空间关系及其应用

GIS中的空间关系主要描述空间对象之间的各种关系,为GIS的分析提供基本的理论和方法支持。空间关系主要包括距离关系、方向关系、拓扑关系及空间关系相似性等。从空间关系的内涵来讲,空间关系模型应该能够反映目标尺度、人类认知、目标层次、现象的不确定以及随时间变化等特性对空间关系的影响;从数学角度来看,空间关系模型必须是可形式化和可推理的,以方便操作和实现;空间关系从人们认知的角度对空间现象和目标间的关系进行建模,因而在空间数据查询、检索、空间数据挖掘、空间场景相似性评价以及图像理解等应用领域得到了广泛应用。现有GIS模型主要针对二维平面的简单对象、确定的现象进行建模,因而大多数空间关系模型只描述和推理二维平面对象和确定现象的空间关系,三维空间关系、不确定空间关系、复杂目标间的多层次空间关系推理、遥感图像空间关系的抽取、描述与推理将是未来空间关系研究和发展的重要方向。     

Landslide and debris-flow hazard analysis and prediction using GIS in Minamata–Hougawachi area, Japan

On July 20, 2003, following a short duration of heavy rainfall, a debris-flow disaster occurred in the Minamata–Hougawachi area, Kumamoto Prefecture, Japan. This disaster was triggered by a landslide. In order to assess the landslide and debris-flow hazard potential of this mountainous region, the study of historic landslides is critical. The objective of the study is to couple 3D slope-stability analysis models and 2D numerical simulation of debris flow within a geographical information systems in order to identity the potential landslide-hazard area. Based on field observations, the failure mechanism of the past landslide is analyzed and the mechanical parameters for 3D slope-stability analysis are calculated from the historic landslide. Then, to locate potential new landslides, the studied area is divided into slope units. Based on 3D slope-stability analysis models and on Monte Carlo simulation, the spots of potential landslides are identified. Finally, we propose a depth-averaged 2D numerical model, in which the debris and water mixture is assumed to be a uniform continuous, incompressible, unsteady Newtonian fluid. The method accurately models the historic debris flow. According to the 2D numerical simulation, the results of the debris-flow model, including the potentially inundated areas, are analyzed, and potentially affected houses, river and road are mapped.     

上海开展地理市情监测工作的思考

根据国家开展地理国情监测工作的要求,结合上海规划和土地管理中的实际情况,阐述了对地理市情监测主要内容和技术方法的认识和思考,分析了上海地区开展此项工作的基础以及存在的主要难点。     

澳大利亚塔斯马尼亚地学数据属性描述与GIS空间数据库的集成管理

地学数据种类极为繁多,它既包括定量信息,也包括定性信息。数字地质信息结构的研制工作所面临的困难是以何种方式保存现有的模拟数据的重要内容,使得在ＧＩＳ中能够进行各种有效的查询和处理。澳大利亚斯马尼亚地调局为了对地质图信息和地球化学进行编码而研制了数据结构。在地质和地球化学数据结构中对于一系列相关表格中的属性进行编码,而这些表格利用“一对多”和“多对多”的关系有效而准确地阐明了原始数据之间的相互关系。     

GIS技术在四川省九龙县地质灾害危险性评价中的应用

文章结合九龙县地质灾害调查与区划项目,在对全县地质灾害特征和影响因素调查基础上,探讨了GIS技术在九龙县地质灾害危险性评价中的应用,描述了GIS图形处理和空间分析功能支持下的地质灾害危险性评价思路,并介绍了评价因子选取、栅格单元划分、结果评价等问题。分析结果表明,将GIS技术应用于九龙县地质灾害危险性评价中可以提高评价效率和准确性,评价效果较好。     

地理信息系统(GIS)在我国地学中的应用

地理信息系统是近年来发展迅猛的一项高新技术。笔者回顾了地理信息系统(GIS)在国内外的发展现状,分析了应用地理信息系统进行地学研究的主要优势,介绍了地理信息系统在我国地图编制、自然地理资源管理、资源评价及环境整治等领域中的研究与应用现状及部分科研成果,说明了地理信息系统在研究地学问题中,方法是先进的,理论是可行的,结语中展望了GIS前景。     

地理信息系统及其在水文水资源中的应用

简要介绍了地理信息系统(GIS)和近十年来GIS在水文水资源领域中的应用。讨论了在具体应用中,如何选择GIS软件包。作为个例,介绍了爱尔兰国立大学都柏林学院水资源研究中心应用地理信息系统——ARC/INFO开发研究的流域水管理决策支持系统。     

基于GIS的磐石市地下水环境质量分析

基于ArcGIS建立了磐石市29个监测点的水质信息数据库,采用灰色聚类法进行地下水环境质量评价。利用GIS的空间分析功能,分析地下水中常规组分的空间分布特征,掌握了地下水质量状况。磐石市大部分地区地下水质量良好,达到、级标准。地下水中化学组分的含量从郊区向市区逐渐增加,市区地下水质量为、级标准。地下水已遭受污染,地下水开采降落漏斗区地下水位的持续下降是市区地下水遭受污染的主要诱发因素。     

The hydrochemical facies and anomalous fluoride content in the Serra Geral aquifer system,southern Brazil: a GIS approach with tectonic and principal component analysis

Groundwater with high fluoride content and water mixture patterns were studied in Serra Geral aquifer system (SGAS) using three aspects, principal component analysis (PCA), tectonic scenery and hydrochemical interpretation from 309 groundwater chemical data information from deep wells. A four-component model is suggested and explains 81% of total variance in the PCA. Six hydrochemical facies were identified. These facies suggest two different fluoride sources. Tectonic approach shows the relationship between defined hydrochemical facies and regional fracture control. The applied methodology reveals a minimum level to understand hydrochemical mixtures. The fluoride enrichment mechanisms into the groundwater are comprised in advance to guide the future uses of SGAS to the public supply.     

Groundwater study using remote sensing and geographic information systems (GIS) in the central highlands of Eritrea

Remote sensing, evaluation of digital elevation models (DEM), geographic information systems (GIS) and fieldwork techniques were combined to study the groundwater conditions in Eritrea. Remote sensing data were interpreted to produce lithological and lineament maps. DEM was used for lineament and geomorphologic mapping. Field studies permitted the study of structures and correlated them with lineament interpretations. Hydrogeological setting of springs and wells were investigated in the field, from well logs and pumping test data. All thematic layers were integrated and analysed in a GIS. Results show that groundwater occurrence is controlled by lithology, structures and landforms. Highest yields occur in basaltic rocks and are due to primary and secondary porosities. High yielding wells and springs are often related to large lineaments, lineament intersections and corresponding structural features. In metamorphic and igneous intrusive rocks with rugged landforms, groundwater occurs mainly in drainage channels with valley fill deposits. Zones of very good groundwater potential are characteristic for basaltic layers overlying lateritized crystalline rocks, flat topography with dense lineaments and structurally controlled drainage channels with valley fill deposits. The overall results demonstrate that the use of remote sensing and GIS provide potentially powerful tools to study groundwater resources and design a suitable exploration plan.The online version of the original article can be found at     

Groundwater study using remote sensing and geographic information systems (GIS) in the central highlands of Eritrea

Remote sensing, evaluation of digital elevation models (DEM), geographic information systems (GIS) and fieldwork techniques were combined to study the groundwater conditions in Eritrea. Remote sensing data were interpreted to produce lithological and lineament maps. DEM was used for lineament and geomorphologic mapping. Field studies permitted the study of structures and correlated them with lineament interpretations. Hydrogeological setting of springs and wells were investigated in the field, from well logs and pumping test data. All thematic layers were integrated and analysed in a GIS. Results show that groundwater occurrence is controlled by lithology, structures and landforms. Highest yields occur in basaltic rocks and are due to primary and secondary porosities. High yielding wells and springs are often related to large lineaments, lineament intersections and corresponding structural features. In metamorphic and igneous intrusive rocks with rugged landforms, groundwater occurs mainly in drainage channels with valley fill deposits. Zones of very good groundwater potential are characteristic for basaltic layers overlying lateritized crystalline rocks, flat topography with dense lineaments and structurally controlled drainage channels with valley fill deposits. The overall results demonstrate that the use of remote sensing and GIS provide potentially powerful tools to study groundwater resources and design a suitable exploration plan.An erratum to this article can be found at     

GIS 系统在海南石碌铁矿成矿预测中的应用

GIS(地理信息系统)成矿预测技术是依据多元地学变量空间信息进行成矿预测及综合研究的新技术.GIS成矿预测工作,多元地学数据库建立是基础,软件设计是关键.根据石碌铁矿野外考察结果及对石碌铁矿成矿规律的认识,确定将双透岩、含矿层位、古地貌、构造、重力异常5个地学变量作为成矿预测变量.将石碌含矿层按50×50×50m规格划分为15224个待预测块,用成矿预测变量对待预测块进行综合打分,统计已知含矿预测块同成矿预测变量综合打分的关系,确定每个待预测块的成矿概率.通过预测,在石碌铁矿外围,一级成矿预测块2618块,有望找到一亿多吨富铁矿.GIS成矿预测技术为危机矿山外围及深部找矿提供了新的思路及方法.     

Development of a sharp interface model that simulates coastal aquifer flow with the coupled use of GIS

A simulation program, which works seamlessly with GIS and simulates flows in coastal aquifers, is presented in the present paper. The model is based on the Galerkin finite element discretization scheme and it simulates both steady and transient freshwater and saltwater flow, assuming that the two fluids are separated by a sharp interface. The model has been verified in simple cases where analytical solutions exist. The simulation program works as a tool of the GIS program, which is the main database that stores and manages all the necessary data. The combined use of the simulation and the GIS program forms an integrated management tool offering a simpler way of simulating and studying saline intrusion in coastal aquifers. Application of the model to the Yermasogia aquifer illustrates the coupled use of modeling and GIS techniques for the examination of regional coastal aquifer systems.

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Resumen Se ha desarrollado un modelo casi tridimensional de elementos finitos para simular el flujo de agua dulce y salada, tanto en régimen estacionario como en transitorio, en sistemas acuíferos costeros, bajo la hipótesis de separación por medio de una interfaz abrupta. Las ecuaciones del modelo han sido discretizadas mediante un esquema de Galerkin de discretización en elementos finitos. El modelo ha sido verificado en casos sencillos para los que existe solución analítica. Todos los datos necesarios se introducen y gestionan con un Sistema de Información Geográfica [SIG] por ordenador. El programa de simulación forma parte del programa de SIG, constituyendo una herramienta integrada de gestión para estudiar la intrusión salina en acuíferos costeros. La aplicación del modelo al acuífero de Yermasogia ilustra el uso acoplado de las técnicas de modelación y de SIG con el fin de examinar sistemas acuíferos costeros a escala regional.

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Résumé Pour étudier un système aquifère côtier, nous avons développé un modèle aux éléments finis en quasi 3-D qui simule les écoulements deau douce et deau salée en régime aussi bien permanent que transitoire. Les équations qui les régissent sont discrétisées par un schéma de discrétisation de Garlekin aux éléments finis. Le modèle a été vérifié dans des cas simples où il existe des solutions analytiques. Toutes les données nécessaires sont introduites et gérées grâce à un logiciel de gestion de SIG. Le programme de simulation est utilisé comme un outil du logiciel de SIG, constituant ainsi un outil de gestion intégrée dont le but est de simuler et détudier lintrusion saline dans les aquifères côtiers. Lapplication du modèle à laquifère de Yermasogia illustre lutilisation couplée de la modélisation et des techniques de SIG pour létude des systèmes aquifères côtiers régionaux.

     

Landslide susceptibility mapping using GIS and digital photogrammetric techniques: a case study from Ardesen (NE-Turkey)

Ardesen is a settlement area which has been significantly damaged by frequent landslides which are caused by severe rainfalls and result in many casualties. In this study a landslide susceptibility map of Ardesen was prepared using the Analytical Hierarchy Process (AHP) with the help of Geographical Information Systems (GIS) and Digital Photogrametry Techniques (DPT). A landslide inventory, lithology–weathering, slope, aspect, land cover, shear strength, distance to the river, stream density and distance to the road thematics data layers were used to create the map. These layer maps are produced using field, laboratory and office studies, and by the use of GIS and DPT. The landslide inventory map is also required to determine the relationship between these maps and landslides using DPT. In the study field in the Hemsindere Formation there are units that have different weathering classes, and this significantly affects the shear strength of the soil. In this study, shear strength values are calculated in great detail with field and laboratory studies and an additional layer is evaluated with the help of the stability studies used to produce the landslide susceptibility map. Finally, an overlay analysis is carried out by evaluating the layers obtained according to their weight, and the landslide susceptibility map is produced. The study area was classified into five classes of relative landslide susceptibility, namely, very low, low, moderate, high, and very high. Based on this analysis, the area and percentage distribution of landslide susceptibility degrees were calculated and it was found that 28% of the region is under the threat of landslides. Furthermore, the landslide susceptibility map and the landslide inventory map were compared to determine whether the models produced are compatible with the real situation resulting in compatibility rate of 84%. The total numbers of dwellings in the study area were determined one by one using aerial photos and it was found that 30% of the houses, with a total occupancy of approximately 2,300 people, have a high or very high risk of being affected by landslides.     

Remote sensing and GIS based determination of groundwater dependent ecosystems in the Western Cape, South Africa

Finding the location of groundwater dependent ecosystems (GDEs) is important in determining the extent of restrictions that need to be placed upon the abstraction of groundwater. Remote sensing was combined with geographical information system (GIS) modelling to produce a GDE probability rating map for the Sandveld region, South Africa. Landsat TM imagery identified the areas indicating the probable presence of GDEs and GIS assisted in their delineation. Three GIS models were generated: a GIS model predicting landscape wetness potential (LWP model) based on terrain morphological features; the LWP model was modified to highlight groundwater generated landscape wetness potential (the resulting GglWP model); and a groundwater elevation model was interpolated, combining groundwater level measurements in boreholes in the region with digital elevation model data. Biomass indicators generated from Landsat were classified and combined with the GIS models, followed by field verification of riverine and wetland GDEs. The LWP model provided the most accurate results of the three models tested for GDEs in this region.

Combining rough sets and GIS techniques to assess aquifer vulnerability characteristics in the semi-arid South Texas

The coastal semi-arid region of South Texas is undergoing significant growth causing an enormous burden on its limited water resources. Understanding regional-scale vulnerability of this resource is important for sustainable water resources management and land use development. In this study, DRASTIC methodology is integrated with an information-analytic technique called rough sets to understand groundwater vulnerability characteristics in 18 different counties of South Texas. The rough set theory provides three useful metrics: the strength factor which depicts how vulnerability characteristics occur over the area; the certainty factor computes the relative probabilities for various vulnerability states within a county and the coverage factor which elucidates the fraction of a specific vulnerability state present in each county. The coupling of rough sets with GIS is particularly advantageous to cluster counties exhibiting similar vulnerability characteristics and to obtain other related insights. The application of the approach indicates that the groundwater vulnerability exhibits greater variability along the coast than in the interior sections of the area. The shallow aquifer in Aransas, DeWitt, Goliad and Gonzales counties is the most vulnerable, while the aquifer in Duval, Jim Wells, Karnes, Live Oak, Nueces and San Patricio is less vulnerable. This approach should prove useful to regional planners and environmental managers entrusted with the protection of groundwater resources.     

Porphyry copper potential mapping using the weights of evidence model in a GIS,northern Shahr e Babak,Iran

A variety of spatial geological data were compiled, evaluated and integrated to produce a potential map for porphyry copper deposits in the northern Shahr e Babak, Iran, within a total area of approximately 408 km². Remotely sensed data including LANDSAT Thematic Mapper were used to create the hydrothermal alteration haloes around intrusive bodies. Geological data, such as exposed granitic to intermediate intrusions, and part of the lineaments were extracted from available geological maps. Aeromagnetic data were also used to extract magnetic anomalies and extra lineaments. The Conditional Independence test was carried out on five binary maps representing diagnostic deposit recognition criteria, and four of them were then integrated using a weights of evidence model. The procedure generated a posterior probability map identifying favourable areas for porphyry copper deposits. The final map highlights the most important known copper deposits in high favourability domains. Some new target areas are also located in the favourability map and warrant further investigation.     

ORACLE空间数据库的对象-关系模式初探——兼议关系数据库和面向对象数据库在GIS中的应用

传统的关系数据库在GIS的应用中主要存在以下问题: 除数据类型简单, 不能很好地表达非结构化数据外, 也难以表示GIS中具有复杂结构的数据; 关系模型简单, 不能表达数据之间的层次, 继承、聚合、泛化或特化等在GIS广泛使用的关系; 与数据操纵语言如SQL和通用程序设计语言, 特别是目前流行的面向对象设计语言之间失配.采用面向对象技术可以较好地解决上述问题.ORACLE的空间数据库在传统的关系数据库上进行了面向对象的扩展, 即所谓对象-关系模式, 其核心在于增加了名为SDO-GEOMETRY的对象数据类型, 用于存储几何实体.ORACLE的空间数据库的应用示例表明: 以面向对象的形式表示空间数据比之于关系数据库中存放大量无意义的坐标有着很大的优势, 同时, 它在复合对象的表达方面, 在对于空间关系的处理方面都非常有效      

An assessment of the risk associated with urban development in the Thiaroye area (Senegal)

Water quality data from 56 wells, aquifer characteristics, soil types and land use in the city suburb of Dakar were compared to assess the effects of land use on the Thiaroye groundwater quality. The study area encompassed an unsewered densely populated zone, agricultural land, low density villages, and undeveloped land located in the sand dunes. A method similar to GIS technologies was applied to evaluate the degree of vulnerability of the different parts of the aquifer in relation to urban development, land use and aquifer characteristics. The aquifer parameters (hydraulic conductivity, groundwater level depth, recharge, soil type) were re-evaluated qualitatively into three class rankings (high, moderate and low), depending on the likelihood for contaminants reaching the water table, then combined using the two matrix Boolean logic based approaches to identify the nine classes of vulnerability assessed in the aquifer domain. An attempt was made to explain the distribution of nitrate concentration with the assessed vulnerability. In the area assessed, in the densely populated zone running from Pikine, to Thiaroye and Yeumbeul, very high nitrate concentrations correspond with the highest vulnerability index (H1). Nitrate contamination in this area is a consequence of point-source seepage from individual septic systems improperly built in this area. In the eastern part of the aquifer, high nitrate concentrations at Deni B. Ndao, Mbawane and Golam localities coincide with a moderate vulnerability assessment. The major source of nitrate in these areas is induced by agricultural activities.     

Application of Remote Sensing in Flood Management with Special Reference to Monsoon Asia: A Review

The conventional means to record hydrological parameters of aflood often fail to record an extreme event. Remote sensingtechnology along with geographic information system (GIS)has become the key tool for flood monitoring in recent years.Development in this field has evolved from optical to radarremote sensing, which has provided all weather capabilitycompared to the optical sensors for the purpose of flood mapping.The central focus in this field revolves around delineation of floodzones and preparation of flood hazard maps for the vulnerable areas.In this exercise flood depth is considered crucial for flood hazardmapping and a digital elevation model (DEM) is considered to bethe most effective means to estimate flood depth from remotelysensed or hydrological data. In a flat terrain accuracy of floodestimation depends primarily on the resolution of the DEM. Riverflooding in the developing countries of monsoon Asia is very acutebecause of their heavy dependence on agriculture but any floodestimation or hazard mapping attempt in this region is handicappedby poor availability of high resolution DEMs. This paper presents areview of application of remote sensing and GIS in flood managementwith particular focus on the developing countries of Asia.