Free GIS Research Articles

Relief visualization techniques using free and open source GIS tools

Abstract The aim of the article is to present different relief visualization techniques created using only free and open source GIS tools, such as QGIS and RVT. The criteria for selection of these techniques are that they should be, on the one hand, simple and fast for implementation and on the other suitable for multiple visualization purposes. Here we present several techniques which combine hillshade with other relief data layers derived from DEM and an assessment of advantages and disadvantages of their visualization.

Aplicación del modelo de regresión múltiple para la interpolación de las temperaturas y precipitaciones de la península ibérica y las Islas Baleares

Se han elaborado mapas de precipitación mensual y temperatura media mensual para la península ibérica y Baleares mediante la interpolación de los valores de 3736 estaciones pluviométricas y 1626 estaciones termométricas, con software estadístico y de sistemas de información geográfica libres. El método utilizado fue la regresión múltiple con interpolación de residuos. Distintas variables no utilizadas en modelos anteriores mejoraron el ajuste de las regresiones. Entre ellas la altitud y pendiente medias en el caso de la precipitación y la radiación real en la temperatura. La validación de los modelos con el 30 % de los datos presenta errores similares a los obtenidos en trabajos previos. La comparación de los datos del modelo climático con los de los 60 Observatorios Meteorológicos Principales españoles para los tres últimos periodos climáticos referenciales (1961-1990, 1971-2000 y 1981-2010), muestra que el modelo, en líneas generales, sobrestima las precipitaciones y subestima las temperaturas actuales debido a los cambios climáticos recientes.

Towards sustainable urban sanitation: a capacity-building approach to wastewater mapping for small towns in India

AbstractDecentralized technologies and city-based governance are being actively promoted for urban sanitation in low-income countries. At the same time, municipal agencies in developing countries have little technical or financial capacity for sanitation planning. This paper develops an approach to sanitation planning that leverages citizen engagement and fosters local capacities. It presents an empirical study from two small towns in India, where collaborations among the research team, local academics and students, and the municipal government, produced planning-oriented sanitary maps of each town. The maps were built upon a social and spatial understanding of the diverse sanitation practices that already exist, coupled with Google Earth and free GIS software. The ‘waste watersheds’ and ‘sanitation zones’ identified through the mapping process provide a basis on which sanitation interventions can be assessed and weighed, so that sustainable solutions can be prioritized. The paper identifies three features for system interventions: first, making local municipal government the locus of sanitation interventions; second, engaging community-based organizations and academic institutions to develop local capacity; and finally, recognizing the fragmented nature of cities by developing a socio-spatial approach to sanitation zoning.

Análise Multitemporal de Uso e Ocupação do Solo com Enfoque na Silvicultura no Município de Cândido Sales, Bahia, nos Anos de 2005 e 2015

A review of the soil use and occupation in different years is a way to know the evolution of the impacts of human activities. The present study aims to analyze the soil use and occupation with a focus on forestry in the municipality of Cândido Sales, Bahia, in different periods. The satellite images were obtained from the image catalog the National Institute for Space Research (INPE). Images related to September 2005 and 2015 were selected from the satellite Landsat - 5. For the categorization of the soil use and occupation, we used the classification of maximum verisimilitude and supervised classification the digital images. The processing and analysis were performed using the free software Quantum GIS version 2.6.1. Four classes of the soil use and occupation were defined: Forest planting, Dense vegetation, Altered vegetation and Undergrowth/Exposed soil. After defining the use of classes, the classification automatic monitored image was carried out in order to determine the soil use and occupation. During the studied period, the soil use and occupation in the city has changed, especially in the reduction of forest planting and undergrowth/exposed soil, as well as increasing the dense vegetation and altered vegetation.

FloodRisk: a collaborative, free and open-source software for flood risk analysis

ABSTRACTThe European ‘Floods Directive’ 2007/60/EC focuses on the development of flood risk maps and management plans on the basis of the most appropriate and advanced tools. This pushed a paradigm shift for moving to sustainable development through processes of stakeholder engagement to improve the efficiency and transparency of decision processes. In this context, this research project developed a free and open-source GIS software, called FloodRisk, to operatively support stakeholders in their compliance with risk map delineation and the management of current and future flood risk based on their needs for multi-purpose applications. In this paper, a high-resolution impact assessment framework based on 2D inundation modelling with different return periods was used, as input, within the FloodRisk model to reconstruct the socio-economic damages based on a case study showing how structural and non-structural measures can significantly decrease the cost of floods for households. The sensitivity of the FloodRisk model was also examined and it was found to be highly dependent on the selection of damage functions and the economic values of the exposed assets.

Archaeological spatial analysis and GIS in a small fortification: Ephemeral occupations along the border during the ‘Conquest of Desert’ process in Argentinean Pampas (19th Century)

In the following paper we formulate an interpretation about how the space was managed inside a classic ‘Fortín’, a sort of small fort, which was located in the Argentinean Pampas during the 1860–1870's period. We review the main features of these sites, like the nature of its structures and buildings or the quick abandonment of military positions due to the advancing process in the frontier. As a case study, Fortín Otamendi site is a large area (>2600sq.m) divided in several sectors where we had detected and confirmed different scatterings of heterogeneous archaeological remains (e.g. fauna, lithics, metals, glasses…), both in the site and its proximities.Analytical steps in this research on spatial distributions have been developed from free GIS platform (QGIS) and geostatistical methods. Our aims are to establish an efficient fieldwork, to quantify and characterize spatial distributions, and –according the results obtained–, to solve the problem related with building potential locations, for which we have estimated the probability of a structure location in terms of subareas with significantly low-density distributions of remains.

Free satellite imagery and digital elevation model analyses enabling natural resource management in the developing world: Case studies from Eastern Indonesia

Decentralization of governance and natural resource management is an ongoing process in many parts of Africa and Asia. Natural resource management requires spatial land resource data for planning. However, currently the financial and human capacity for natural resource mapping, monitoring and modelling remains low in local governments. In this context, this paper explores how new opportunities provided by the increasing availability of free satellite imagery, digital elevation data and open source spatial analysis software, can be applied by local government and NGOs to conduct sophisticated natural resource mapping and modelling in ways that meet their needs and incorporates local knowledge. Reported are cases of a local government using free geospatial data and GIS software to improve evidence‐based natural resource management in the developing world with a focus on raster data applications for satellite image analysis and terrain modelling. It is argued that, through removing barriers to uptake, such applications provide a means of decentralizing landscape analysis skills to improve local natural resource management. This hypothesis is supported through examples of a local government applying these tools in eastern Indonesia, and within this context barriers to wider adoption are explored.

BUILDING A COMPLETE FREE AND OPEN SOURCE GIS INFRASTRUCTURE FOR HYDROLOGICAL COMPUTING AND DATA PUBLICATION USING GIS.LAB AND GISQUICK PLATFORMS

Abstract. Building a complete free and open source GIS computing and data publication platform can be a relatively easy task. This paper describes an automated deployment of such platform using two open source software projects – GIS.lab and Gisquick. GIS.lab (http: //web.gislab.io) is a project for rapid deployment of a complete, centrally managed and horizontally scalable GIS infrastructure in the local area network, data center or cloud. It provides a comprehensive set of free geospatial software seamlessly integrated into one, easy-to-use system. A platform for GIS computing (in our case demonstrated on hydrological data processing) requires core components as a geoprocessing server, map server, and a computation engine as eg. GRASS GIS, SAGA, or other similar GIS software. All these components can be rapidly, and automatically deployed by GIS.lab platform. In our demonstrated solution PyWPS is used for serving WPS processes built on the top of GRASS GIS computation platform. GIS.lab can be easily extended by other components running in Docker containers. This approach is shown on Gisquick seamless integration. Gisquick (http://gisquick.org) is an open source platform for publishing geospatial data in the sense of rapid sharing of QGIS projects on the web. The platform consists of QGIS plugin, Django-based server application, QGIS server, and web/mobile clients. In this paper is shown how to easily deploy complete open source GIS infrastructure allowing all required operations as data preparation on desktop, data sharing, and geospatial computation as the service. It also includes data publication in the sense of OGC Web Services and importantly also as interactive web mapping applications.

Feasibility assessment of an Organic Rankine Cycle (ORC) cogeneration plant (CHP/CCHP) fueled by biomass for a district network in mainland Spain

A previously developed procedure to evaluate a biomass plant feasibility has been improved, now considering availability and cost of the biomass resources around the plant's location. The plant is an organic Rankine cycle cogeneration facility located in mainland Spain. All the villages over 15.000 inhabitants have been considered as potential locations. Partial load operation is considered as well as cogeneration (CHP) and trigeneration (CCHP) schemes. Biomass calculations were performed using BIORAISE (a free GIS tool) showing that, in all the locations, the available biomass within a 30-km radius is larger than the demand, with an average cost of 10 €/MWh. No subsidies have been considered. In CHP operation, all the locations lead to “high efficiency cogeneration” plants, with the best profitability in medium-severe to severe-winter climate zones. In CCHP mode, only locations in medium-to severe-winter climate zones reach “high efficiency”. This mode is worthwhile in climate zones with mild winters and medium to hot summers. The optimum plant size is found to be smaller in CCHP compared to CHP in all the locations and the biggest plants are situated in climate zones with severe winters. Avoided CO2 emissions reach higher values in CHP mode compared to CCHP.

Cost-benefit Analysis with GIS: An Open Source Module for the Forest Bioenergy Sector

Abstract This paper introduces a novel methodology for the optimal use of forest biomass for energy purposes, by means of GIS procedures. The method allows the identification of the most suitable area for a power plant, starting from the energy demand and the local availability of wood resources. After the site identification, the procedure conducts a cost-benefit analysis, including financial and environmental flows. The described methodology has been automatized in GRASS GIS, which is a free and open source GIS software, and now constitutes a downloadable add-on. In this contribution, we tested such procedure in a case study in Italy, the alpine valleys of Gesso and Vermenagna in Piedmont region (North-West of Italy).

Methodology for mapping the average transaction prices of residential premises using GIS

Abstract Geographic information systems (GIS) and their tools support the process of real estate trading. Of key importance is the ability to visualise information about real estate in the form of maps of average real estate transaction prices. The following study presents a methodology for mapping average real estate transaction prices using GIS. The map development process comprised three main stages. In the first stage, the input data was processed and statistically analysed. Official data came from the Register of Real Estate Prices and Values, and open data from the National Register of Boundaries. The second stage involved the visualization of the data in the form of maps of average apartment prices using the cartographic methods of choropleth maps and diagrams. The commercial tool ArcMap 10.3 and the free Quantum GIS software were used in the design of the maps of average real estate transaction prices, to check the options for using these types of programs. As a result, eight maps were designed presenting the average transaction prices for residential properties in the Warsaw district of Ursynów in 2015. The final stage was the analysis of the designed maps. The influence of the selection of the reference units on the visualization content, and the impact of combining cartographic presentation methods on the complexity of the presentation of real estate information, were also analysed.

An open source GIS‐based Planning Support System: Application to the land use plan of La Troncal, Ecuador

AbstractPlanning Support Systems (PSS) comprise a wide variety of geo‐technological tools related to GIS and spatial modeling aimed at addressing land planning processes. This article describes the OpenRules system, a PSS based on a previous system called RULES. Among OpenRules new features are its architecture, based exclusively on free and open source software, and its applicability to all land use types, including rural and urban uses. In addition, OpenRules incorporates an unlimited number of land evaluation factors and a new objective in land use spatial allocation. OpenRules has been programmed in Java and implemented as a module of the free GIS software gvSIG, with full integration between the GIS and the decision support tools. Decision support tools include multicriteria evaluation, multiobjective linear programming and heuristic techniques, which support three basic stages of land use planning processes, namely land suitability evaluation, land use area optimization and land use spatial allocation. The application of OpenRules to the region of La Troncal, Ecuador, demonstrates its capability to generate alternative and coherent solutions through a scientific and justified procedure at low cost in terms of time and resources.

Empowering citizen science through free and open source GIS

This article presents an overview of the GIS components of the COBWEB software framework, designed in order to support a collaborative citizen science environment. It describes the overall architecture of the system, focusing in new developments of existing Free and Open Source GIS software.

OPEN SOURCE APPROACH TO URBAN GROWTH SIMULATION

Spatial patterns of land use change due to urbanization and its impact on the landscape are the subject of ongoing research. Urban growth scenario simulation is a powerful tool for exploring these impacts and empowering planners to make informed decisions. We present FUTURES (FUTure Urban – Regional Environment Simulation) – a patch-based, stochastic, multi-level land change modeling framework as a case showing how what was once a closed and inaccessible model benefited from integration with open source GIS.We will describe our motivation for releasing this project as open source and the advantages of integrating it with GRASS GIS, a free, libre and open source GIS and research platform for the geospatial domain. GRASS GIS provides efficient libraries for FUTURES model development as well as standard GIS tools and graphical user interface for model users. Releasing FUTURES as a GRASS GIS add-on simplifies the distribution of FUTURES across all main operating systems and ensures the maintainability of our project in the future. We will describe FUTURES integration into GRASS GIS and demonstrate its usage on a case study in Asheville, North Carolina. The developed dataset and tutorial for this case study enable researchers to experiment with the model, explore its potential or even modify the model for their applications.

OPEN SOURCE APPROACH TO URBAN GROWTH SIMULATION

Abstract. Spatial patterns of land use change due to urbanization and its impact on the landscape are the subject of ongoing research. Urban growth scenario simulation is a powerful tool for exploring these impacts and empowering planners to make informed decisions. We present FUTURES (FUTure Urban – Regional Environment Simulation) – a patch-based, stochastic, multi-level land change modeling framework as a case showing how what was once a closed and inaccessible model benefited from integration with open source GIS.We will describe our motivation for releasing this project as open source and the advantages of integrating it with GRASS GIS, a free, libre and open source GIS and research platform for the geospatial domain. GRASS GIS provides efficient libraries for FUTURES model development as well as standard GIS tools and graphical user interface for model users. Releasing FUTURES as a GRASS GIS add-on simplifies the distribution of FUTURES across all main operating systems and ensures the maintainability of our project in the future. We will describe FUTURES integration into GRASS GIS and demonstrate its usage on a case study in Asheville, North Carolina. The developed dataset and tutorial for this case study enable researchers to experiment with the model, explore its potential or even modify the model for their applications.

VALORAÇÃO MONETÁRIA DAS ÁRVORES DA SANTA CASA DE MISERICÓRDIA DE PIRACICABA/SP

This research aimed to study the tree composition and the tree monetary appraisal at the Holy House of Mercy of Piracicaba (SP), through biometrics informations and plant assessment of root, root crown, trunk and crown, in a relational database. We did the trees census above 0.05 m of DBH (diameter at breast height) and we found 300 individuals, distributed in 67 species, 59 genus and 30 botanical families, highlighting the species Licania tomentosa (Benth.) Fritsch (10.7%), Caesalpinia pluviosa DC. (9.7%) and Ficus benjamina L. (6.0%), the genus Tabebuia (8.5%) and the families Bignoniaceae (15.3%), Leguminosae-Caesalpinoideae (12.7%) and Chrysobalanaceae (10.7%). The Shannon-Wiener diversity index was 3.56 and the tree appraisal, R$ 1,910,488.20, the individual average value was R$ 6,368.29 and the most valuable tree, Lophanthera lactescens Ducke, R$ 64,723.03. The registration method in relational database proved to be efficient and organized for storage and processing data, as well as the free software Quantum GIS version 2.6, capable to prepare maps about the location of selected trees.

Tools for structural geology analysis in QGIS

QGIS is a free and open source GIS software that is highly customizable through the use of Python scripts. We examine the available tools for structural geology analysis. The common basis of all these tools is constituted by scientific and also visualization modules, like NumPy, SciPy and Matplotlib. A few structural geology Python modules exist, the most notable being Apsg by Ondrej Lexa. It allows manipulating orientation data and presents convenience functions for plotting them in Matplotlib stereonets. Based on these scientific, geologic and visualization modules it is possible to produce scripts or processing plugins for crosssection preparation, attitude interpolations on regular grids and stereonet plotting. Plugins based on Qt GUI are just a few, devoted to the analysis of the relations between geological plane traces and topographic surfaces (qgSurf plugin), to the preparation of cross-sections with projection of geological attitudes and intersection of geological traces or polygons (qProf plugin), management of hydrological data (Midvatten plugin) or digitalization of fractures and other lineaments from referenced digital photos (digiFract plugin).

Analysis of the Variation of the Areas Under Urbanization Pressure Using Entropy Index

Rural development is closely related to the transformation of land space in the immediate vicinity. The fast growth of Large Urban Zones (LUZ) entails rapid changes in land use not only within the city but also outside its territory, even covering whole regions. The impact of LUZ on social and economic communities living in areas close to the urban zones is noticed by many authors and it's especially manifested in forming and thus in land use. Based on these considerations, on the basis of free access spatial data and GIS technology, the authors tried to identify some relationships in the transformation of the structure of spatial capabilities in suburban areas. The study was based on Corine Land Cover (CLC) - surface data obtained by the visual interpretation of satellite images made at the request of the European Environment Agency (EEA), in order to monitor changes in coverage and land use in Europe. Collected in the previous campaign, and now updated every five years the data provide interesting and valuable source of information for analysing and modelling of spatial processes.Based on the obtained data set, the authors using the entropy index, then an indicator of multifunctionality decided to capture the dynamics of change and indicate possible trends of development in the coming years. Definition of entropy follows directly from the Second law of Thermodynamics, and frequently researchers used this value to study the changes of states of various phenomena, including the dynamic development of the area under urbanization pressure. Based on the results obtained erected the argument that the high value of entropy, which is a measure of disorder, is associated with a greater diversity of the area, thus a confirmation of the high dynamics of changes in land use. The authors decided to analyze these issues based on comprehensive and standardized data sets, which is CLC.

Design Method of Housing with Direct Solar Heat Gain by Using GIS Data in Cold Regions

Direct Solar Heat Gain (hereafter DSHG)is defined as the method to decrease heating load by using solar radiation from large south faced windows. Researches for DSHG have been conducted for many years. Although, there is a few research that analyze surroundings obstacles such as buildings, woods etc. It indicates that calculated cooling loads are bigger than an actual value and heating loads are smaller than actual value. Then, Architects and engineer should consider the risks on those research results especially in winter season. Recently, there are some researches for DSHG with woods and city form around a building. However, there are various cases in actual situations.In this research, we developed a method to analyze the effects of DSHG on heating load for detached housing in actual situation by using GIS data. Recently, the services of GIS data have been developing. Google provides GIS data with Google map and Google earth. Japanese government and Japanese prefectural government also provide free (open) GIS data. The data include elevation of a site, shape of buildings, address, number of stories, name, structure, total floor area, etc. Users can use the data with confidentiality agreement. The outline of the surrounding environment (form) is able to be made by using such GIS data. The climate data that is combined with the surrounding environment is able to be used for the analysis of DSHG. In this paper, we report 1st; criteria to judge whether DSHG should be used or not by using GIS data, 2nd; the effect of DSHG under the situation where solar radiation is decreased by surrounding obstacles around building, 3rd; the chart which express the relationship between DSHG effect and interior design.

APLICACIÓN DEL SISTEMA DE INFORMACIÓN GEOGRÁFICO QUANTUM GIS EN LA REGIONALIZACIÓN ECOLÓGICA DE LA CUENCA CIÉNAGA DE LA VIRGEN (CARTAGENA DE INDIAS – COLOMBIA)

The software of free code Quantum GIS (QGIS) is a friendly tool for its application in diverse activities of territorial planning, in the present work its potential of use in processes of ecological regionalization is demonstrated for the Cuenca Ciénaga de la Virgen en Cartagena de Indias (Colombia) and municipal area involved. In addition to enabling a mechanism of democratization of the Geographic Information Systems, QGIS allowed to generate cartographies and enable the hierarchical classification of the ecosystems identified as Unidades Ecológicas de Gestión (UEG) for the Basin under study. At the ecodistrict scale, 3 UEG are identified and at the 9 UEG ecosection scale; process based on the ecosystem approach.