Desktop GIS Research Articles

ВИКОРИСТАННЯ ВІДКРИТИХ ГЕОІНФОРМАЦІЙНИХ СИСТЕМ У ПІДГОТОВЦІ ФАХІВЦІВ З КОМП'ЮТЕРНИХ НАУК

The article is devoted to the issue of using open geographic information systems in training of the students majoring in «Computer Sciences» particularly in the framework of «Geographic information systems» discipline. The objectives, the task and the place of "Geographic information systems" discipline in the system of training the students of IT specialties have been determined. The analysis of curricula of several domestic higher education institutions that provide training in computer sciences has shown the prevailing orientation of using the proprietary geoinformation systems and technologies in the educational process. In the authors’ opinion, it sufficiently narrows the didactic potential of the «Geographic information systems» discipline reducing the level of its information saturation. It is proposed to use open geo-information systems in the learning process, which will create conditions for more qualitative and productive students’ understanding of creation, operation and implementation of geo-information systems to address real-world applied issues. A comparative analysis of the most worldwide open-source desktop geographic information systems has been conducted in order to identify their potential for the use of training. The directions of using open geo-information systems from the point of view of organizational process as well as from the perspective of training efficiency are described. The advantages and disadvantages of leveraging open geographic information systems, namely: QGIS, GRASS GIS, Whitebox GAT, Saga GIS, gvSiG, ILWIS, uDIG, MapWindow GIS for the teaching of the «Geographic Information Systems» discipline have been determined. The authors recommend to use such open geographic information systems as uDIG, QGIS, Whitebox GAT in the teaching of the university discipline at the start of educational courses; the choice of geographic information systems for senior students is limited solely to the goals and objectives set by the university teachers to future professionals in computer sciences.

OPEN SOURCE SOFTWARE AND OPEN EDUCATIONAL MATERIAL ON LAND COVER MAPS INTERCOMPARISON AND VALIDATION

Abstract. Land Cover (LC) maps represent key resources to understand, model and address many global and local dynamics affecting our planet. They are usually derived from the classification of satellite imagery, after which a validation or intercomparison process is performed to assess their accuracy. This paper presents the project “Capacity Building for High-Resolution Land Cover Intercomparison and Validation”, an educational initiative funded by the International Society for Photogrammetry and Remote Sensing (ISPRS) and mainly targeting developing countries. First, with the help of two open surveys, an analysis of the state of the art was performed which assessed the overall good awareness on LC maps and the needs and requirements for validating and comparing them, as well as the rich availability of educational material on this topic. The second task, currently under finalization, is the development of new educational material, based on open source software and released under an open access license, consisting of: an introduction to the GlobeLand30 (GL30) LC map and its online platform; a desktop GIS procedure showing two use cases on GL30 validation; and an application to collect LC data on the field to be used for validation. Finally, this educational material will be tested in practice in three workshops during the second half of the project, two of which held in developing countries: Dar es Salaam, Tanzania and Nairobi, Kenya.

Competing space and place identity with landscape change analysis using Web GIS through Singapore historical maps (1828–2015)

The investigation of historical maps is fundamental to understanding the dynamics of landscape changes. In this study, we propose Web GIS tools as a way to compare historical maps efficiently for knowledge production. A key impetus of this article is to contribute to the ongoing efforts to broaden the appeal of ‘mixed‐methods research’ by bridging the epistemological and methodological gaps between GIS and qualitative methodologies in knowledge production. This article proposes a new visualization method for historical landscape change analysis by comparing multiple maps simultaneously with the mash‐up of Web GIS. Based on the analysis of exterior facts represented on the maps, four developmental footprints were investigated, namely, surviving place identity, disappeared place identity replaced by new identity, waning place identity overlapped with new identity, and waning identity by disconnected spatial relationships. To this end, the study argues that Web GIS applications have more potential in spatial knowledge production than traditional desktop GIS.

GLOBE BASED 3D GIS SOLUTIONS FOR VIRTUAL HERITAGE

Abstract. During the last years, many solutions have been proposed for 3D Virtual Heritage representations. Recently, also new technologies for online gaming evolved, based on javascript libraries (WebGL), used to create and publish virtual interactive environments. They are based on recent Web browser’s functionalities, surpassing some limitations of VRML technologies. On the side of geospatial information, technology has evolved from desktop GIS to 2D WebGIS and globe applications. The use of globe applications is, today, very diffused due to its immediate and at the same time impressive representation of the earth surface and territories. These technologies have been, also, applied to Virtual Heritage 3D reconstructions, to improve the fruition of Cultural Heritage (CH), with the achievement of interesting results. The topic of this paper is the experimentation on the fusion between globe based and gaming technologies (in our case WebGL) that allow achieving a more user-centric and powerful solution useful for publishing 3D geospatial information of CH on Web. This choice allows obtaining GIS oriented 3D models, typical of globe applications, and, at the same time, a more immersive exploration of CH and its surrounding environment. In particular, it also gives complementary text and multimedia information on the history, architectural features of each cultural good, based on querying of semantic information. The test field of the research is the construction of the 3D GIS virtual globe model of the Manfredonic Castle of Mussomeli (Sicily-Italy), developed for PON-NEPTIS EU Project, to compare open-source technologies and commercial proprietary applications.

Application of the Spatial Database for Shoreline Change Analysis and Visualisation: Example from the Western Polish Coast, Southern Baltic Sea

Abstract The main aim of the study was to introduce a spatial database application for the estimation of changes in shoreline position. The open-source PostgreSQL database system with the PostGIS spatial extension was used as the data store for digitalised shorelines. The solution to calculations of the shoreline changes was based on the functions written in the PL/SQL language and geospatial functions provided by the PostGIS extension. The traditional baseline and transects method was used to quantify the distances and rate of shoreline movement. Outputs of the calculations were stored in the database table and simply visualised using graphical functions in the R software environment or in GIS Desktop software. The advantage of presented method is the application of SQL language in the analysis of the relation between the geometry of shorelines stored in the database table, which, compared to other similar solutions, gives the user fully open, simple analytical code and enable selecting custom parameters of analysis, modifying code and performing additional calculations.

Managing In-Library Use Data: Putting a Web Geographic Information Systems Platform through its Paces

Web Geographic Information System (GIS) platforms have matured to a point where they offer attractive capabilities for collecting, analyzing, sharing, and visualizing in-library use data for space-assessment initiatives. As these platforms continue to evolve, it is reasonable to conclude that enhancements to these platforms will not only offer librarians more opportunities to collect in-library use data to inform the use of physical space in their buildings, but also that they will potentially provide opportunities to more easily share database schemas for defining learning spaces and observations associated with those spaces. This article proposes using web GIS, as opposed to traditional desktop GIS, as an approach for collecting, managing, documenting, analyzing, visualizing, and sharing in-library use data and goes on to highlight the process for utilizing the Esri ArcGIS Online platform for a pilot project by an academic library for this purpose.

Crime Mapping and Law Enforcement Scope and Applications

Though computer mapping has been used as a tool for law enforcement since the 1970s, the use of GIS (Geographic Information System ) has increased particularly in the last few years with the availability of more effective and user-friendly desktop GIS applications. GIS is an umbrella term used to identify a set of procedures and protocols involving hardware/software for organizing storing, retrieving, analyzing and displaying data that has a space dimension.

Capacity estimation of small surface water bodies using RS and GIS

Surface water bodies are the major source for irrigation in India. Information on surface water bodies such as water spread area, volume of water stored in a water body is useful for understanding the availability of water resources for the crop season in a river basin/sub basin. The study extensively used satellite based techniques for the estimation of surface water spread at regional level and at temporal scale to facilitate mapping, monitoring visualization of the dynamics unlike conventional methods. Geospatial database on water bodies information has been created for the study area Krishna middle sub basin. The study considers only water bodies where water is stored for irrigation purpose such as reservoirs, tanks, ponds, etc excluding rivers. Study is focused on use of RS and GIS techniques with extensive use of Image processing and GIS software like ERDAS Imagine, ARC Desktop GIS and analyses the spatio-temporal water body layers. Quantitative estimates on WSA under water bodies are worked for analyzing inter/intra seasonal/annual analysis. The present study has brought out geospatial database and provided scope for sub regional/regional analysis. Estimation of regional surface water storage is estimated with separate methodology for larger and smaller water bodies. This is demonstrated within a sub basin namely Krishna middle sub basin. Storage in larger water bodies is estimated by developing satellite based Area-Capacity curves related to Elevation values on the date satellite data acquisition. Storage in smaller water bodies is estimated with the help a methodology frame work developed in this study using digital elevation models, stream order and relating to the extensive observations made on elevation difference between upstream and downstream of water bodies. The study has brought out suitable spatio-temporal information of water bodies useful for analyzing operational issues related to water resources availability. The information generated can be made use for web based regional analysis and for public domain with suitable visualization tools.

Evaluating Spatio-temporal Data Models for Trajectories in PostGIS Databases

Research in transport, ecology, health and other fields stands to profit from an improved understanding of movement. As movement data availability improves, the need for appropriate movement data analysis increases. However, the limited support for modelling moving objects in GIS hampers data exploration and analysis. This paper discusses trajectory data models and their implementation in the open-source spatial database system PostGIS. We quantify the difference in performance between PostGIS default trajectory support, dedicated trajectory data models, and commonly used point-based data models. To the best of our knowledge, this is the first paper to evaluate PostGIS default trajectory support and compare it to a proposed dedicated trajectory data type from the literature. Our experiments include computing trajectory duration and length, temporal and spatial filters, extracting positions at a certain time, and visualizing trajectories in desktop GIS. We also discuss the limitations of, and potential for, contextual trajectories and moving area object trajectories. Our results show that PostGIS functions for moving point object trajectories are fast, reduce query complexity, and provide good indexing integration, especially concerning multi-dimensional indices; the results also reveal that trajectory data models outperform commonly used point-based data models.

Research on application of GIS and GPS in inspection and management of city gas pipeline network

To solve the problems existing in the current Gas Company patrol management, such as inaccurate attendance, whether or not the patrol personnel exceed the scope of patrol inspection. This paper Proposed that we apply the SuperMap iDeskTop 8C plug-in desktop GIS application and development platform, the positioning function of GPS and the data transmission function of 3G/4G/GPRS/Ethernet to develop a gas pipeline inspection management system. We build association between real-time data, pipe network information, patrol data, map information, spatial data and so on to realize the bottom data fusion, use the mobile location system and patrol management client to achieve real-time interaction between the client and the mobile terminal. Practical application shows that the system has completed the standardized management of patrol tasks, the reasonable evaluation of patrol work and the maximum utilization of patrol resources.

A model for locating fodder shrub plantations sites in the Jordanian badiyah

We developed a GIS desktop model to accurately locate and map prospective areas for sustainable establishment and production of Atriplex plantations and other fodder shrubs in the desert in the north-eastern Jordanian Badiyah. The aim is to provide a tool to assist managers, local communities and development projects in Mediterranean arid and semi-arid rangelands. The model uses freely available data and GIS layers of current land use, land cover, settlement location, soil information, and derivatives from a digital elevation model to provide critical locations of drainage lines and to calculate Areas of Accumulated Water from concentrated runoff. The model identified, accurately located and mapped ~4500 ha (1.44% of the test zone) as technically appropriate for potential shrub plantations sites. The final site map must be field-checked and validated with the local communities and authorities. Our model has potential for wide application over arid and semi-arid Mediterranean rangelands from Morocco to Pakistan, with local adjustment of our parameters and rules. The model considerably reduces the risk and costs of fodder plantation establishment operations, thus increasing the feasibility of efforts to maximise fodder shrub establishment, survival and production.

The application of near-automated georeferencing technique to a strip of historic aerial photographs in GIS

PurposeThe purpose of this paper is to describe the procedure for near-automation of the most commonly used manual georeferencing technique in a desktop GIS environment for historic aerial photographs strip in library archives.Design/methodology/approachMost of the archived historic aerial photography consists of series of aerial photographs that overlap to some extent, as the optimal overlap ratio is known as 60 percent by photogrammetric standard. Therefore, conjugate points can be detected for the overlapping area. The first image was georeferenced manually by six-parameter affine transformation using 2013 National Agriculture Imagery Program images as ground truths. Then, conjugate points were detected in the first and second images using Speeded Up Robust Features and Random Sample Consensus. The ground space coordinates of conjugate points were estimated using the first image’s six parameters. Then the second image’s six parameters were calculated using conjugate points’ ground space coordinates and pixel coordinates in the second image. This procedure was repeated until the last image was georeferenced. However, error accumulated as the number of photographs increased. Therefore, another six-parameter affine transformation was implemented using control points in the first, middle, and last images. Finally, the images were warped using open source GIS tools.FindingsThe result shows that historic aerial strip collections can be georeferenced with far less time and labor using the technique proposed compared with the traditional manual georeferencing technique in a desktop GIS environment.Research limitations/implicationsThe suggested approach will promote the usage of historic aerial photographs for various scientific purposes including land use and land cover change detection, soil erosion pattern recognition, agricultural practices change analysis, environmental improvement assessment, and natural habitat change detection.Practical implicationsMost commonly used georeferencing procedures for historic aerial photographs in academic libraries require significant time and effort for manual measurement of conjugate points in the object images and the ground truth images. By maximizing the automation of georeferencing procedures, the suggested approach will save significant time and effort of library workforce.Social implicationsWith the suggested approach, large numbers of historic aerial photographs can be rapidly georeferenced. This will allow libraries to provide more geospatial data to scientific communities.Originality/valueThis is a unique approach to rapid georeferencing of historic aerial photograph strips.

LSIVIEWER 2.0 – A CLIENT-ORIENTED ONLINE VISUALIZATION TOOL FOR GEOSPATIAL VECTOR DATA

Abstract. Geospatial data visualization systems have been predominantly through applications that are installed and run in a desktop environment. Over the last decade, with the advent of web technologies and its adoption by Geospatial community, the server-client model for data handling, data rendering and visualization respectively has been the most prevalent approach in Web-GIS. While the client devices have become functionally more powerful over the recent years, the above model has largely ignored it and is still in a mode of serverdominant computing paradigm. In this paper, an attempt has been made to develop and demonstrate LSIViewer – a simple, easy-to-use and robust online geospatial data visualisation system for the user’s own data that harness the client’s capabilities for data rendering and user-interactive styling, with a reduced load on the server. The developed system can support multiple geospatial vector formats and can be integrated with other web-based systems like WMS, WFS, etc. The technology stack used to build this system is Node.js on the server side and HTML5 Canvas and JavaScript on the client side. Various tests run on a range of vector datasets, upto 35 MB, showed that the time taken to render the vector data using LSIViewer is comparable to a desktop GIS application, QGIS, over an identical system.

GPU-Accelerated Rendering Methods to Visually Analyze Large-Scale Disaster Simulation Data

Emerging methodologies for natural hazard risk assessments involve the execution of a multitude of different interacting simulation models that produce vast amounts of spatio-temporal datasets. This data pool is further enlarged when such simulation results are post-processed using GIS operations, for example to derive information for decision-making. The novel approach presented in this paper makes use of the GPU-accelerated rendering pipeline to perform such operations on-the-fly without storing any results on secondary memory and thus saving large amounts of storage space. Particularly, algorithms for three frequently used geospatial analysis methods are provided, namely for the computation of difference maps using map algebra and overlay operations, distance maps and buffers as examples for proximity analyses as well as kernel density estimation and inverse distance weighting as examples for statistical surfaces. In addition, a visualization tool is presented that integrates these methods using a node-based data flow architecture. The application of this visualization tool to the results of a real-world risk assessment methodology used in civil engineering shows that the memory footprint of post-processing datasets can be reduced at the order of terabytes. Although the technique has several limitations, most notably the reduced interoperability with conventional analysis tools, it can be beneficial for other use cases. When integrated into desktop GIS applications, for example, it can be used to quickly generate a preview of the results of complex analysis chains or it can reduce the amount of data to be transferred to web or mobile GIS applications.

MapMosaic: dynamic layer compositing for interactive geovisualization

ABSTRACTGIS software applications and other mapping tools enable users to correlate data from multiple layers and gain insight from the resulting visualizations. However, most of these applications only feature basic, monolithic layer compositing techniques. These techniques do not always support users effectively in their tasks, as we observed during interviews with GIS experts. We introduce MapMosaic, a novel approach based on dynamic visual compositing that enables users to interactively create and manipulate local composites of multiple vector and raster map layers, taking into account the semantics and attribute values of objects and fields in the compositing process. We evaluate MapMosaic ’s interaction model against that of QGIS (a widely used desktop GIS) and MAPublisher (a professional cartography tool) using the ‘Cognitive Dimensions’ framework and through an analytical comparison, showing that MapMosaic ’s model is more flexible and can support users more effectively in their tasks. We also report on feedback obtained from experts, which further confirms the potential of this highly dynamic approach to map layer compositing.

Rule-based topology system for spatial databases to validate complex geographic datasets

A rule-based topology software system providing a highly flexible and fast procedure to enforce integrity in spatial relationships among datasets is presented. This improved topology rule system is built over the spatial extension Jaspa. Both projects are open source, freely available software developed by the corresponding author of this paper.Currently, there is no spatial DBMS that implements a rule-based topology engine (considering that the topology rules are designed and performed in the spatial backend). If the topology rules are applied in the frontend (as in many GIS desktop programs), ArcGIS is the most advanced solution. The system presented in this paper has several major advantages over the ArcGIS approach: it can be extended with new topology rules, it has a much wider set of rules, and it can mix feature attributes with topology rules as filters. In addition, the topology rule system can work with various DBMSs, including PostgreSQL, H2 or Oracle, and the logic is performed in the spatial backend.The proposed topology system allows users to check the complex spatial relationships among features (from one or several spatial layers) that require some complex cartographic datasets, such as the data specifications proposed by INSPIRE in Europe and the Land Administration Domain Model (LADM) for Cadastral data.

Development of Web GIS for information of renewable energy in Aceh Province after rehabilitation and reconstruction process

There are a lot of renewable energy potentials that is spread in numerous locations in Aceh Province. These potentials can be developed into energy source that can be utilized to fulfill the need of energy in the area. It is unfortunate that the information about the potentials is still hard to find, regardless the abundance of spatial data that were produced during the rehabilitation and reconstruction process, including data related to the renewable energy. Therefore, this research was conducted to develop an application of information technology, especially Web Geographic Information System (GIS) for renewable energy potential. The objective of this research was to fulfill the needs of relevant agencies for the Web GIS-based information technology applications to manage information on renewable energy potential in an interactive and integrated way. This research used components of Free Open Source System (FOSS) to develop a Web-based geospatial information technology application. The component consists of GeoServer as a GIS server, PostgreSQL as a geographic databases management system, QGIS as Desktop GIS for spatial data preparation and GeoExt as the framework in developing user interfaces for the Web GIS. The result of combining those components was a Web GIS that displayed areas with its renewable energy potential which was organized for each area along with legends for the map information. The Web GIS is equipped with search feature and tooltips function to select any areas and bring up detailed information of renewable energy potential of the area.

Development of a Mobile GIS Property Mapping Application using Mobile Cloud Computing

This study presents the development of a mobile GIS Property mapping application for use by local authorities in developing countries. Attempts to develop property mapping applications especially in developing countries have mostly used GIS desktop productivity software tools that required the digitization of property maps by highly skilled GIS experts. In addition, these applications lacked real time capture of attribute, spatial and image data of properties. A survey was conducted in the Kafue local authority to gather systems requirements for the mobile application. After design and modeling, the developed application was trialed in the field and 10 properties were mapped successfully. The software tools used in this study included Android Studio, Leaflet mapping library, Apache2 web server, PostgresSQL with PostGIS Extensions and OpenstreetMaps and MapBox mobile cloud computing mapping services. The hardware tools used included a laptop computer and a mobile phone running android operating system. The study showed that mobile property mapping applications can be developed by tapping into the computing resources provided by mobile cloud computing. The benefits of this model include real time complete property data capture and the use of non GIS experts in mapping projects.

Cambio Multitemporal De La Cobertura Vegetal Y Fragmentación En La Reserva Ecológica “Mache- Chindul” Ecuador

The "Mache-Chindul" -REMACH- Ecological Reserve is one of the 33 natural areas that make up the National System of Protected Areas - SNAP-, administered by the Ecuadorian government through the Ministry of Environment, MAE. This ecological reserve protects one of the few remnants of tropical dry Ecuador forest, as well as a variety of endemic species of flora and fauna, many of which are endangered, the study allowed us to determine the multitemporal cover change plant (natural forest, pasture and cultivated timberline) and fragmentation of forest area between 2002- 2012 with the implementation of programs GIS and ArcGIS Desktop 9.3 Er Mapper. Information of the study area was lifted from satellite Landsat 7 ETM (spatial resolution 30 m per pixel) to the same as a composition of pseudo color (RGB-431) and a classification applied supervised using the method of Minimum Distance. The ecological reserve has an area of 53,662 hectares of natural forest, equivalent to 44.7 % of total area, 23.1 % is regeneration or recovery of natural forest with an area of 27,707 hectares; the natural forest has undergone several interventions, considering the most affected and the peripheral area south of the rivet end, fragmentation was of 38,632 was equivalent to 32.2 % of the total area of the reserve, in the category of cultivated grass product the increase of the agricultural frontier and decreasing natural forest cover from the illegal extraction of wood, also the pressure from timber companies and colonization fronts, concerning the population index this has decreased from 5.71 to 5.39 hab / km2.

Exploiting a drainage database via internet

To manage the HCMC drainage system, the city’s Urban Drainage Company has been developing a desktop GIS based on ArcGIS software, ESRI. In this system, drainage database is organized into Geodatabase model and is stored in a server placed at the company headquarter. The company’s satellite offices can get access to the server’s database through a virtual private network. With this arrangement, investment cost will increase rapidly if the company is going to equip GIS software to workstation of every related staff. To avoid this investment burden problem, a WebGIS system has been developed based on ASP.NET framework of Microsoft, as well as the open source products Geoserver, and OpenLayers. With this webGIS, the company staff can access to drainage database from everywhere through the Internet by using just a normal web browser making requests for data through a standard web page. They can also carry out several basic GIS functions, such as viewing, querying, and doing statistics and making graph. The system has been tested and proved to work effectively enabling the company staff to cost-effectively exploit its drainage Geodatabase through the internet.