Defining shore platform boundaries using airborne laser scan data: a preliminary investigation

As an initial evaluation of the potential of digital elevation models (DEMs) and geographic information systems (GISs) for geomorphic characterization of rocky shorelines, airborne laser scan (ALS) data have been used to characterize shore platforms around Shag Point, southeastern New Zealand. The platforms have been characterized using field‐based techniques in previously published research, and therefore offer an ideal site for evaluation purposes. The main challenge involved the delineation of the shore platform area in terms of landward and seaward extents. The cliff top and landward edge of the shore platform was readily mapped, whereas the seaward edge of platforms was mapped with lesser precision due to difficulties associated with tidal inundation and the interference of wave action and surface water. In the central region of the study area (～0·1 km²) higher platform elevations and dense point cloud data enabled the generation of a high‐resolution (1 m) DEM. In analysing the DEM, ALS offered an advantage over the previous field survey in respect of the ability to assess continuous topography in plan‐view. The extent and form of two distinctive erosional surfaces is clearly apparent and was revealed through classifications based on slope and elevation. The spatial continuity of the upper surface implies that, in addition to the role of rock structure described in previous work, sea level and wave exposure may have been important factors in the generation and preservation of platform morphology at Shag Point. Copyright © 2007 John Wiley & Sons, Ltd.     

Subsidence history and forming mechanism of anomalous tectonic subsidence in the Bozhong depression, Bohaiwan basin

The Bozhong depression of the Bohaiwan basin belongs to a family of extensional basins in East China, but is quite different from other parts of the basin. The Cenozoic subsidence of the depression is controlled by a combination of lithospheric thinning and polycyclic strike-slip movements. Three episodic rifts have been identified, i.e. Paleocence-early Eocene, middle-late Eocene and Oligocene age. The depression underwent syn-rift and post-rift stages, but two episodic dextral movement events of the strike-slip faults modify the subsidence of the Bozhong depression since the Oligocene. The early dextral movement of the Tan-Lu fault associated with crustal extension resulted in accelerated subsidence during the time of deposition of the Dongying Formation with a maximum thickness of 4000 m. A late reactivation of dextral movement of the Tan-Lu fault began in late Miocene (about 12 Ma), which resulted in the intense subsidence of Minghuazhen Formation and Quaternary. In addition, dynamic mantle convection-driven topography also accelerated the post-rift anomalous subsidence since the Miocene (24.6 Ma). Our results indicate that the primary control on rapid subsidence both during the rift and post-rift stages in the Bozhong depression originates from a combination of multiple episodic crustal extension and polycyclic dextral movements of strike-slip faults, and dynamic topography.     

The deep-lake deposit in the Upper Triassic Yanchang Formation in Ordos Basin, China and its significance for oil-gas accumulation

The deep-lake facies of the Yanchang Formation represents a large outflowing lake basin in the Ordos area. Its deposition can be divided into four stages lake genetic and expanding stage, peak stage, inversion stage and dying stage. All the stages are obviously consistent with the evolution of depositional environment and the paleoclimate in the region. The study indicates that the lake basin has evolution fluctuations from highstand to lowstand for four times in its evolution history, and the deposition center of the lake has not obviously moved, staying along the Huachi-Yijun belt. The deep lake sedimentary system mainly consists of deep water deltas and turbidite fans during the entire evolution course of the lake basin in the Late Triassic. The former mainly developed on the slope of steep shore of the delta in the early period of the deep-water expansion and gradually experienced a big shift from deep-water deltas to shallow-water platform delta. And the latter appeared almost in all the above stages and had two types of turbidite fans, slope-moving turbidite fans and slump turbidite fans. The slope-moving turbidite fans have relatively complete facies belts overlapping one another vertically and consist of the slope channel of inter fans, the turbidite channel, inter turbidite channel and turbidite channel front of middle fans and outer fans (or lakebottom plain). However, the slide-moving turbidity fans are formed in the deep lake with their microfacies difficult to be distinguished, and only the center microfacies and edge microfacies can be determined. The two types of the turbidity fans are similarly distributing in the near-root-slope and far-root-slope regions. The deep-lake deposition governs the distribution of the hydrocarbon and reservoir, while the slope-moving turbidite fans are excellent reservoirs for oil-gas exploration due to their great thickness, widespread distribution and accumulation properties.     

对重力势二阶垂直偏导数的一种新的取样方法

从目前的研究来看，二阶垂直导数（X和Y两个方向）的求解方法较简单，它采用的五个因子的数字滤波的最小二乘法来优化数据。但是在较小区域面积时（对工程和环境应用中的重力数据），重力异常很容易放大和被区域重力场掩盖，我们认为产生的缘由是表示重力场的x和y方向上的二次多项式引起的。因此，为了逼近重力水平方向的偏导可以设计一个好的滤波器来拟合在xy平面的重力场值，再得出想要的重力垂直方向偏导，文中最后对提出的方法在前人经典模型上和野外实践进行了验证。     

正交实验法在测绘中的应用

以检测数字水准仪及标尺综合精度为例，介绍了正交实验法在测绘领域中的应用。     

GIS在"数字城市"中的应用与研究

根据在“数字厦门”项目策划、建设和应用推广的实际经验，对“数字城市”的理解作了阐述，介绍了“数字厦门”的主要建设内容和应用情况，探讨了与GIS有关的问题。     

正交实验法在测绘仪器检定中的应用

在测绘生产和科研项目中，为了改革旧工艺或对新仪器，新产品,经常需要做多因素实验，如何安排多因素实验，是一个很值得研究的问题，文中以数字水准仪及标尺综合精度的检定为例，介绍了正交实验法在测绘仪器检定中的应用。     

图幅磁偏角自动计算的原理和方法

详细论述了磁偏角自动计算的原理，并提出了一种利用地磁图自动计算图幅磁偏角的新方法，实验表明，用地磁图建立磁偏角数字模型和年变率数字模型进行图幅磁偏角的自动计算是可行的。     

武汉市轨道交通一号线一期工程基准复测分析

介绍武汉市轨道交通一号线一期工程基准复测的精度要求，阐述采用GPS，精密数字水准测量等技术进行轨道交通一号线一期工程基准复测的观测，数据处理及达到的精度，根据复测数据分析了基准点的变形原因和规律，得出了一些有益的结论和建议。     

现代科技与现代地名工作

主要论述了与地名相关的地球信息科学、数字地球、地理信息系统、数字地图与电子地图等现代科技的发展及利用现代科技进行地堍用字和读音规范、地名信息系统、地名标志、地名技术规范、地名科研与管理等现代化地名工作问题。