Seismicity and seismic risk in Spain = Sismicite et risque sismique en Espagne

The spanish seismic norm has a direct application in building construction but it recomends specific studies in the case of important public works such us large dams or bridges. For this reason, and to establish specifical criteria in its field of activity, the Dirección General de Obras Hidráulicas of the spanish Ministerio de Obras Públicas y Urbanismo commissioned us a seismotectonical and seismic risk study applicable to Spain, materialized on a series of maps of inmediate and direct use. In this paper we explain the methodology pursued to obtain these maps. It has required, firstly, investigations with the aim to improve the seismic information corresponding to the historical or preinstrumental period, that allowed more precise cuantifications. Secondly, these data have been processed by probabilistic methods, using de intensity as foundamental parameter. The corresponding maps have been developed. Finally, other maps of seismic accelerations have been compiled. La normative sismorresistent espagnole á une application directe dans 1'edification, mais elle recommend la realitation des etudes especifiques dans le cas des travaux publics importants telles que ponts ou barrages. Pour cette raison et pour etablir des criteres especifiques dans son camp dáctivité, la Direccion General de Obras Hidraulicas du Ministerio de Obras Publicas y Urbanismo espagnol a commande un etude sismotectonique et de risque sismique applicable a l'Espagne, materialise en une serie de cartes de utilization directe et inmediate. Dans cette communication on explique la methodologie a suivre pour la realization de cettes cartes. Celá a fait necessaire, d'abord, des recherches pour amelliorer l'information concernant le periode historique ou preinstrumental, ce qui permet des cuantifications plus precises. En second lieu ces faits ont ête traités avec des methodes probabilistes, employant l'intensité come parametre fondamental. En consequence nous avons developpe des cartes d'intensite et d'acceleration sismique.

Estudio experimental sobre la reacción álcali-sílice en el hormigón producida por áridos de reacción lenta

La finalidad de esta investigación se enmarca dentro de los estudios sobre hormigones de presas llevados a cabo en el Laboratorio Central de Estructuras y Materiales del CEDEX. En España se han diagnosticado 18 obras afectadas tanto por la reacción álcali-sílice de tipo rápido como por la de tipo lento. Dos de de las obras, fabricadas con áridos graníticos, no presentan signos de deterioro pero en laboratorio se han hallado productos expansivos. En las 16 presas españolas restantes, el hormigón de 10 de ellas estaba fabricado con áridos graníticos, de las cuales, 7 están afectadas por la reacción de tipo lento. Sin embargo, en las clasificaciones internacionales de las rocas potencialmente reactivas se establece habitualmente que las rocas graníticas son inocuas o de reactividad muy baja. En los casos puntuales encontrados en la literatura, la reactividad de este tipo de áridos se encuentra frecuentemente asociada al cuarzo microcristalino que contienen y ocasionalmente se asocia esta reactividad también al cuarzo deformado y/o microfisurado. En la tesis doctoral de Víctor Daniel Lanza Fernández, también realizada en el CEDEX, se han tratado los áridos de reacción rápida, dando una descripción detallada de los componentes que intervienen en este tipo de reacción y presentando un ensayo eficaz para su detección en el laboratorio. La investigación desarrollada en la presente tesis doctoral se ha centrado en los áridos de reacción lenta, mucho menos estudiados. A partir del estudio bibliográfico realizado sobre este tipo de reacción se ha detectado ciertas lagunas, basadas principalmente en la falta de un método de detección en el laboratorio para los áridos de reacción lenta. No se ha encontrado un procedimiento en el estudio petrográfico que sea fiable y cuantificable para este tipo de áridos. El ensayo acelerado de barras de mortero, que para los áridos de reacción rápida supone un método rápido y fiable, falla en la detección de los áridos de reacción lenta al aplicar los límites normalizados. Si bien en publicaciones recientes se ha propuesto la posibilidad de ampliar el tiempo de tratamiento hasta los 90 días, la duración del ensayo es más larga de lo deseado. Para resolver estas lagunas, se han tomado áridos de obras reales afectadas por la reacción álcali-sílice (en algún caso también de las canteras de donde se extrajeron los áridos para la ejecución), con lo que la reactividad de estos áridos queda demostrada por su comportamiento en obra. Al objeto de aumentar la muestra de ensayo y utilizar también áridos inocuos, se han tomado muestras de canteras, tanto en uso como abandonadas. Sobre estos áridos se ha realizado una caracterización completa con los ensayos actualmente disponibles para el estudio de su reactividad con los álcalis del cemento: estudio petrográfico, ensayo acelerado de barras de mortero y Gel-Pat modificado. En la investigación se ha desarrollado una metodología de tinción de geles álcali-sílice para la cuantificación de los mismos en el interior de las barras de mortero. Se ha relacionado el volumen de gel generado en la reacción con la expansión producida, tanto para áridos lentos, como rápidos, estableciendo analogías y diferencias en el comportamiento de ambos. La cuantificación de este tipo de compuestos realizada en las barras de mortero, abre la posibilidad de estudiar la capacidad expansiva que presentan en testigos de hormigón de obras afectadas. Este dato podría ser una herramienta importante para el desarrollo de modelos matemáticos que puedan predecir el futuro comportamiento de las estructuras afectadas por la reacción álcali-sílice. La tinción ha sido asimismo utilizada para establecer un método de detección de áridos reactivos basado en el ensayo de Gel-Pat modificado. La metodología de detección propuesta para estos áridos es cuantitativa y proporciona los resultados en 14 días, suponiendo una ventaja importante sobre los métodos actuales, que permiten detectarlos en 90 días (de forma orientativa en 56 días). This research is part of the studies on durability of concrete dams carried out in the Laboratorio Central de Estructuras y Materiales of CEDEX during the last years. At the present time, 18 public works affected by alkali-silica reaction have been diagnosed in Spain. In 12 of them the concrete was mixed with granitic aggregates, 7 of which were damaged by the slow alkali-silica reaction, 3 by the rapid alkali-silica reaction and in the other 2 cases, although there was no visual evidence of the reaction in field, the laboratory tests showed the presence of expansive products inside the concrete. However, in the international classifications of potentially reactive aggregates granitic rocks are pointed out as innocuous or as low reactivity and usually their reactivity is attributed to the presence of microcrystalline quartz and occasionally with the strained and microcracked quartz. The rapid reactive aggregates were deeply studied in a previous research (Víctor Daniel Lanza’s Thesis) also carried out in CEDEX. In this research, a detailed description of the components involved in the rapid alkali-silica reaction was given. Also, a fast method to detect them in the laboratory was developed. The research of the present PhD Thesis is focused in the slow-reactive aggregates, much less studied. The state of the art has shown some gaps in the knowledge about this reaction, mainly the absence of a reliable method to detect slow-reactive aggregates. On one side, there is no systematic and quantitative petrographic test for these aggregates. On the other side, the accelerated mortar bar test has been proved to be effective to detect rapid reactive aggregates but the standard limits fail in the detection of the slowreactive aggregates. In recent investigations it has been proposed extending the test until 90 days, but this period is considered too long. In this research, aggregates taken from affected structures have been used in the test, so their reactivity has been shown in practice. With the aim of increasing the number of samples aggregates from quarries have been also used. A method to stain alkali-silica gels has been applied to mortar bars, thereby quantifying the volume of gel generated inside. This volume has been related to the expansion of the bars, both for rapid for slow reactive aggregates, establishing similarities and differences. The quantification of the gel volume, applied to concrete cores extracted from affected structures, could be an important tool in mathematical models to predict the future behaviour of the structures affected by the alkali-silica reaction. The staining method has been also used to develop a method to detect slow reactive aggregates, based on the optimised Gel-Pat test, obtaining results in 14 days. This represents a major improvement compared to the actual methods (accelerated mortar bar test) which give an indicative value of reactivity at 56 days, and a final result at 90 days.

Sustainable Living. Environmental integration in 15 vernacular Spanish houses

This research was published online by the Spanish Ministry of Public Works in 2012. It collects 20 years of work that contributes to recognizing and enhancing the vernacular architecture in Spain, which has no known author, but has significant values and shows a wide variety of adaptation examples to climatic and environmental conditions. The research analyzes in detail and from different scales 15 houses in different climatic conditions and geographic regions in order to go deeper into the specific characteristics of each one of them from the perspective of sustainability. These houses are located in Tenerife, Salamanca, Huelva, Granada, Toledo, Madrid, Menorca, Alicante, Mallorca, Almería, La Coruña, Cantabria, Huesca and Lugo. The article analyzes the traditional dwelling, the natural environment and conditions that surround it and intends to discover the formal dialogue among them, as well as the origin of the design strategies

Modelo para la integración del trazado de infraestructuras lineales en el paisaje y el medio ambiente basado en SIG

El análisis de las diferentes alternativas en la planificación y diseño de corredores y trazados de carreteras debe basarse en la correcta definición de variables territoriales que sirvan como criterios para la toma de decisión y esto requiere un análisis ambiental preliminar de esas variables de calidad. En España, los estudios de viabilidad de nuevas carreteras y autovías están asociados a una fase del proceso de decisión que se corresponde con el denominado Estudio Informativo, el cual establece condicionantes físicos, ambientales, de uso del suelo y culturales que deben ser considerados en las primeras fases de la definición del trazado de un corredor de carretera. Así, la metodología más frecuente es establecer diferentes niveles de capacidad de acogida del territorio en el área de estudio con el fin de resumir las variables territoriales en mapas temáticos y facilitar el proceso de trazado de las alternativas de corredores de carretera. El paisaje es un factor limitante a tener en cuenta en la planificación y diseño de carreteras y, por tanto, deben buscarse trazados más sostenibles en relación con criterios estéticos y ecológicos del mismo. Pero este factor no es frecuentemente analizado en los Estudios Informativos e incluso, si es considerado, los estudios específicos de la calidad del paisaje (estético y ecológico) y de las formas del terreno no incorporan las recomendaciones de las guías de trazado para evitar o reducir los impactos en el paisaje. Además, los mapas de paisaje que se generan en este tipo de estudios no se corresponden con la escala de desarrollo del Estudio Informativo (1:5.000). Otro déficit común en planificación de corredores y trazados de carreteras es que no se tiene en cuenta la conectividad del paisaje durante el proceso de diseño de la carretera para prevenir la afección a los corredores de fauna existentes en el paisaje. Este déficit puede originar un posterior efecto barrera en los movimientos dispersivos de la fauna y la fragmentación de sus hábitats debido a la ocupación parcial o total de las teselas de hábitats con importancia biológica para la fauna (o hábitats focales) y a la interrupción de los corredores de fauna que concentran esos movimientos dispersivos de la fauna entre teselas. El objetivo principal de esta tesis es mejorar el estudio del paisaje para prevenir su afección durante el proceso de trazado de carreteras, facilitar la conservación de los corredores de fauna (o pasillos verdes) y la localización de medidas preventivas y correctoras en términos de selección y cuantificación de factores de idoneidad a fin de reducir los impactos visuales y ecológicos en el paisaje a escala local. Concretamente, la incorporación de valores cuantitativos y bien justificados en el proceso de decisión permite incrementar la transparencia en el proceso de diseño de corredores y trazados de carreteras. Con este fin, se han planteado cuatro preguntas específicas en esta investigación (1) ¿Cómo se seleccionan y evalúan los factores territoriales limitantes para localizar una nueva carretera por los profesionales españoles de planificación del territorio en relación con el paisaje? (2) ¿Cómo pueden ser definidos los corredores de fauna a partir de factores del paisaje que influyen en los movimientos dispersivos de la fauna? (3) ¿Cómo pueden delimitarse y evaluarse los corredores de fauna incluyendo el comportamiento parcialmente errático en los movimientos dispersivos de la fauna y el efecto barrera de los elementos antrópicos a una escala local? (4) ¿Qué y cómo las recomendaciones de diseño de carreteras relacionadas con el paisaje y las formas del terreno pueden ser incluidas en un modelo de Sistemas de Información Geográfica (SIG) para ayudar a los ingenieros civiles durante el proceso de diseño de un trazado de carreteras bajo el punto de vista de la sostenibilidad?. Esta tesis doctoral propone nuevas metodologías que mejoran el análisis visual y ecológico del paisaje utilizando indicadores y modelos SIG para obtener alternativas de trazado que produzcan un menor impacto en el paisaje. Estas metodologías fueron probadas en un paisaje heterogéneo con una alta tasa de densidad de corzo (Capreolus capreolus L.), uno de los grandes mamíferos más atropellados en la red de carreteras españolas, y donde está planificada la construcción de una nueva autovía que atravesará la mitad del área de distribución del corzo. Inicialmente, se han analizado las variables utilizadas en 22 estudios de proyectos de planificación de corredores de carreteras promovidos por el Ministerio de Fomento entre 2006 y 2008. Estas variables se agruparon según condicionantes físicos, ambientales, de usos del suelo y culturales con el fin de comparar los valores asignados de capacidad de acogida del territorio a cada variable en los diferentes estudios revisados. Posteriormente, y como etapa previa de un análisis de conectividad, se construyó un mapa de resistencia de los movimientos dispersivos del corzo en base a la literatura y al juicio de expertos. Usando esta investigación como base, se le asignó un valor de resistencia a cada factor seleccionado para construir la matriz de resistencia, ponderándolo y combinándolo con el resto de factores usando el proceso analítico jerárquico y los operadores de lógica difusa como métodos de análisis multicriterio. Posteriormente, se diseñó una metodología SIG para delimitar claramente la extensión física de los corredores de fauna de acuerdo a un valor umbral de ancho geométrico mínimo, así como la existencia de múltiples potenciales conexiones entre cada par de teselas de hábitats presentes en el paisaje estudiado. Finalmente, se realizó un procesado de datos Light Detection and Ranging (LiDAR) y un modelo SIG para calcular la calidad del paisaje (estético y ecológico), las formas del terreno que presentan características similares para trazar una carretera y la acumulación de vistas de potenciales conductores y observadores de los alrededores de la nueva vía. Las principales contribuciones de esta investigación al conocimiento científico existente en el campo de la evaluación del impacto ambiental en relación al diseño de corredores y trazados de carreteras son cuatro. Primero, el análisis realizado de 22 Estudios Informativos de planificación de carreteras reveló que los métodos aplicados por los profesionales para la evaluación de la capacidad de acogida del territorio no fue suficientemente estandarizada, ya que había una falta de uniformidad en el uso de fuentes cartográficas y en las metodologías de evaluación de la capacidad de acogida del territorio, especialmente en el análisis de la calidad del paisaje estético y ecológico. Segundo, el análisis realizado en esta tesis destaca la importancia de los métodos multicriterio para estructurar, combinar y validar factores que limitan los movimientos dispersivos de la fauna en el análisis de conectividad. Tercero, los modelos SIG desarrollados Generador de alternativas de corredores o Generator of Alternative Corridors (GAC) y Eliminador de Corredores Estrechos o Narrow Corridor Eraser (NCE) pueden ser aplicados sistemáticamente y sobre una base científica en análisis de conectividad como una mejora de las herramientas existentes para la comprensión el paisaje como una red compuesta por nodos y enlaces interconectados. Así, ejecutando los modelos GAC y NCE de forma iterativa, pueden obtenerse corredores alternativos con similar probabilidad de ser utilizados por la fauna y sin que éstos presenten cuellos de botella. Cuarto, el caso de estudio llevado a cabo de prediseño de corredores y trazado de una nueva autovía ha sido novedoso incluyendo una clasificación semisupervisada de las formas del terreno, filtrando una nube de puntos LiDAR e incluyendo la nueva geometría 3D de la carretera en el Modelo Digital de Superficie (MDS). El uso combinado del procesamiento de datos LiDAR y de índices y clasificaciones geomorfológicas puede ayudar a los responsables encargados en la toma de decisiones a evaluar qué alternativas de trazado causan el menor impacto en el paisaje, proporciona una visión global de los juicios de valor más aplicados y, en conclusión, define qué medidas de integración paisajística correctoras deben aplicarse y dónde. ABSTRACT The assessment of different alternatives in road-corridor planning and layout design must be based on a number of well-defined territorial variables that serve as decision-making criteria, and this requires a high-quality preliminary environmental analysis of those quality variables. In Spain, feasibility studies for new roads and motorways are associated to a phase of the decision procedure which corresponds with the one known as the Informative Study, which establishes the physical, environmental, land-use and cultural constraints to be considered in the early stages of defining road corridor layouts. The most common methodology is to establish different levels of Territorial Carrying Capacity (TCC) in the study area in order to summarize the territorial variables on thematic maps and facilitate the tracing process of road-corridor layout alternatives. Landscape is a constraint factor that must be considered in road planning and design, and the most sustainable layouts should be sought based on aesthetic and ecological criteria. However this factor is not often analyzed in Informative Studies and even if it is, baseline studies on landscape quality (aesthetic and ecological) and landforms do not usually include the recommendations of road tracing guides designed to avoid or reduce impacts on the landscape. The resolution of the landscape maps produced in this type of studies does not comply with the recommended road design scale (1:5,000) in the regulations for the Informative Study procedure. Another common shortcoming in road planning is that landscape ecological connectivity is not considered during road design in order to avoid affecting wildlife corridors in the landscape. In the prior road planning stage, this issue could lead to a major barrier effect for fauna dispersal movements and to the fragmentation of their habitat due to the partial or total occupation of habitat patches of biological importance for the fauna (or focal habitats), and the interruption of wildlife corridors that concentrate fauna dispersal movements between patches. The main goal of this dissertation is to improve the study of the landscape and prevent negative effects during the road tracing process, and facilitate the preservation of wildlife corridors (or green ways) and the location of preventive and corrective measures by selecting and quantifying suitability factors to reduce visual and ecological landscape impacts at a local scale. Specifically the incorporation of quantitative and well-supported values in the decision-making process provides increased transparency in the road corridors and layouts design process. Four specific questions were raised in this research: (1) How are territorial constraints selected and evaluated in terms of landscape by Spanish land-planning practitioners before locating a new road? (2) How can wildlife corridors be defined based on the landscape factors influencing the dispersal movements of fauna? (3) How can wildlife corridors be delimited and assessed to include the partially erratic movements of fauna and the barrier effect of the anthropic elements at a local scale? (4) How recommendations of road design related to landscape and landforms can be included in a Geographic Information System (GIS) model to aid civil engineers during the road layout design process and support sustainable development? This doctoral thesis proposes new methodologies that improve the assessment of the visual and ecological landscape character using indicators and GIS models to obtain road layout alternatives with a lower impact on the landscape. These methodologies were tested on a case study of a heterogeneous landscape with a high density of roe deer (Capreolus capreolus L.) –one of the large mammals most commonly hit by vehicles on the Spanish road network– and where a new motorway is planned to pass through the middle of their distribution area. We explored the variables used in 22 road-corridor planning projects sponsored by the Ministry of Public Works between 2006 and 2008. These variables were grouped into physical, environmental, land-use and cultural constraints for the purpose of comparing the TCC values assigned to each variable in the various studies reviewed. As a prior stage in a connectivity analysis, a map of resistance to roe deer dispersal movements was created based on the literature and experts judgment. Using this research as a base, each factor selected to build the matrix was assigned a resistance value and weighted and combined with the rest of the factors using the analytic hierarchy process (AHP) and fuzzy logic operators as multicriteria assessment (MCA) methods. A GIS methodology was designed to clearly delimit the physical area of wildlife corridors according to a geometric threshold width value, and the multiple potential connections between each pair of habitat patches in the landscape. A Digital Surface Model Light Detection and Ranging (LiDAR) dataset processing and a GIS model was performed to determine landscape quality (aesthetic and ecological) and landforms with similar characteristics for the road layout, and the cumulative viewshed of potential drivers and observers in the area surrounding the new motorway. The main contributions of this research to current scientific knowledge in the field of environmental impact assessment for road corridors and layouts design are four. First, the analysis of 22 Informative Studies on road planning revealed that the methods applied by practitioners for assessing the TCC were not sufficiently standardized due to the lack of uniformity in the cartographic information sources and the TCC valuation methodologies, especially in the analysis of the aesthetic and ecological quality of the landscape. Second, the analysis in this dissertation highlights the importance of multicriteria methods to structure, combine and validate factors that constrain wildlife dispersal movements in the connectivity analysis. Third, the “Generator of Alternative Corridors (GAC)” and “Narrow Corridor Eraser (NCE)” GIS models developed can be applied systematically and on a scientific basis in connectivity analyses to improve existing tools and understand landscape as a network composed of interconnected nodes and links. Thus, alternative corridors with similar probability of use by fauna and without bottlenecks can be obtained by iteratively running GAC and NCE models. Fourth, our case study of new motorway corridors and layouts design innovatively included semi-supervised classification of landforms, filtering of LiDAR point clouds and new 3D road geometry on the Digital Surface Model (DSM). The combined used of LiDAR data processing and geomorphological indices and classifications can help decision-makers assess which road layouts produce lower impacts on the landscape, provide an overall insight into the most commonly applied value judgments, and in conclusion, define which corrective measures should be applied in terms of landscaping, and where.

Educación y obra pública durante el primer peronismo : La construcción de escuelas en la provincia de Buenos Aires

Este artículo se propone analizar el Plan Integral de Edificación Escolar (PIEE) que se aprobó en la provincia de Buenos Aires en 1948. El estudio de los cambios que implicó en relación a los proyectos anteriores, y de los alcances y límites de su aplicación durante las gestiones de Domingo A. Mercante (1946-1952) y Carlos Aloé (1952-1955), permite señalar que la ejecución del plan de edificación que impactó de manera significativa en el número de establecimientos educativos fiscales, fue posible debido a una modificación en la inversión de los recursos y a la mayor intervención de las agencias estatales en la planificación de las edificaciones, relacionada con la mayor injerencia en el área educativa que adquirió el Estado provincial durante este periodo

Las maquetas como material didáctico para la enseñanza y aprendizaje de la lectura e interpretación de planos en la ingeniería

Utilizamos las maquetas como herramientas auxiliares para proyectar y mostrar proyectos de ingeniería, pero también pueden ser un excelente material didáctico para la enseñanza y aprendizaje de la lectura, interpretación y realización de los planos que definen un proyecto o sus diferentes elementos. En este trabajo se refiere la experiencia realizada por los autores con los alumnos de Ingeniería Técnica de Obras Públicas dentro de la unidad de Interpretación de Planos de la asignatura de Sistemas de Representación. La dificultad que los alumnos de la materia tienen para interpretar el lenguaje, códigos y convenciones de la expresión gráfica está entre los motivos por los que se ha utilizado las maquetas como método de representación tridimensional que permite hacer comprensibles y fácilmente interpretadas las características constructivas de los diferentes elementos y las operaciones necesarias para pasar de la representación a la realización de la unidad de obra. En la comunicación se describe la actividad realizada con los alumnos, la selección de las unidades a representar, la elaboración de las maquetas y planos, poniendo especial acento en la concordancia entre la representación gráfica y el modelo tridimensional. Asimismo se han analizado las capacidades didácticas de uno de los trabajos realizados por los alumnos así como la evaluación y conclusiones de la experiencia realizada.

La cartografía de las Memorias Generales de Repoblación de 1878: bosquejos y croquis dasográficos y agronómicos

Las Memorias Generales de Repoblación surgen con las disposiciones que desarrollan la Ley de 11 de julio de 1877 sobre repoblación, fomento y mejora de los montes públicos. Elaboradas por el personal de los distritos forestales, se envían al Ministerio de Fomento entre 1878 y 1884. Además de contener los objetivos y las actuaciones repobladoras propuestas por cada distrito, también reflejan, desde el punto de vista de los ingenieros del ramo, la situación de los montes españoles e incluyen en ocasiones, dentro de esta lógica descriptiva, una cartografía básica de contenido forestal, agronómico y geológico. Ésta es conocida en unos pocos casos a través de los originales publicados a mayor escala; pero en otros no se tenía constancia de su existencia más que por referencias documentales. Unos y otros ejemplos se enmarcan dentro del esfuerzo cartográfico español que caracteriza la segunda mitad del siglo XIX.

La frontera marítima fortificada: de la vigilancia a la señalización (XVI-XIX)

During the 16th century an ambitious political programme for building towers and forts bordering the Spanish Empire’s littoral, to protect it, is materialised. This sighting network over the sea horizon had the essential mission of detecting the presence of vessels that supposed a threat. The network was organised through the strategic arrangement of watchtowers taking profit of the geographical features in the topography so that they could communicate among them with a system of visual signs. The virtual union of the stated settlements defined the fortified maritime borderline. At the same time, this network of sentinels was reinforced (in certain settlements) by the construction of fortifications that acted like centres of data reception and supplied the necessary personnel for detection and transmission. So, this mesh was established by observation points (watchtowers) and information and defense centres (fortifications) to make the news arrive to the decision centres. The present communication aims to demonstrate this military strategy providing the inventory of all defensive architectures that marked this limit between the Segura river mouth until the Huertas cape and that these are spotted from the ‘Flat’ island (later Nueva Tabarca). A riverside geography of approxi-mately 30 km long where 3 fortifications and 7 towers of diverse typologies successively took place. Among the most relevant documents of this research, we could mention the plans of the fortifycations in Guardamar and Santa Pola from the 16th century (drawn in the 18th). For this research, drawings of towers made by the Ministry of Public Works at the end of the 19th century are also important; these documents show the new military tactics, neither for attack neither for defense. At most, they replaced for maritime lighthouses for signage and help for navigation while the others towers were abandoned.

Boston, Massachusetts, 1797 (Image 4 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: An accurate plan of the town of Boston and its vicinity : exhibiting a ground plan of all the streets, lanes, alleys, wharves, and public buildings in Boston, with the names and description thereof, likewise all the flats and channels between Boston and Charlestown, Cambridge, Roxbury & Dorchester with the two bridges and causeway, and the boundary lines beween Boston and the above mentioned towns from ... by Osgood Carleton ; I. Norman, sc. It was published and sold by Osgood Carleton in 1797. Scale [ca. 1:4,170]. This layer is image 4 of 4 total images, representing the southeast portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, selected public buildings, city ward boundaries, wharves, and more. Relief shown by hachures.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Boston, Massachusetts, 1797 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: An accurate plan of the town of Boston and its vicinity : exhibiting a ground plan of all the streets, lanes, alleys, wharves, and public buildings in Boston, with the names and description thereof, likewise all the flats and channels between Boston and Charlestown, Cambridge, Roxbury & Dorchester with the two bridges and causeway, and the boundary lines beween Boston and the above mentioned towns from ... by Osgood Carleton ; I. Norman, sc. It was published and sold by Osgood Carleton in 1797. Scale [ca. 1:4,170]. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, selected public buildings, city ward boundaries, wharves, and more. Relief shown by hachures.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Boston, Massachusetts, 1797 (Image 1 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: An accurate plan of the town of Boston and its vicinity : exhibiting a ground plan of all the streets, lanes, alleys, wharves, and public buildings in Boston, with the names and description thereof, likewise all the flats and channels between Boston and Charlestown, Cambridge, Roxbury & Dorchester with the two bridges and causeway, and the boundary lines beween Boston and the above mentioned towns from ... by Osgood Carleton ; I. Norman, sc. It was published and sold by Osgood Carleton in 1797. Scale [ca. 1:4,170]. This layer is image 1 of 4 total images, representing the northwest portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, selected public buildings, city ward boundaries, wharves, and more. Relief shown by hachures.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Boston, Massachusetts, 1797 (Image 2 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: An accurate plan of the town of Boston and its vicinity : exhibiting a ground plan of all the streets, lanes, alleys, wharves, and public buildings in Boston, with the names and description thereof, likewise all the flats and channels between Boston and Charlestown, Cambridge, Roxbury & Dorchester with the two bridges and causeway, and the boundary lines beween Boston and the above mentioned towns from ... by Osgood Carleton ; I. Norman, sc. It was published and sold by Osgood Carleton in 1797. Scale [ca. 1:4,170]. This layer is image 2 of 4 total images, representing the northeast portion of the four sheet source map. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, drainage, selected public buildings, city ward boundaries, wharves, and more. Relief shown by hachures.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Birds eye view of trolley routes in New England, 1904 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Trolley wayfinder, birds eye view of trolley routes in New England, published by the New England Street Railway Club, 1904. This is a perspective map not drawn to scale. Covers eastern portion of New England from Lewiston, Maine, to Newport, Rhode Island. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, or other information associated with the principal map. This map shows features such as steam railroads, electric railroads, parks, buildings, drainage, and more. Relief and some features are shown pictorially. Includes 7 insets. This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Essex County, Massachusetts, 1856 (Image 1 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of Essex County, Massachusetts : based upon the trigonometrical survey of the state the details, from actual surveys under the direction of H.F. Walling, superintendent of state map ; engd. by Geo. Worley & Wm. Bracher. It was published by Smith and Morley in 1856. Scale [ca. 1:50,000]. This layer is image 1 of 4 total images, representing the northeast portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.

Essex County, Massachusetts, 1856 (Image 3 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A topographical map of Essex County, Massachusetts : based upon the trigonometrical survey of the state the details, from actual surveys under the direction of H.F. Walling, superintendent of state map ; engd. by Geo. Worley & Wm. Bracher. It was published by Smith and Morley in 1856. Scale [ca. 1:50,000]. This layer is image 3 of 4 total images, representing the southwest portion of the four sheet source map.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Massachusetts State Plane Coordinate System, Mainland Zone (in Feet) (Fipszone 2001). All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as roads, railroads, drainage, public buildings, schools, churches, cemeteries, industry locations (e.g. mills, factories, mines, etc.), private buildings with names of property owners, town and school district boundaries, and more. Relief shown by hachures. It includes many cadastral insets of individual county towns and villages. It also includes illustrations, business directories, and tables of statistics and distances.This layer is part of a selection of digitally scanned and georeferenced historic maps of Massachusetts from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of regions, originators, ground condition dates (1755-1922), scales, and purposes. The digitized selection includes maps of: the state, Massachusetts counties, town surveys, coastal features, real property, parks, cemeteries, railroads, roads, public works projects, etc.