The Effect of Mantle Inelasticity On Tidal Gravity: A Comparison Between the Spherical and the Elliptical Earth Model   总被引：1，自引：0，他引：1  

V. Dehant  J. Zschau 《Geophysical Journal International》1989,97(3):549-555

  相似文献   

恒星导星器设计的新方案     

徐家岩  王正明 《时间频率学报》1992,15(2):121-125

  相似文献   

Measurement and prediction of water movement in a field soil: The matrix-macropore dichotomy     

K. R. J. Smettem  P. J. Ross 《水文研究》1992,6(1):1-10

The saturated and unsaturated flow properties of a field soil under two tillage treatments were obtained with ponded rings and disc permeameters of dissimilar radii. No difference was observed between tillage treatments but the flow properties displayed a distinct macropore-matrix dichotomy, with K changing by an order of magnitude as ψ₀ went from just - 30 mm to zero. Accurate prediction of time to incipient ponding was achieved using both numerical and analytical models calibrated with field hydraulic properties that were characteristic of the soil matrix. However, extension of the numerical model to the prediction of the wetting front development under non-ponded conditions was less accurate due to localized preferred wetting It is hypothesized that at this site, localized concentration of rainfall and hence, preferred wetting, May, occur by interception and stemflow associated with lines of standing stubble present in the original seeding slots.  相似文献   

A general solution for tide‐induced groundwater fluctuation in an estuarine‐coastal confined and unconfined aquifer system          下载免费PDF全文

Hsi‐Ting Fang  Yih‐Chi Tan  Mo‐Hsiung Chuang  Kai‐Yuan Ke  Po‐Chia Chen 《水文研究》2018,32(14):2239-2253

This paper presents an analytical solution to tide‐induced head fluctuations in a two‐dimensional estuarine‐coastal aquifer system that consists of an unconfined aquifer and a heterogeneous confined aquifer extending under a tidal river with a semipermeable layer between them. This study considers the joint effects of tidal‐river leakage, inland leakage, dimensionless transmissivity between the tidal‐river and inland confined aquifer, and transmissivity anisotropic ratios. The analytical solution for this model is obtained via the separation of variables method. Three existing solutions related to head fluctuation in one‐ or two‐dimensional leaky confined aquifers are considered as special cases in the present solution. This study shows that there is a threshold of tidal‐river confined aquifer length. When the tidal‐river length is greater than the threshold length, the inland head fluctuations remain sensitive to the leakage effect but become insensitive to the tidal‐river width and dimensionless transmissivity. Considering leakage and transmissivity anisotropy, this study also demonstrates that at a location farther from the river–inland boundary, head fluctuations increase with increasing leakage and transmissivity anisotropy; the maximum head fluctuation occurs when leakage and transmissivity anisotropy are both at their maximum values. The combined action of the 3 effects of loading, tidal‐river aquifer leakage, and inland aquifer leakage differs significantly according to various aquifer parameters. The analytical solution in this paper can be applied to demonstrate the behaviours of the head fluctuations of an estuarine‐coastal aquifer system, and the head fluctuations can be clearly described when the tidal and hydrogeological parameters are derived from field measurement data or hypothetical cases.  相似文献   

物理模型变率影响研究进展          下载免费PDF全文

窦希萍  王向明  赵晓冬 《水科学进展》2007,18(6):907-914

从理论分析、系列物理模型和数学模型三个方面对物理模型变率影响研究的进展情况作了概述。着重介绍了采用系列概化物理模型试验研究潮流和潮流、波浪共同作用下的模型变率影响问题,给出了进行潮流、波浪和泥沙物理模型的变率限制条件。  相似文献   

鄂尔多斯盆地西南缘镇泾油田6-2沉积相研究     

丁晓琪张哨楠  王少飞刘岩 《新疆地质》2007,25(1):105-110

延长组长6-2是鄂尔多斯盆地西南缘镇泾油田的一个重要勘探层位．通过岩心观察、测井资料、薄片研究、粒度分析，对镇泾油田长6-2沉积微相进行了深入研究．认为该区长6-2由一个完整的中期基准面旋回组成，水下分流河道主要发育在中期基准面缓慢上升初期和快速下降阶段，由于水下分流河道的强烈侵蚀作用，河口坝砂体不发育．中期基准面缓慢上升初期的河道具有深而窄的特点，砂体横向变化快，勘探难度大，而与之相对的是中期基准面快速下降阶段，水下分流河道具有厚而广的特点，为本区最为有利的勘探目的层．通过对不同可容空间下水下分流河道砂体厚度与河道宽度的研究，发现其具有很好的相关性，得出该区的砂体厚度与河道宽度的经验公式，为下一步勘探开发提供了强有力的理论依据。  相似文献   

Influence of Tide Models on the Use of Altimetry Data to Research Sea Level Anomaly     

XU Jun BAO Jingyang LIU Yanchun YU Caixia 《地球空间信息科学学报》2007,10(2):100-104

A tide model (named DN1.0), which contains 12 principal constituents over China seas and the Northwest Pacific is estimated by along-track harmonic analysis with TOPEX/Poseidon altimetry data taken from 1993 to 2002. CSR3.0, FES95.2 and DN1.0 are used respectively to detide the data for the time series of sea level anomaly (SLA) in the Yellow Sea, East China Sea, South China Sea and Northwest Pacific. The SLA curves and the power spectral density show that the major components that exist in SLA in China seas arise from the error of the tide models.  相似文献   

浙东象山港岸线及潮滩变迁遥感调查     

赵玉灵  杨金中 《国土资源遥感》2007,18(4):114-117

利用多期遥感数据，对浙江省东部象山港一带近30 a来的海岸线及潮滩变迁状况进行了调查与监测。结果表明，该区淤泥质海滩发育，海岸类型以淤泥质为主，岸线在1986～1996年间有较大变化，外迁宽度最大达1 700 m，1996年以后基本进入稳定状态。潮滩发育具有差异性。  相似文献   

地震活动性与日月引潮力相关性统计分析     

冯向东  魏东平 《国际地震动态》2007,93(5):9-15

基于ISC地震记录,利用天体动力学中二体问题的轨道方程和摄动理论,确定发震时刻太阳在地面的投影点位置,并进一步计算出太阳相对震中的地心天顶距,将地震按天顶距的大小进行统计,得到地震的太阳天顶距地震频度分布。同样的方法,可得地震的月球天顶距地震频度分布。统计发现:地震的太阳天顶距地震频度和月球天顶距地震频度分布表现出一致的规律性,且较大地震和小地震的活动规律不同,较大地震丛集发生在太阳(月球)天顶距0°和180°附近,与地面引潮力的绝对值分布有较好的一致性;而小地震多丛集在太阳(月球)天顶距60°和120°附近。在此基础上,我们对地震的日月天顶距同时进行统计,建立了日月天顶距地震概率密度分布,结果表明,日月投影点及其对蹠点周围,较大地震发生的概率较高。  相似文献   

梅雨锋结构特征及与锋上涡旋扰动关系的诊断分析   总被引：1，自引：0，他引：1  

陈丽芳  高坤 《大气科学》2007,31(5):863-875

利用1999年6月下旬持续性梅雨锋降水过程的模拟结果以及野外实验的加密资料，对这次梅雨锋过程进行诊断分析， 发现梅雨锋主；要表现为中层锋面，强度比边界层锋强，低涡沿中层锋面南缘移动。中层锋强的演变对两类低涡（西南涡和局地涡）发展的影响程度不同。对于东移明显的西南涡，梅雨锋强度的加强比低涡提早6小时以上。而对于长江中游的局地涡，锋面最强与低涡最强出现的时间却比较接近。梅雨锋中层锋面发展最强的位置与低涡发展最强的位置在东西方向上基本重合，基本在同一经度上。因此，低涡暴雨扰动加强发展区的北侧正是前期持续锋生所在，并且锋生的位置在东西方向上基本不随时间发生位移。当低涡移经该地时，低涡强度最强， 随后低涡东移并且强度减弱，锋面大值带也减弱并随低涡向东传播。  相似文献