航空物探在水工环勘查中的应用     

王卫平  王守坦 《物探与化探》2007,31(Z1):1-3

航空物探在水工环勘查中具有覆盖面积大、速度快、周期短等特点,到目前为止,已经完成了多个测区的生产测量和成果解释工作,并取得了明显的勘查效果。根据以往国内航空物探在水工环方面的勘查效果,并分析国际上近年来利用航空物探进行水工环勘查的实例,提出了航空物探在水工环勘查领域的优势和应用前景。  相似文献   

下一代地球物理观测技术     

王喜珍  王宝善  马洁美  张东宁  滕云田 《国际地震动态》2007,(9):44-58

地球物理观测技术所要解决的问题是观测什么、用什么来观测、怎样观测。下一代地球物理观测技术的发展是以解决上述问题为基础。论文详细论述了观测设备、观测系统以及地球外行星体结构探测等发展动态,并对下一代地球物理观测技术的发展方向进行了分析。  相似文献   

Dauphiné twinning and texture memory in polycrystalline quartz. Part 1: Experimental deformation of novaculite     

Hans-Rudolf Wenk  Erik Rybacki  Georg Dresen  Ivan Lonardelli  Nathan Barton  Hermann Franz  Gabriela Gonzalez 《Physics and Chemistry of Minerals》2006,33(10):667-676

Mechanical Dauphiné twinning in quartz has been of long-standing interest, both in single crystals and polycrystalline aggregates. This study investigates texture development in fine-grained quartz rock novaculite with no initial texture using compression experiments conducted in the Paterson gas apparatus to explore the influence of stress and temperature. Texture patterns are measured with time-of-flight neutron diffraction and hard synchrotron X-rays, analyzing diffraction data with the Rietveld method. Similar texture patterns are observed as described previously but the new results establish a profound influence of temperature and document that twinning initiates at stresses less than 50 MPa. Possibilities of using Dauphiné twinning as a paleopiezometer in quartz-bearing rocks are discussed.  相似文献   

Response of sand ripples to change in oscillatory flow   总被引：3，自引：1，他引：3  

J. S. DOUCETTE  T. O'DONOGHUE 《Sedimentology》2006,53(3):581-596

Ripples take time to evolve to a new equilibrium state in response to a change in wave-generated oscillatory flow. The paper presents results from flow tunnel experiments designed to examine oscillatory flow transient ripple processes under controlled, full-scale laboratory conditions. The experiments include study of the growth of ripples from flat bed and the evolution of existing ripples to new equilibrium ripples in response to a step change in the flow. In general, ripples evolve through a combination of two main processes: (i) from a flat bed or from a bed consisting of ripples that are smaller than the equilibrium ripples through a combination of 'slide' and 'merge'; (ii) from a bed consisting of ripples that are larger than the equilibrium ripples through a combination of 'split' and 'merge'. The experimental results show that equilibrium ripple geometry is independent of initial bed morphology while the time to reach equilibrium is largely independent of the initial bed and the equilibrium ripple size. The time to reach equilibrium depends strongly on the mobility number, and a new empirical equation relating mobility number and the number of flow cycles to equilibrium is proposed. This equation is combined with a simple exponential function for ripple height growth or decay to produce a new empirical model for ripple height evolution, which gives a reasonably good overall agreement with the measurements. The model is based on experiments involving one sediment size only and further work is needed to develop the model for other sand sizes.  相似文献   

Using neural networks to predict thermal conductivity from geophysical well logs   总被引：2，自引：1，他引：2  

Bruno Goutorbe  Francis Lucazeau  Alain Bonneville 《Geophysical Journal International》2006,166(1):115-125

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Experimental tests of simple models for the dynamics of diffuse oceanic plate boundaries   总被引：1，自引：0，他引：1  

A. Mark Jellinek  Richard G. Gordon  Stephen Zatman 《Geophysical Journal International》2006,164(3):624-632

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分布式水文-土壤-植被模式的改进及气候水文Off-line模拟试验   总被引：12，自引：3，他引：12  

王守荣  黄荣辉  丁一汇  L.R.Leung  M.S.Wigmost  L.W.Vail 《气象学报》2002,60(3):290-300

文中对引进的高分辨率 (94 2 .5m× 94 2 .5m)分布式水文 土壤 植被模式 (DHSVM) ,针对海、滦河流域的特点进行了改进 ,主要包括 :(1)改变蒸散发模拟方法 ,用改进的Penman Monteith模式模拟海滦河流域的蒸发 ,较好地模拟出 1a内的两个峰值 ,最大值出现在 4～ 6月 ,次大值出现在 7～ 8月 ;(2 )改变水文模式结构 ,用多站点气候观测资料内插到模式网格点 ,充分实现了分布式水文模拟 ;(3)发展新的水文、植被、土壤参数化方案 ,对 33个参数分区计算和确定 ,并重点对土壤孔隙度 φ、土壤蓄水能力θfc、叶面指数LAI、随机阻抗γs 等 11个参数进行调试和修订 ,提高了水文模拟精度。用改进的DHSVM模式分别对滦河、桑干河流域蒸散发、地下水位、土壤湿度、土壤水下渗、产流、汇流与径流等水文过程进行Off line模拟试验 ,模拟结果与实测值一致性较好 ,滦河流域 1979～ 1991年、桑干河流域 1979～ 1987年水文模拟效率系数分别为 0 .89和 0 .82 ,均高于国内其他相关研究  相似文献   

由大尺度观测提取中尺度信息的可能性研究     

邱崇践  张述文 《气象学报》2002,60(5):538-543

利用浅水方程模式和变分四维同化方法对由大尺度观测提取中尺度信息的可能性进行了模拟试验研究。试验的初始场是在平直气流上叠加一个半径为 5倍格距的圆形涡旋。分别设定观测点的间距是 5 ,7和 9倍格距 ,观测的时间间隔分别是 1,2和 3h ,同化时间为 6h或 12h ,考察同化产生的初始场。试验结果是 :观测点的间距是 5倍格距时 ,由观测给出的分析场不能反映涡旋的基本特征 ,而在同化产生的初始场中 ,涡旋的基本结构清楚 ,但强度有所削弱。增加观测次数或者延长同化时间 ,可以改善同化的结果。对于移动较快的系统 ,同化的结果较好。当观测点的间距是 9倍格距时 ,同化的结果与分析场相比已无明显改进。  相似文献   

Review on Deep Geoplhysical Exploration and Research in China     

WangChunyong 《中国地震研究》2002,16(3):283-292

The status of deep geophysical exploration and research in China is summarized in this paper.New achievements in the study of the velocity structure,seismotectonics and geodynamics of the crust and upper mantle are also briefly descibed.  相似文献   

Scale effects of Hortonian overland flow and rainfall‐runoff dynamics: laboratory validation of a process‐based model     

T. J. Stomph  N. de Ridder  T. S. Steenhuis  N. C. Van de Giesen 《地球表面变化过程与地形》2002,27(8):847-855

Hortonian runoff was measured in the laboratory from uniform slopes of lengths of 1·5, 3·0, and 6·0 m for steady, high‐intensity rainstorms with durations of 1·0 to 7·5 min. A clear reduction in runoff per unit slope length was found as slope lengths were increased. This effect becomes more pronounced with decreasing storm duration. The runoff data were used to validate a simple process‐based model that combines the Philip‐two‐term infiltration equation with the kinematic wave overland flow principle. The predicted and experimental results agreed well. Laboratory findings were extrapolated with the aid of the model to slopes and rainfall durations similar to those found under West African conditions. The calculated reduction of runoff per unit length is similar to reported observations. Thus, this process‐based model can largely explain the phenomenon of runoff reduction with increasing slope length. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献