场地地震动局部地形效应研究进展

本文对地震动地形效应的影响因素及其规律进行了阐述和分析.主要对局部地形几何形状,入射波的入射角度、频率,震源相对位置及震源深度等因素对地形效应影响的国内外研究现状进行了综述.同时,介绍了地震数值模拟在地震动地形效应研究中的应用,并对进一步研究提出了一些建议.     

TRMM卫星降水数据在川渝地区的适用性分析

在地形复杂的川渝地区,利用72个气象站点的实测降水数据对TRMM(Tropical Rainfall MeasurementMission)卫星降水数据的精度分别在年、季和月尺度上进行验证,并进一步分析了高程和坡度对月尺度验证结果的影响,同时借助主成分分析法,对比了高程与坡度对TRMM 3B43降水数据的影响程度.结果表明:TRMM3B43估算的年降水量在川渝地区平均偏高5.38％,其中西部高原区估算结果比中东部地区相对精确.TRMM3B43与气象站点的季尺度降水数据拟合优度较高,但各季拟合优度之间存在差异,其中春季降水的拟合优度高于其余季节.而TRMM 3B43的月数据与站点实测降水数据拟合优度R2=0.7615,相关系数R=0.87,表明两者之间相关性显著,数据精度较高;就单个站点而言,大部分站点相关系数较高,误差较小,但叙永站相关系数相对较低,小金、雅安、雷波、盐源以及攀枝花站点数据误差相对较大.高程对数据精度的影响较坡度大,且呈现三次非线性回归的变化特征,随着高程的升高,R呈现增大的变化趋势,|Bias(％)|则呈现出增大—减小—增大的变化趋势;坡度对降水数据精度的影响相对较小且变化规律也较复杂,整体上随坡度变化,TRMM 3B43数据精度受到明显的影响.     

Mark on the globe: a quest for scientific bases of geographic information and its international influence

David M. Mark published his first journal article in 1970. Since then, he has written or coauthored more than 220 publications over a period of 40 years as of 28 May 2012. Based on data from Web of Science (WoS) and Google Scholar, Mark’s publications have been cited over 7410 times by researchers in more than 80 countries or regions as of 28 May 2012, when this paper was first prepared. The geographic extent of Mark’s scholarly influence is truly global. An examination of his 20 most cited articles reveals that his work in diverse areas as digital elevation models, geomorphology, geographic cognition, and ontology of the geospatial domain enjoyed a lasting impact worldwide.     

A new rainwater harvesting and recycling system for transforming sloping land into terraced farmland

Transforming sloping land into terraced land is an effective approach to cope with the problems including farmland shortage and severe soil erosion.This paper introduces a new system based on rainwater harvesting and recycling technology,which may effectively improve farmland productivity rainwater use efficiency and reduce water and fertilizer inputs.The new system consists of three subsystems：1） A plough layer with the dual function of crop cultivation and rainwater harvesting; 2） A tank below the plough layer for storing water; 3） An irrigation-drainage subsystem.The plough layer and the storage tank,both treated for reducing seepage,are connected through the irrigation and drainage system.Results showed that,compared with the traditional paddy fields,rice evapotranspiration（ and crop coefficient） in the test field remained at a similar level,while the irrigation amount was reduced by 44.3% under the condition of basin irrigation,and the drainage amount decreased by 86.6%,and the non-point source pollution was reduced to 67.7%~87.9%,and the rainwater utilization efficiency increased by 30% and reached 95.4%,and crop yield of middle-season rice reached 9,975 kg/hm2,which was only 0.4% lower than that in the traditional paddy field in the terms of dry matter.The new technology sheds light on new possibilities for transformation of hilly sloping land.     

台湾岛地形对台风“海棠”(0505)移动路径影响的数值试验研究

利用非静力模式MM5模拟台风“海棠”（0505）穿过台湾岛再次登陆的移动路径，分析了“海棠”登陆台湾岛前后结构特征变化。结果表明：台风自身的非对称结构与台风异常移动路径密切相关。另外，就台湾岛地形对台风“海棠”登陆台湾前打转和在台湾海峡出现“V”型移动异常路径影响进行数值试验表明：台湾岛地形不但可以直接影响台风移动路径，而且通过影响台风非对称结构来改变台风移动路径，因此，登陆台湾前逆时针打转异常路径是在弱引导气流中台风自身非对称结构和台湾岛地形共同作用的结果；台湾岛地形有使台风东北-西南向非对称增大趋势，而在台风进入台湾海峡前后对东南。西北向非对称有明显不同影响。     

琼州海峡大风数值模拟及地形敏感性试验

使用WRF3.1模式对2008年12月4日、12月21日、2009年3月13日的三次冷空气造成的琼州海峡大风过程进行数值模拟和地形敏感性试验.模拟结果表明:水平格距4 km的模拟地面风场与实况接近,中尺度模式在大风的起风时间、持续时间、风速大小等方面有较强的预报能力,并能反映冷空气偏东路径与偏西路径过程中琼州海峡大风的...     

SOFTWARE REVIEWS

Electromap World Atlas , Version 1.1. Interactive Population Statistical System , Version 1.0. Jerry W. Wicks and Jose Luiz Pereira de Almeida MATHCAD , Version 2.5. Memory Mate. Micro DEM +, Version 5.21. Peter Guth NCSS – Number Cruncher Statistical System , Version 5.02. Dr. Jerry L. Hintze     

Mapping waterlogging of soils using digital terrain models

Maps of the potential waterlogging of soils were generated using hypotheses about the effect of topography on the soil water regime inspired by Beven and Kirkby's concept of saturation overland flow. The procedure was validated by comparing the simulated maps with maps derived from a 1: 25 000 soil survey for two contrasting catchments. The value and limitations of the method are discussed in the light of this comparison. The approach proposed here is relevant to modelling the distribution of intensely waterlogged soils, provided the relationship between bedrock and the limit values is established. This approach can be used for several purposes: (1) to distinguish positional waterlogging from other types of waterlogging; (2) to control the quality and consistency of waterlogging maps; and (3) to create soil water regime maps for non-surveyed catchments. Conversely, soil water regime maps can be compared with contributing areas simulated by hydrological distributed models for validation purposes.     

基于IDL的地形三维可视化实现

作为一种第四代的编程语言,IDL具有对海量数据进行获取、分析、可视化以及对多种图像进行处理和交互式操作的功能。在分析IDL的基础上,应用组件编程技术实现了对遥感图像和DEM数据进行地形三维合成及动态模拟的可视化系统设计,经对环境的三维再现和模拟,对生态环境的演变研究可以起到指导作用,而且它具有较好的系统维护和重复使用功能、易于扩展以及面向对象的特点。用该系统建立了吉林西部虚拟自然环境,对三维地形进行空间分析,及吉林西部生态环境数据库的空间和属性数据的查询。