776 resultados para geographical information systems (GIS)


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The aim of this work is to understand the morphological expression of ground occupation by the higher income population, by focusing on population distribution in accordance with income layers and demographical density, as well as topological accessibility (HILLIER and HANSON, 1984) resulting from the urban grid structure. It endeavors to identify a functional organizing principle regarding the intra-urban space of Natal capital city of the state of Rio Grande do Norte, the research focus. In order to achieve this, census data as well as syntactic data were utilized for mapping and spatial analysis of income patterns, topological accessibility and demographical density using Geographical Information System GIS. The organizing principle was named as the Form of Privilege, a pattern that concentrates or tends to concentrate wealth, topological accessibility and low demographical density. Attempting to assess its extent, beyond Natal, this principle was applied to other Brazilian northeastern capitals such as: Fortaleza, CE; Teresina, PI; Aracaju, SE; Recife, PE; and João Pessoa, PB. Findings point out that although the urban structures of these cities are not immune to the Form of Privilege, Natal is emblematic of this phenomenon, a fact that demonstrates the perverse character of its spatial process, which historically creates privileged areas within the city, by means of the appropriation of accessibility as well as of the many urban benesses that are related to it by higher income groups at the expense of the major part of the population, which though being the people mostly in need of the benefits originating from the urban form are excluded from them

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La presente monografía, tiene como objetivo analizar y describir las plantas existentes tanto autóctonas como introducidas en las parroquias de: Baños, Ricaurte, San Joaquín y Tarqui, enfocándonos en las más representativas de cada una de ellas. Al mismo tiempo analizar su ubicación, sus características y sus usos en relación a sus habitantes. Esta investigación de carácter tanto bibliográfica como de estudio de campo, se ha realizado utilizando textos y el sistema de información geográfico para generar información de carácter cartográfico, con el propósito de obtener la investigación más actualizada posible. Conociendo la situación actual que vive el planeta en relación con el medio ambiente y la destrucción progresiva del mismo, es importante conocer cuáles son las plantas que aún sobreviven en nuestro medio, su conservación y de qué manera éstas nos ayudan para la preservación de nuestro medio natural.

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Post-print version. Pictures and tables separated from main text and presented at the end.

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Current procedures for flood risk estimation assume flood distributions are stationary over time, meaning annual maximum flood (AMF) series are not affected by climatic variation, land use/land cover (LULC) change, or management practices. Thus, changes in LULC and climate are generally not accounted for in policy and design related to flood risk/control, and historical flood events are deemed representative of future flood risk. These assumptions need to be re-evaluated, however, as climate change and anthropogenic activities have been observed to have large impacts on flood risk in many areas. In particular, understanding the effects of LULC change is essential to the study and understanding of global environmental change and the consequent hydrologic responses. The research presented herein provides possible causation for observed nonstationarity in AMF series with respect to changes in LULC, as well as a means to assess the degree to which future LULC change will impact flood risk. Four watersheds in the Midwest, Northeastern, and Central United States were studied to determine flood risk associated with historical and future projected LULC change. Historical single framed aerial images dating back to the mid-1950s were used along with Geographic Information Systems (GIS) and remote sensing models (SPRING and ERDAS) to create historical land use maps. The Forecasting Scenarios of Future Land Use Change (FORE-SCE) model was applied to generate future LULC maps annually from 2006 to 2100 for the conterminous U.S. based on the four IPCC-SRES future emission scenario conditions. These land use maps were input into previously calibrated Soil and Water Assessment Tool (SWAT) models for two case study watersheds. In order to isolate effects of LULC change, the only variable parameter was the Runoff Curve Number associated with the land use layer. All simulations were run with daily climate data from 1978-1999, consistent with the 'base' model which employed the 1992 NLCD to represent 'current' conditions. Output daily maximum flows were converted to instantaneous AMF series and were subsequently modeled using a Log-Pearson Type 3 (LP3) distribution to evaluate flood risk. Analysis of the progression of LULC change over the historic period and associated SWAT outputs revealed that AMF magnitudes tend to increase over time in response to increasing degrees of urbanization. This is consistent with positive trends in the AMF series identified in previous studies, although there are difficulties identifying correlations between LULC change and identified change points due to large time gaps in the generated historical LULC maps, mainly caused by unavailability of sufficient quality historic aerial imagery. Similarly, increases in the mean and median AMF magnitude were observed in response to future LULC change projections, with the tails of the distributions remaining reasonably constant. FORE-SCE scenario A2 was found to have the most dramatic impact on AMF series, consistent with more extreme projections of population growth, demands for growing energy sources, agricultural land, and urban expansion, while AMF outputs based on scenario B2 showed little changes for the future as the focus is on environmental conservation and regional solutions to environmental issues.

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The increasing trend of disaster victims globally is posing a complex challenge for disaster management authorities. Moreover, to accomplish successful transition between preparedness and response, it is important to consider the different features inherent to each type of disaster. Floods are portrayed as one of the most frequent and harmful disasters, hence introducing the necessity to develop a tool for disaster preparedness to perform efficient and effective flood management. The purpose of the article is to introduce a method to simultaneously define the proper location of shelters and distribution centers, along with the allocation of prepositioned goods and distribution decisions required to satisfy flood victims. The tool combines the use of a raster geographical information system (GIS) and an optimization model. The GIS determines the flood hazard of the city areas aiming to assess the flood situation and to discard floodable facilities. Then, the multi-commodity multimodal optimization model is solved to obtain the Pareto frontier of two criteria: distance and cost. The methodology was applied to a case study in the flood of Villahermosa, Mexico, in 2007, and the results were compared to an optimized scenario of the guidelines followed by Mexican authorities, concluding that the value of the performance measures was improved using the developed method. Furthermore, the results exhibited the possibility to provide adequate care for people affected with less facilities than the current approach and the advantages of considering more than one distribution center for relief prepositioning.

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Migratory bird species breeding in the Palearctic and overwintering in sub-Saharan Africa face multiple conservation challenges. As a result, many of these species have declined in recent decades, some dramatically. We therefore used the best available database for the distribution of 68 passerine migrants in sub-Saharan Africa to determine priority regions for their conservation. After modeling each species’ distribution using BIOMOD software, we entered the resulting species distributions at a 1° × 1° grid resolution into MARXAN software. We then used several different selection procedures that varied the boundary length modifier, species penalty factor, and the inclusion of grid cells with high human footprint and with protected areas. While results differed between selection procedures, four main regions were regularly selected: (1) one centered on southern Mali; (2) one including Eritrea, central Sudan, and northern Ethiopia; (3) one encompassing southwestern Kenya and much of Tanzania and Uganda; and (4) one including much of Zimbabwe and southwestern Zambia. We recommend that these four regions become priority regions for research and conservation efforts for the bird species considered in this study.

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La danta centroamericana (Tapirus bairdii) es el mamífero terrestre de mayor tamaño en el Neotrópico. Es un importante dispersor de semillas que contribuye al enriquecimiento de especies en los bosques donde habita. Varios estudios ecológicos han permitido conocer esta especie discreta; sin embargo, su distribución y el tamaño de sus poblaciones permanece sensiblemente desconocido fuera de las áreas silvestres protegidas. El propósito de esta investigación consistió en proponer una metodología de análisis geo-espacial sencilla que permitiera realizar una evaluación rápida del hábitat potencial para la danta centroamericana. Se seleccionaron siete variables de la ecología de la danta centroamericana, las cuales fueron evaluadas en el Corredor Biológico San Juan-La Selva, mediante un sistema de información geográfica (SIG). Estimamos la población de dantas con un rango de 69 a 208 individuos. Esto es una manera barata de determinar la viabilidad del hábitat de la danta cuando existe información confiable sobre los procesos dinámicos de los ecosistemas presentes en el área del estudio.Palabras clave: Tapiridae, danta centroamericana, Tapirus bairdii, evaluación de hábitat, analisis geo-espacial, Corredor Biológico San Juan-La Selva, Costa RicaAbstract: Baird’s Tapir (Tapirus bairdii) is the largest terrestrial mammal in the Neotropics. It is an important seed disperser that contributes to the enrichment of species in the forests where it lives. Several ecological studies on this species have generated knowledge about this discreet species; nevertheless, its distribution and the size of its populations outside protected wildlife areas sensibly remain unknown. The purpose of this investigation consisted in proposing a simple methodology of geo-space analysis that allowed realizing a fast evaluation of the potential habitat for Baird’s Tapir. Seven variables of the ecology of Baird’s Tapir were selected, which were evaluated in the San Juan-La Selva Biological Corridor, using a geographical information system (GIS) program. We estimated the tapir population to range from 69 to 208 individuals. This is an inexpensive way to assess Tapir’s habitat viability when there is a strong knowledge about the dynamic processes from the ecosystems present in the study area.Key Words: Tapiridae, Baird’s Tapir, Tapirus bairdii, habitat viability assessment, geo-spatial analysis, San Juan-La Selva Biological Corridor, Costa Rica

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Este trabajo presenta un estudio retrospectivo de los orígenes y evolución de la aplicación de Sistemas de  Información Geográfca  (SIG) y Teledetección  (TD) en nuestro país. Se  inicia por el  rol desempeñado del Profesor Merrill Lyew dentro de  la Escuela de Ciencias Geográfcas de la Universidad Nacional, pasando luego por una breve descripción del proceso de implementación de SIG y TD en los centros de enseñanza superior estatales.En esta breve descripción se analiza cómo diferentes unidades académicas han ido incorporando la tecnología SIG y TD en sus planes de estudio.Posteriormente, se presenta una aproximación de la situación actual SIG y TD en las instituciones públicas y privadas y cómo ellas han venido incorporando estas tecnologías en su quehacer diario. Se hace alusión a diferentes eventos que se han llevado en Costa Rica con el objetivo de compartir experiencias en las más diversas aplicaciones.De la misma manera se citan algunas de las principales empresas privadas que se dedican a la venta de insumos, aplicaciones, capacitaciones y software en el campo SIG y TD. En el camino óptimo se visualizan dos opciones por seguir:  la consolidación ofcial de un organismo, comisión o secretaría que tenga bajo su responsabilidad la organización de la Infraestructura Nacional de Datos Geoespaciales. La segunda versa sobre el esfuerzo realizado por las Escuelas de Geografía de la Universidad de Costa Rica y Universidad Nacional para ofrecer a partir del 2008 el Programa de Maestría Profesional en Sistemas de Información Geográfca y Teledetección. Palabras claves: Sistemas de Información Geográfca (SIG), Teledetección, Evolución, Historia, Costa Rica.Abstract This work is a retrospective study of the origins and evolution of the applications of Geographic Information Systems (GIS) and Remote Sensing in our country. It begins with the work of Prof. Merryl Lyew of the School of Geographic Sciences at Universidad Nacional and continues with a brief description of the GIS and Remote Sensing implementation process at state centers of higher education.It  also  analyzes  how  different  academic  departments  have  incorporated GIS  and Remote Sensing technology in their courses of study.Subsequently, this work presents an approximation of the actual situation regarding GIS and remote sensing  in public and private  institutions and how  these  technologies have become incorporated in their daily work. It also refers to the different events that have been carried on in Costa Rica with the objective of sharing experiences in the most diverse applications. In the same way, this work cites some of the principal private businesses dedicated to the sale of supplies, applications, training and software in the feld of GIS and remote sensing. Two options are seen as the best way to pursue the offcial consolidation of an agency, commission  or  administrative  department  to  have  under  its  responsibility  organization  of  the National Infrastructure of Geospatial Data. The second deals with the successful effort by the School of Geographic Sciences at Universidad Nacional of Costa Rica as of 2008 to offer the Professional Master’s program in Geographic Information Systems and Remote Sensing.KEyWordS: Geographic Information Systems (GIS), Remote Sensing, Origin, Evolution, Costa Rica, Universidad Nacional

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Este artículo se deriva de una investigación más amplia sobre la contaminación de la cuenca del río Ciruelas, aplicando métodos y técnicas de investigación geográfica. A partir de la definición de las características físico-naturales, del uso de la tierra, su dinámica y de los análisis físicos, químicos y bacteriológicos de las aguas, se procede a la precisión de áreas críticas. Los resultados obtenidos se incluyen en una cartografía temática de rigurosa elaboración con base en la aplicación de Sistemas de Información Geográfica (SIGs). Finalmente, se entregan una serie de conclusiones y recomendaciones orientadas a mejorar la calidad ambiental de la cuenca del río Ciruelas. ABSTRACT This article derives from a broader research developed by the authors about the Ciruelas river watershed contamination. Applying geographical research methods and techniques. Critical areas are identified after the definition of physical and natural characteristics, land use determination, and the physical, chemical and bacteriological analysis of water and its dynamics. Outcomes are included in a theme cartography of rigorous elaboration based on Geographical Information Systems application. Finally, a series of conclusions and recommendations are given focusing on the improvement of the environmental quality of the Ciruelas river watershed.

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Desde hace algunos años los sistemas de Posicionamiento Global (SPG) se están imponiendo como una herramienta interesante e, incluso, imprescindible para el posicionamiento y la navegación – marítima, aérea y terrestre – y con importantes aplicaciones en los campos de la cartografía, la teledetección, los sistemas de información Geográfica, la Topografía, etc. En este artículo realizamos una introducción a los SPG, haciendo un repaso de los componentes, de la forma de calcular la distancia, de la precisión y de la metodología de trabajo con ellos.ABSTRACT For some years now, Global Positioning Systems (GPS) have become interesting and indispensable tools for determining geographical positioning for air, land and marine navigation, as well as having important applications in the area on Cartography, Remote Sensing, Geographical Information Systems, Surveying, etc. In this article, we present an introduction to GPS and summarize the necessary components, ways to calculate distance and precision, and methodologies for working with them.

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Introduction: Brazil, is one of the main agricultural producers in the world ranking 1st in the production of sugarcane, coffee and oranges. It is also 2nd as world producer of soybeans and a leader in the harvested yields of many other crops. The annual consumption of mineral fertilizers exceeds 20 million mt, 30% of which corresponds to potash fertilizers (ANDA, 2006). From this statistic it may be supposed that fertilizer application in Brazil is rather high, compared with many other countries. However, even if it is assumed that only one fourth of this enormous 8.5 million km2 territory is used for agriculture, average levels of fertilizer application per hectare of arable land are not high enough for sustainable production. One of the major constraints is the relatively low natural fertility status of the soils which contain excessive Fe and Al oxides. Agriculture is also often practised on sandy soils so that the heavy rainfall causes large losses of nutrients through leaching. In general, nutrient removal by crops such as sugarcane and tropical fruits is much more than the average nutrient application via fertilization, especially in regions with a long history of agricultural production. In the recently developed areas, especially in the Cerrado (Brazilian savanna) where agriculture has expanded since 1980, soils are even poorer than in the "old" agricultural regions, and high costs of mineral fertilizers have become a significant input factor in determining soybean, maize and cotton planting. The consumption of mineral fertilizers throughout Brazil is very uneven. According to the 1995/96 Agricultural Census, only in eight of the total of 26 Brazilian states, were 50 per cent or more of the farms treated "systematically" with mineral fertilizers; in many states it was less than 25 per cent, and in five states even less than 12 per cent (Brazilian Institute for Geography and Statistics; Censo Agropecuario1995/96, Instituto Brazileiro de Geografia e Estadistica; IBGE, www.ibge.gov.br). The geographical application distribution pattern of mineral fertilizers may be considered as an important field of research. Understanding geographical disparities in fertilization level requires a complex approach. This includes evaluation of the availability of nutrients in the soil (and related soil properties e.g. CEC and texture), the input of nutrients with fertilizer application, and the removal of nutrients by harvested yields. When all these data are compiled, it is possible to evaluate the balance of particular nutrients for certain areas, and make conclusions as to where agricultural practices should be optimized. This kind of research is somewhat complicated, because it relies on completely different sources of data, usually from incomparable data sources, e.g. soil characteristics attributed to soil type areas, in contrast to yields by administrative regions, or farms. A priority tool in this case is the Geographical Information System (GIS), which enables attribution of data from different fields to the same territorial units, and makes possible integration of these data in an "inputoutput" model, where "input" is the natural availability of a nutrient in the soil plus fertilization, and "output" export of the same nutrient with the removed harvested yield.

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Historical GIS has the potential to re-invigorate our use of statistics from historical censuses and related sources. In particular, areal interpolation can be used to create long-run time-series of spatially detailed data that will enable us to enhance significantly our understanding of geographical change over periods of a century or more. The difficulty with areal interpolation, however, is that the data that it generates are estimates which will inevitably contain some error. This paper describes a technique that allows the automated identification of possible errors at the level of the individual data values.

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We show a simulation model for capacity analysis in mobile systems using a geographic information system (GIS) based tool, used for coverage calculations and frequency assignment, and MATLAB. The model was developed initially for “narrowband” CDMA and TDMA, but was modified for WCDMA. We show also some results for a specific case in “narrowband” CDMA

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The computing tools and technologies with urban information systems are designed to enhance planners’ capability to deal with complex urban environments and to plan for prosperous and liveable communities. This paper examines the role of Online Urban Information Systems or in another words Internet based Geographic Information Systems as spatial decision support systems to aid local planning process. This paper introduces a prototype Internet GIS model that aims to integrate a public oriented interactive decision support system for urban planning process. This model, referred as a ‘Community based Internet GIS’, incorporates advanced information technologies and community involvement in decision making processes on the web environment. This innovative model has been recently applied to a pilot case in Tokyo and this paper concludes with the preliminary results of this project.