A new method of estimating the ratio between in situ rock stresses and tectonics based on empirical and probabilistic analyses   总被引：1，自引：0，他引：1  

L.I. Gonzlez de Vallejo  T. Hijazo 《Engineering Geology》2008,101(3-4):185-194

This paper describes a new procedure for assessing the ratio between in situ stresses in rock masses by means of K (K = σ_H / σ_v, being σ_H and σ_v principal stress) and tectonics for purposes of engineering geology and rock mechanics. The method combines the use of the logic decision tree and the empirical relationship between the Tectonic Stress Index, TSI, and a series of K in situ values obtained from an extensive database. The decision tree considers geological and geophysical factors affecting stress magnitudes both on the regional and local scale. The TSI index is defined by geological and geomechanical parameters. The method proposed provides an assessment of the magnitude of horizontal stresses of tectonic origin. Results for several regions of Europe are presented and the possible applications of the procedure are discussed.  相似文献   

On the Assessment of Failure in Slope Stability Analysis by the Finite Element Method   总被引：3，自引：0，他引：3  

H. Zheng  D. F. Liu  C. G. Li 《Rock Mechanics and Rock Engineering》2008,41(4):629-639

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Implementation of reconstructed geomorphologic units in landslide susceptibility mapping: the Melen Gorge (NW Turkey)   总被引：6，自引：2，他引：4  

T. Gorum  B. Gonencgil  C. Gokceoglu  H. A. Nefeslioglu 《Natural Hazards》2008,46(3):323-351

In the international literature, although considerable amount of publications on the landslide susceptibility mapping exist, geomorphology as a conditioning factor is still used in limited number of studies. Considering this factor, the purpose of this article paper is to implement the geomorphologic parameters derived by reconstructed topography in landslide susceptibility mapping. According to the method employed in this study, terrain is generalized by the contours passed through the convex slopes of the valleys that were formed by fluvial erosion. Therefore, slope conditions before landsliding can be obtained. The reconstructed morphometric and geomorphologic units are taken into account as a conditioning parameter when assessing landslide susceptibility. Two different data, one of which is obtained from the reconstructed DEM, have been employed to produce two landslide susceptibility maps. The binary logistic regression is used to develop landslide susceptibility maps for the Melen Gorge in the Northwestern part of Turkey. Due to the high correct classification percentages and spatial effectiveness of the maps, the landslide susceptibility map comprised the reconstructed morphometric parameters exhibits a better performance than the other. Five different datasets are selected randomly to apply proper sampling strategy for training. As a consequence of the analyses, the most proper outcomes are obtained from the dataset of the reconstructed topographical parameters and geomorphologic units, and lithological variables that are implemented together. Correct classification percentage and root mean square error (RMSE) values of the validation dataset are calculated as 86.28% and 0.35, respectively. Prediction capacity of the different datasets reveal that the landslide susceptibility map obtained from the reconstructed parameters has a higher prediction capacity than the other. Moreover, the landslide susceptibility map obtained from the reconstructed parameters produces logical results.  相似文献   

光诱鱿鱼浮拖网渔具渔法试验报告     

郑国富??  郑雅友??  戴天元??  洪明苇??  黄桂芳 《海洋科学》2001,25(4):5-8

1989－1999年开展光诱鱿鱼浮拖网渔具渔法研究的生产试验结果为：1998年生产试验86个夜（航次），总产量33．225t，其中鱿鱼产量为12．470t，占总产量的37．5％，总产值139000元，比同村光诱敷网的平均产量（31．62t）高5．1％左右。1999年生产试验80夜（航次），总产量54．66t，其中鱿鱼产量31．92t，占总产量的58．4％，总产值187000元。试验网产量比同村光诱敷网的平均产量（45．64t)增产19．76％，产值增加22．65％，鱿鱼产量占总渔获量的比例提高近10个百分点，投入产出比为1：1．684。取得了较好的试验结果，达到了预期试验目的。此外，文中还讨论了水上灯数量，网具规格和柔性网板等对生产效果和捕捞对象的影响及适应性情况，并建议开展光场强度及其分布的海上实测和光场强度对鱿鱼，趋光性鱼类的行为习性以及生长影响等试验研究，制定出光诱鱿鱼浮报网和敷网作业诱鱼灯数量和分布标准，以合理利用鱿鱼和中上层鱼类资源，实现可持续发展。  相似文献   

莱州湾温带风暴潮预报研究   总被引：1，自引：1，他引：1  

张胜平  徐振山  王军  丁吉龙  侯庆华 《海洋预报》2002,19(1):64-72

本文依据莱州湾羊角沟、夏营两站建国以来的风暴增水资料，对莱州湾建国后发生的风暴潮进行了统计分析，并探讨了温带风暴潮产生的物理机制，此外还对莱州湾温带风暴增水以及诱发增水的天气形势进行了分析分类。在此基础上建立了莱州湾温带风暴潮统计预报方法，并在作业预报中对模型进行了检验，取得较为理想的效果。  相似文献   

Resources calculation of cobalt-rich crusts with the grid subdivision and integral method     

WU Ziyin  CHU Fengyou  MA Weilin  LI Shoujun  SHANG Jihong 《海洋学报(英文版)》2007,26(5):43-53

On the basis of three geological models and several orebody boundaries,a method of grid subdivision and integral has been proposed to calculate and evaluate the resources of cobalt-rich crusts on the seamounts in the central Pacific Ocean.The formulas of this method are deduced and the interface of program module is designed.The method is carried out in the software "Auto mapping system of submarine topography and geomorphology MBChart".This method and program will possibly become a potential tool to calculate the resources of seamounts and determine the target diggings for China's next Five-year Plan.  相似文献   

Reliability of a model based on a short fishery statistics survey: application to the Northeast Atlantic monkfish fishery     

Rocha  Francisco; Gracia  Joaquin; Gonzalez  Angel F; Jardon  Carlos M; Guerra  Angel 《ICES Journal of Marine Science》2004,61(1):25-34

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A Zonal Pathway for NADW in the South Atlantic     

Nelson?G.?HoggEmail author  Andreas?M.?Thurnherr 《Journal of Oceanography》2005,61(3):493-507

Several large deployments of neutrally buoyant floats took place within the Antarctic Intermediate (AAIW), North Atlantic Deep Water (NADW), and the Antarctic Bottom Water (AABW) of the South Atlantic in the 1990s and a number of hydrographic sections were occupied as well. Here we use the spatially and temporally averaged velocities measured by these floats, combined with the hydrographic section data and various estimates of regional current transports from moored current meter arrays, to determine the circulation of the three major subthermocline water masses in a zonal strip across the South Atlantic between the latitudes of 19°S and 30°S. We concentrate on this region because the historical literature suggests that it is where the Deep Western Boundary Current containing NADW bifurcates. In support of this notion, we find that a net of about 5 Sv. of the 15–20 Sv that crosses 19°S does continue zonally eastward at least as far as the Mid-Atlantic Ridge. Once across the ridge it takes a circuit to the north along the ridge flanks before returning to the south in the eastern half of the Angola Basin. The data suggest that the NADW then continues on into the Indian Ocean. This scheme is discussed in the context of distributions of dissolved oxygen, silicate and salinity. In spite of the many float-years of data that were collected in the region a surprising result is that their impact on the computed solutions is quite modest. Although the focus is on the NADW we also discuss the circulation for the AAIW and AABW layers.  相似文献   

Hammerstein型非线性积分方程解的存在性     

白锦东  刘秀元 《中国海洋大学学报(自然科学版)》2002,32(1):152-158

该文采用化为积分方程组的方法 ,利用锥上不动点指数计算 ,在不要求非线性项 f (x,u)非负的情况下 ,证明 Hammerstein型非线性积分方程 φ(x) =∫Gκ(x,y) f (y,φ(y) ) dy非平凡解和多解存在性的一些新的结果。此结果可用来证明非线性常微分方程两点边值问题解的存在性。  相似文献   

Application of a two-dimensional depth-averaged hydrodynamic tidal model     

S. Sankaranarayanan  D. French McCay 《Ocean Engineering》2003,30(14):1807-1832

A two-dimensional hydrodynamic model application to the San Francisco Bay was performed using the Boundary-Fitted HYDROdynamic model (BFHYDRO). The model forcing functions consist of tidal elevations along the open boundary and fresh water flows from the Delta Outflow. The model-predicted surface elevations compare well with the observed surface elevations at five stations in San Francisco Bay. Mean error in the model predicted surface elevations and currents are less than 7 and 9%, respectively. Correlation coefficients for surface elevations and currents are higher than 0.94 and 0.95, respectively. The amplitudes and phases of the principal tidal constituents at 24 tidal stations in San Francisco Bay, obtained from a harmonic analysis of a 90-day simulation compare well with the observed data. The predicted amplitude and phase of the M₂ tidal constituent at these stations are respectively within 8 cm and 8° of the observed data. Maximum errors in the K₁ harmonic amplitudes and phases are less than 3 cm and 7° respectively. The asymmetric diurnal and semi-diurnal tidal ranges and spring and neap tidal cycles of the surface elevations and currents are well reproduced in the model at all stations.  相似文献