1∶50万地质图数据库的研建

全国1∶50万地质图数据库以国产软件MAPGIS作为基础平台，以各省（区）区域地质志附图和香港特别行政区1∶20万地质图为基础资料，采用现代地质学、地层学、岩石学等的新理论和新的表示方法，按岩石地层单位、花岗岩谱系单位，侵入岩按时代加岩性编制而成。该库由数字地质图库和地理底图库构成，可按任意空间范围、不同比例尺、不同投影方式和不同地质、地理内容等单项或多项任意检索；通过检索能自动形成具有图例、图外整饰的完整的地质图。     

基于ArcGIS Engine的地质灾害信息管理与应用

以地质灾害风险信息管理与应用为例,运用AE技术实现多源灾害信息统一管理、快速提取、专题图输出,揭示了GIS技术在此领域应用的可行性和广阔前景。     

城市消防地理信息系统的设计与实现

城市消防地理信息系统是消防指挥决策系统的一个重要组成部分,本文着重介绍了城市消防地理信息系统的结构、主要功能和特点。     

Use of Fuzzy Membership Input Layers to Combine Subjective Geological Knowledge and Empirical Data in a Neural Network Method for Mineral-Potential Mapping

Use of GIS layers, in which the cell values represent fuzzy membership variables, is an effective method of combining subjective geological knowledge with empirical data in a neural network approach to mineral-prospectivity mapping. In this study, multilayer perceptron (MLP), neural networks are used to combine up to 17 regional exploration variables to predict the potential for orogenic gold deposits in the form of prospectivity maps in the Archean Kalgoorlie Terrane of Western Australia. Two types of fuzzy membership layers are used. In the first type of layer, the statistical relationships between known gold deposits and variables in the GIS thematic layer are used to determine fuzzy membership values. For example, GIS layers depicting solid geology and rock-type combinations of categorical data at the nearest lithological boundary for each cell are converted to fuzzy membership layers representing favorable lithologies and favorable lithological boundaries, respectively. This type of fuzzy-membership input is a useful alternative to the 1-of-N coding used for categorical inputs, particularly if there are a large number of classes. Rheological contrast at lithological boundaries is modeled using a second type of fuzzy membership layer, in which the assignment of fuzzy membership value, although based on geological field data, is subjective. The methods used here could be applied to a large range of subjective data (e.g., favorability of tectonic environment, host stratigraphy, or reactivation along major faults) currently used in regional exploration programs, but which normally would not be included as inputs in an empirical neural network approach.     

全国自动地震速报系统评估

对全国自动地震速报系统进行了初步的评估. 通过2010年1月1日—2011年12月31日的自动定位结果与全国正式目录的对比, 分别得出了3套自动定位系统总体误差以及全国和全球的误差插值图, 并对结果进行了总结. 同时, 还针对3套自动定位系统的漏报和误报情况进行了分析和讨论. 总体来说, 现阶段自动地震速报系统整体上对于首都圈地区M≥3.0, 国内其它地区M≥4.0(部分台站稀疏的西部地区M≥5.0), 国外M≥7.0的地震基本可以达到全面覆盖的程度, 可以作为正式地震速报的参考, 对于建立“自动报—正式报”的两级地震速报制度能提供有力的技术支撑.     

数字地震数据的处理研究—真实地面运动的复原

讨论了在频域中真实地面运动的复原问题，借助于一个稳定的六阶带通滤波器可使地震仪反演系统趋于稳定，最后由关分方程递归求出真实地动位移，结果表明，对同一个地震，不同的仪器其原始响应不同，但由其复原的真实地面运动结果却有相当好的一致性。这证明了所采用的复原方法的可用性。     

An adaptive approach to selecting a flow‐partition exponent for a multiple‐flow‐direction algorithm

Most multiple‐flow‐direction algorithms (MFDs) use a flow‐partition coefficient (exponent) to determine the fractions draining to all downslope neighbours. The commonly used MFD often employs a fixed exponent over an entire watershed. The fixed coefficient strategy cannot effectively model the impact of local terrain conditions on the dispersion of local flow. This paper addresses this problem based on the idea that dispersion of local flow varies over space due to the spatial variation of local terrain conditions. Thus, the flow‐partition exponent of an MFD should also vary over space. We present an adaptive approach for determining the flow‐partition exponent based on local topographic attribute which controls local flow partitioning. In our approach, the influence of local terrain on flow partition is modelled by a flow‐partition function which is based on local maximum downslope gradient (we refer to this approach as MFD based on maximum downslope gradient, MFD‐md for short). With this new approach, a steep terrain which induces a convergent flow condition can be modelled using a large value for the flow‐partition exponent. Similarly, a gentle terrain can be modelled using a small value for the flow‐partition exponent. MFD‐md is quantitatively evaluated using four types of mathematical surfaces and their theoretical ‘true’ value of Specific Catchment Area (SCA). The Root Mean Square Error (RMSE) shows that the error of SCA computed by MFD‐md is lower than that of SCA computed by the widely used SFD and MFD algorithms. Application of the new approach using a real DEM of a watershed in Northeast China shows that the flow accumulation computed by MFD‐md is better adapted to terrain conditions based on visual judgement.     

断裂构造的遥感研究方法综述

断裂构造是一种基本的构造型式。断裂构造遥感研究是高新探测技术与地球科学的有机结合 ,是断裂构造常规研究方法的有益补充和向纵深拓展的必然趋势。该文从总体思路、具体内容、操作方法等各个不同角度系统地论述了断裂构造遥感研究的现状和发展趋势 ,并在断裂构造信息提取、光谱特征分析、空间结构分析 (包括分形分析 )等方面提出了一些观点。     

西准噶尔包古图Ⅴ号岩体围岩蚀变的特征及ETM+蚀变信息的提取

以新疆西准噶尔包古图Ⅴ号岩体为例,系统论述了包古图Ⅴ号含矿岩体的围岩蚀变分带和蚀变期次。结合ETM+数据的特征,选择多种遥感图像预处理方法组合,建立了基于典型蚀变矿物的特征光谱拟合技术的多光谱遥感蚀变信息提取模型,即遥感数据的归一化处理(Calibration )+掩膜(Mask)+混合像元分解(Endmember Unmixing)+波谱拟合(Spectral Feature Fitting)+ SAM+分类(分割)的CES模型。据此模型对岩体进行信息提取,并与化探资料叠加验证了该方法的可行性,取得了较满意的效果。     

Application of the HY-1 satellite to sea ice monitoring and forecasting

The HY-1A satellite is the first oceanic satellite of China. During the winter of 2002～2003, the data of the HY-1A were applied to the sea ice monitoring and forecasting for the Bohai Sea of China for the first time. The sea ice retrieval system of the HY-1A has been constructed. It receives 1B data from the satellite, outputs sea ice images and provides digital products of ice concentration, ice thickness and ice edge, which can be used as important information for sea ice monitoring and the initial fields of the numeric sea ice forecast and as one of the reference data for the sea ice forecasting verification. The sea ice retrieval system of the satellite is described, including its processes, methods and parameters. The retrieving results and their application to the sea ice monitoring and forecasting for the Bohai Sea are also discussed.