARTIN , eds. Rural Nonmetropolitan America in Transition . AMOS H. HAWLEY AND SARA MILLS MAZIE , eds. Social Crime and Environment . R. NORMAN DAVIDSON . The Ghetto: Readings with Interpretations . JOE T. DARDEN , ed. Urban Urban Problems and Planning in the Developed World . MICHAEL PACIONE (ed.) Problems and Planning in Third World Cities . Edited by MICHAEL PACIONE . The City in West Europe . D. BURTENSHAW , M. BATEMAN , AND C. J. ASHWORTH .     

深水工况下弧面胸墙沉箱堤的反射形态分析

为推广应用新型弧面胸墙沉箱堤,结合模型试验和数值模拟对比分析了深水工况下弧面胸墙沉箱堤和削角胸墙沉箱堤的反射形态。波面和波压的数值结果与试验数据吻合良好,验证了数值方法的有效性。反射系数表明,入射波浪在与弧面胸墙沉箱堤相互作用过程中的能量损耗最小,其反射强于削角胸墙沉箱堤。波面和流速包络图显示,两种堤型均在堤前形成了部分立波系统,腹点和节点以四分之一波长的距离增量交替出现,胸墙和直立部分产生的反射波存在相位差,导致初始腹点的位置向海侧偏移。弧面胸墙沉箱堤前叠合波的相位差影响最小,腹点包络高度最大,节点包络高度最小,反射效应最明显。两种堤型前中下层水流的周期平均速度均较小且对称,表明底床泥沙不会产生趋势性输移,但迎浪基床上方的环流系统可能引起局部冲刷。相对而言,弧面胸墙沉箱堤前的环流强度最弱,更有利于冲刷防护。     

深圳香港海域可能最高潮位和浪高计算分析

基于历史数据的分析,选择历史上强度最强的台风"荷贝"作为设计超强台风的强度,最不利路径的台风"雪莉"作为设计路径,作为深圳香港海域设计超强台风。采用海洋-陆架区-海岸三重嵌套网格建立的天文潮-风暴潮-台风浪耦合模型计算设计超强台风遭遇天文大潮的高潮位登陆时深圳香港海域的可能最高潮位和浪高。计算结果表明,大鹏湾北部和香港吐露港内,可能最高风暴潮位在3.00 m以上,浪高达到4.0～5.0 m;香港维多利亚港风暴潮位2.92 m,深圳香港水域东部南部在2.50 m以上,浪高3.0～5.0 m。可能最高风暴潮位比大鹏湾防潮警戒水位高1.62 m左右,比香港维多利亚港200年一遇的潮位高0.50 m。     

双侧向电阻率测井反演算法研究

双侧向测井仪因其激励源的复杂性给其测量数据的反演带来了极大的困难．本文利用变形玻恩（Born）迭代法对轴对称二维非均匀介质中双侧向测井仪的位场数据进行了严格反演．在每一次迭代过程中采用了高效数值模式匹配的正演计算方法,它可半解析地求出反演中所需计算的格林（Green）函数及其偏导数,同时利用所推导出的位场非线性积分方程中积分运算的半解析形式,大大提高了计算效率和反演质量．通过反演实例表明,反演结果与电导率原状剖面吻合较好,并且受噪声影响较小．