A geographical similarity-based sampling method of non-fire point data for spatial prediction of forest fires

Understanding the mechanisms and risks of forest fires by building a spatial prediction model is an important means of controlling forest fires.Non-fire point data are important training data for constructing a model,and their quality significantly impacts the prediction performance of the model.However,non-fire point data obtained using existing sampling methods generally suffer from low representativeness.Therefore,this study proposes a non-fire point data sampling method based on geographical similarity to improve the quality of non-fire point samples.The method is based on the idea that the less similar the geographical environment between a sample point and an already occurred fire point,the greater the confidence in being a non-fire point sample.Yunnan Province,China,with a high frequency of forest fires,was used as the study area.We compared the prediction performance of traditional sampling methods and the proposed method using three commonly used forest fire risk prediction models:logistic regression(LR),support vector machine(SVM),and random forest(RF).The results show that the modeling and prediction accuracies of the forest fire prediction models established based on the proposed sampling method are significantly improved compared with those of the traditional sampling method.Specifically,in 2010,the modeling and prediction accuracies improved by 19.1%and 32.8%,respectively,and in 2020,they improved by 13.1%and 24.3%,respectively.Therefore,we believe that collecting non-fire point samples based on the principle of geographical similarity is an effective way to improve the quality of forest fire samples,and thus enhance the prediction of forest fire risk.

DEVELOPMENT OF A GIS DATA MODEL WITH SPATIAL,TEMPORAL AND ATTRIBUTE COMPONENTS BASED ON OBJECT-ORIENTED APPROACH

This paper presents a conceptual data model, the STA-model, for handling spatial, temporal and attribute aspects of objects in GIS. The model is developed on the basis of object-oriented modeling approach. This model includes two major parts: (a) modeling the signal objects by STA-object elements, and (b) modeling relationships between STA-objects. As an example, the STA-model is applied for modeling land cover change data with spatial, temporal and attribute components.

Full feature data model for spatial information network integration

In allusion to the difficulty of integrating data with different models in integrating spatial information, the characteristics of raster structure, vector structure and mixed model were analyzed, and a hierarchical vector-raster integrative full feature model was put forward by integrating the advantage of vector and raster model and using the object-oriented method. The data structures of the four basic features, i.e. point, line, surface and solid, were described. An application was analyzed and described, and the characteristics of this model were described. In this model, all objects in the real world are divided into and described as features with hierarchy, and all the data are organized in vector. This model can describe data based on feature, field, network and other models, and avoid the disadvantage of inability to integrate data based on different models and perform spatial analysis on them in spatial information integration.

AN INTEGRATED DATA MODEL IN THREE DIMENSIONAL GIS

The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.

Modeling data quality for risk assessment of GIS

This paper presents a methodology to determine three data quality (DQ) risk characteristics: accuracy, comprehensiveness and nonmembership. The methodology provides a set of quantitative models to confirm the information quality risks for the database of the geographical information system (GIS). Four quantitative measures are introduced to examine how the quality risks of source information affect the quality of information outputs produced using the relational algebra operations Selection, Projection, and Cubic Product. It can be used to determine how quality risks associated with diverse data sources affect the derived data. The GIS is the prime source of information on the location of cables, and detection time strongly depends on whether maps indicate the presence of cables in the construction business. Poor data quality in the GIS can contribute to increased risk or higher risk avoidance costs. A case study provides a numerical example of the calculation of the trade-offs between risk and detection costs and provides an example of the calculation of the costs of data quality. We conclude that the model contributes valuable new insight.

Unified Data Model of Urban Air Pollution Dispersion and 3D Spatial City Model:Groundwork Assessment towards Sustainable Urban Development for Malaysia

Understanding the behavior of urban air pollution is important en route for sustainable urban development (SUD). Malaysia is on its mission to be a developed country by year 2020 comprehends dealing with air pollution is one of the indicators headed towards it. At present monitoring and managing air pollution in urban areas encompasses sophisticated air quality modeling and data acquisition. However, rapid developments in major cities cause difficulties in acquiring the city geometries. The existing method in acquiring city geometries data via ground or space measurement inspection such as field survey, photogrammetry, laser scanning, remote sensing or using architectural plans appears not to be practical because of its cost and efforts. Moreover, air monitoring stations deployed are intended for regional to global scale model whereby it is not accurate for urban areas with typical resolution of less than 2 km. Furthermore in urban areas, the pollutant dispersion movements are trapped between buildings initiating it to move vertically causing visualization complications which imply the limitations of existing visualization scheme that is based on two-dimensional (2D) framework. Therefore this paper aims is to perform groundwork assessment and discuss on the current scenario in Malaysia in the aspect of current policies towards SUD, air quality monitoring stations, scale model and detail discussion on air pollution dispersion model used called the Operational Street Pollution Model (OSPM). This research proposed the implementation of three-dimensional (3D) spatial city model as a new physical data input for OSPM. The five Level of Details (LOD) of 3D spatial city model shows the scale applicability for the dispersion model implementtation. Subsequently 3D spatial city model data commonly available on the web, by having a unified data model shows the advantages in easy data acquisition, 3D visualization of air pollution dispersion and improves visual analysis of air quality monitoring in urban areas.

A DESIGN OF THREE-DIMENSIONAL SPATIAL DATA MODEL AND ITS DATA STRUCTURE IN GEOLOGICAL EXPLORATION ENGINEERING

The key to develop 3-D GISs is the study on 3-D data model and data structure. Some of the data models and data structures have been presented by scholars. Because of the complexity of 3-D spatial phenomenon, there are no perfect data structures that can describe all spatial entities. Every data structure has its own advantages and disadvantages. It is difficult to design a single data structure to meet different needs. The important subject in the3-D data models is developing a data model that has integrated vector and raster data structures. A special 3-D spatial data model based on distributing features of spatial entities should be designed. We took the geological exploration engineering as the research background and designed an integrated data model whose data structures integrats vector and raster data byadopting object-oriented technique. Research achievements are presented in this paper.

Design of Data Model for Urban Transport GIS

Constructing the data model for public transportation by integrating the spatial and the non-spatial information, is the basis of reasonable plan and effective management of urban public transport. This paper presents a transit data model based on geographic information systems (GIS) technology, which utilizes arc-node networks, and manages the foundational bus data with point, link, polygon and record features. In this model, a transport network is generated and maintained in a dynamic manner, and hence supports planning, construction, management, operation and optimization functions for transit facilities and routes, as well as day-to-day transactions. Public transportation GIS established on this model foundation will remarkably upgrade the construction level and the urban service ability.

Design and Key Technology of Gardening Information Management System Based on Data Center

To provide scientific management basis for the garden planning, project construction, maintenance, social service, this paper prompted that the urban gardening administration sectors need to construct gardening information management system. On the basis of fully requirements analysis of gardening sectors, this paper discussed the key technology for system construction. It also proposed to flexibly and smartly build up the system by using the secondary development design environment and running environment based on data center integration development platform. This system greatly helps the daily management and plays very important role in improving urban ecological environment and investment environment.

Water Runoff Estimation Using Geographical Information System (GIS) for Alrakhmah Basin Valley Northeast of Iraq

The lack of water resources in many regions is the main challenge for the human being and to extended investigations. Water resources controlling and management is essential in the areas depending on the seasonal rainfall. This research aims to estimate the surface water runoff for Basin of Alrakhmah Valley located in the southwestern part of Kirkuk Province in northeastern of Iraq. Analyzing of Spatial data and Digital Elevation Model (DEM) data has been conducted using Geographic Information System (GIS) to estimate the hydrological properties for the watershed valley with 158.5 km2 surface area. The results showed that watershed valley type is from the fifth rank with a longitudinal shape and topography percentage of 0.568. The watershed textures found to be 3.24 and the drain density 1.5 at 3.49 river branching. Finally, the annual estimated surface water retreat according to the morpho-hydro climatic elements found to be 0.01286233 milliard cubic meter.

基于GeoDatabase和ArcSDE的湿地GIS数据库技术研究与应用实例

以松嫩湿地为背景,介绍了GeoDatabase结合ArcSDE技术建立G IS数据库的方法,详细阐述了如何实现属性数据和空间数据一体化存储的理论细节,在此基础上提出了两者的改进连接方案;同时将该方法与传统的G IS数据存储方式相比较来说明其先进性。进而通过实例证明了此数据库技术在应用系统开发中的实用性。

Environmental Analysis Using Integrated GIS and Spatial Configurations in Israel

The scope for environmental analysis constitutes a critical factor in recent times, yet demanding importance due to the concerns of environmental sustainability. The study aims at analysing the prospects of implementing an integrated GIS and spatial configuration for environment analysis in Israel. The study adopts an empirical study design to consider the multi-dimensional utilisation of an integrated GIS and spatial configuration for environment analysis. The study considers the materials and methods of the GIS system modelling as well, consisting of satellite imagery, GPS-based location identification, Esri ArcGIS, CyberGIS, and BIM integration to present a comprehensive system for the environmental analysis of Israel. The results of the study indicate that the threats of natural disasters and climate change can be identified based on the synergy of spatial data within an integrated GIS modelling. In many cases, it is also used in collaboration with a BIM to ensure that planning and decision-making processes are sustainable, economically beneficial and environmentally considered. Thus, it is concluded that environmental analysis through the projection of visually represented satellite imagery within an integrated GIS with spatial configurations in Israel can minimise the conflicts between the infrastructural designs, human activities, and environmental sustainability.

Constructing a raster-based spatio-temporal hierarchical data model for marine fisheries application

Marine information has been increasing quickly. The traditional database technologies have disadvantages in manipulating large amounts of marine information which relates to the position in 3-D with the time. Recently, greater emphasis has been placed on GIS （geographical information system）to deal with the marine information. The GIS has shown great success for terrestrial applications in the last decades, but its use in marine fields has been far more restricted. One of the main reasons is that most of the GIS systems or their data models are designed for land applications. They cannot do well with the nature of the marine environment and for the marine information. And this becomes a fundamental challenge to the traditional GIS and its data structure. This work designed a data model, the raster-based spatio-temporal hierarchical data model （RSHDM）, for the marine information system, or for the knowledge discovery fi＇om spatio-temporal data, which bases itself on the nature of the marine data and overcomes the shortages of the current spatio-temporal models when they are used in the field. As an experiment, the marine fishery data warehouse （FDW） for marine fishery management was set up, which was based on the RSHDM. The experiment proved that the RSHDM can do well with the data and can extract easily the aggregations that the management needs at different levels.

基于GIS+BIM的地铁工程实景三维可视化关键技术及应用

针对地铁工程项目可视化管理中存在的模型精细化不足、数据集成与展示不充分及真实性欠缺等问题,本研究提出了利用GIS和BIM技术作为解决方案,提升地铁工程实景三维建设的效果。首先研究构建了地铁工程实景三维平台的建设框架,分析了数据集成与融合、动态层次加载、模型轻量化与显示等关键技术。随后以深圳地铁14号线工程为案例,进行了实景三维可视化平台的建设与功能应用。案例涵盖了工程建设管理图、空间分析可视化、多视角场景漫游及BIM可视化与属性查询等内容,实现了地铁工程项目多源异构数据与模型的集成,提供了多尺度的实景三维可视化展示,为项目管理与决策提供了有力支持。

GIS在城镇燃气管网中的关键技术及应用

燃气是人们生产和生活中不可或缺的要素,而燃气输配运行过程中燃气管网在燃气系统的设计、建设和维护中扮演着至关重要的角色。城镇燃气的高速发展,对燃气管网的运行管理提出了更高的要求,对精细化、科学化、规范化管理需求也不断提升。为满足这些需求,地理信息系统(Geographic Information System,GIS)在城镇燃气地下管网中得到了广泛应用。运用空间数据转换处理系统FME(Feature Manipulate Engine)进行数据建库和数据转换,ArcMAP用于燃气管道设施空间数据处理,GeoPandas结合Sklearn程序包实现巡检网格制作及动态分析可实现地下燃气管道的精细化巡检,进一步提升输配管道设施的运行管理水平,降低事故发生,提高管网运行效率和安全性。

RESEARCH ON THE SECURITY OF NATIONAL GEOSPATIAL DATA CLEARINGHOUSE BASED ON ASP

On the basis of the authors’ experiences of setting up an NGDC Web site,this paper attempts to present some significant aspects about the security of NGDC based on ASP.They include data storing,database maintenance,new technical support and so on.Firstly,this paper discusses how to provide the security of data which is saved in the hosts of NGDC.The security model of "Networks_DB Server_DB_DB Object" is also presented.In Windows NT Server,Internet Information Server (i.e.,IIS) is in charge of transferring message and the management of Web sites.ASP is also based on IIS.The advantages of virtual directory technique provided by IIS are emphasized. An NGDC Web site,at the Research Center of GIS in Wuhan Technical University of Surveying and Mapping is also mentioned in this paper.Because it is only an analoge used for case study,the transmission of digital spatial products is not included in the functions in this NGDC Web site.However,the management of spatial metadata is more important and some functions of metadata query are implemented in it.It is illustrated clearly in the functional diagram of the NGDC Web site.

The Geographic Information Grid System Based on Mobile Agent

We analyze the deficiencies of current application systems, and discuss the key requirements of distributed Geographie Information serviee （GIS）, We construct the distributed GIS on grid platform. Considering the flexibility and efficiency, we integrate the mobile agent technology into the system. We propose a new prototype system, the Geographic Information Grid System （GIGS） based on mobile agent. This system has flexible services and high performance, and improves the sharing of distributed resources. The service strategy of the system and the examples are also presented.

Utilization of Open Source Spatial Data for Landslide Susceptibility Mapping at Chittagong District of Bangladesh—An Appraisal for Disaster Risk Reduction and Mitigation Approach

Since creation of spatial data is a costly and time consuming process, researchers, in this domain, in most of the cases rely on open source spatial attributes for their specific purpose. Likewise, the present research aims at mapping landslide susceptibility at the metropolitan area of Chittagong district of Bangladesh utilizing obtainable open source spatial data from various web portals. In this regard, we targeted a study region where rainfall induced landslides reportedly causes causalities as well as property damage each year. In this study, however, we employed multi-criteria evaluation (MCE) technique i.e., heuristic, a knowledge driven approach based on expert opinions from various discipline for landslide susceptibility mapping combining nine causative factors—geomorphology, geology, land use/land cover (LULC), slope, aspect, plan curvature, drainage distance, relative relief and vegetation in geographic information system (GIS) environment. The final susceptibility map was devised into five hazard classes viz., very low, low, moderate, high, and very high, representing 22 km2 (13%), 90 km2 (53%);24 km2 (15%);22 km2 (13%) and 10 km2 (6%) areas respectively. This particular study might be beneficial to the local authorities and other stake-holders, concerned in disaster risk reduction and mitigation activities. Moreover this study can also be advantageous for risk sensitive land use planning in the study area.

煤矿GIS一张图快速构建平台研究

目前,煤矿使用的工程专题地图基本都是CAD制图,高效提取CAD图件中的数据并快速组织成地理信息系统(GIS)服务,进而支持矿井空间对象创建和业务属性扩展,集成安全生产实时数据,是构建煤矿GIS一张图的关键。基于ArcGIS平台将CAD图件转为GIS服务的方法实现过程较为繁琐,且ArcGIS平台成本较高,无法较好地跨平台运行。针对该问题,设计了一种煤矿GIS一张图快速构建平台。该平台包括CAD图件管理、地图服务发布、专题地图管理3大功能模块:CAD图件管理模块用于图件基础信息管理和状态跟踪,地图服务发布模块用于地图打包发布和在线预览,专题地图管理模块用于地图服务管理、矿井对象创建及属性扩展。基于开放设计联盟(ODA)的Teigha for Java SDK实现CAD图件全要素精确识别与快速准确提取;通过构建基于GIS数据特征的煤矿CAD图件数据分层描述模型,实现了CAD图件全要素数据快速存储;按照面向对象设计思路,开发了Spring Cloud框架下的Web端煤矿CAD图件数据集存储接口及专题地图服务发布平台,实现了煤矿GIS一张图快速构建。以某煤矿采掘工程平面图为例,分别采用传统方法和快速构建平台进行煤矿GIS一张图的构建,对比结果表明,快速构建平台可大幅提高煤矿GIS一张图的构建效率,为煤矿智能化建设提供时空数字底座。

Object-Based Analysis of Multispectral RS Data and GIS for Detection of Climate Change Impact on the Karakoram Range Northern Pakistan

Changing climate has a great impact on northern area of Pakistan＇s environment and is more prone to environmental changes impacts than rest of the country due to its high elevation. However, melting glaciers effect not only the local environment but also the whole country with frequent and heavy floods. Remote sensing （RS） from Satellites and Airplanes used in Geographical Information Systems （GIS） are technologies that can aid in understanding the on-going environmental processes. Furthermore, help researchers to observe, understand, forecast and suggest response to changes that occur. It can be natural disasters or man-made disasters and human induced factors. Still analysis accuracy issues play a vital role for the formulation of any strategy. To achieve better results, object based analysis methods have been tested. Various algorithms are developed by the analysts to calculate the magnitude of land cover changes. However, they must be evaluated for each environment that is under observation as mountainous areas. Here were object-based methods evaluated in comparison with pixel based. Landslides, soil moisture, soil permeability, snow cover and vegetation cover can be effectively monitored by those methods.