La evolución del paisaje fluvial en la confluencia de los ríos Tajo y Jarama

La tesis doctoral que se presenta realiza un análisis de la evolución del paisaje fluvial de las riberas de los ríos Tajo y Jarama en el entorno de Aranjuez desde una perspectiva múltiple. Contempla y conjuga aspectos naturales, tales como los hidrológicos, geomorfológicos y ecológicos; también culturales, como la regulación hidrológica y la gestión del agua, las intervenciones en cauce y márgenes, la evolución de la propiedad y los cambios de usos del suelo, fundamentalmente. Este análisis ha permitido identificar el sistema de factores, dinámico y complejo, que ha creado este paisaje, así como las interrelaciones, conexiones, condicionantes y dependencias de los descriptores paisajísticos considerados. Por ejemplo, se han estudiado las relaciones cruzadas observadas entre dinámica fluvial-propiedad de la tierra-estado de conservación, cuestiones que hasta la fecha no habían sido tratadas, evaluadas o cuantificadas en otros trabajos dedicados a esta zona. La investigación se ha organizado en tres fases fundamentales que han dado lugar a los capítulos centrales del documento (capítulos 2, 3 y 4). En primer lugar, se ha realizado una caracterización de los factores, naturales y culturales, que organizan el paisaje de este territorio eminentemente fluvial (geomorfología, factores climáticos e hidrológicos, vegetación, propiedad de la tierra y elementos culturales de significación paisajística). A continuación, se ha realizado el estudio de la evolución del paisaje fluvial mediante el análisis de diversos elementos, previamente identificados y caracterizados. Para ello se han procesado imágenes aéreas correspondientes a cinco series temporales así como varios planos antiguos, obteniendo una amplia base de datos que se ha analizado estadísticamente. Finalmente, se han contrastado los resultados parciales obtenidos en los capítulos anteriores, lo que ha permitido identificar relaciones causales entre los factores que organizan el paisaje y la evolución de los elementos que lo constituyen. También, interconexiones entre factores o entre elementos. Este método de trabajo ha resultado muy útil para la comprensión del funcionamiento y evolución de un sistema complejo, como el paisaje de la vega de Aranjuez, un territorio con profundas y antiguas intervenciones culturales donde lo natural, en cualquier caso, siempre subyace. Es posible que la principal aportación de este trabajo, también su diferencia más destacada respecto a otros estudios de paisaje, haya sido mostrar una visión completa y exhaustiva de todos los factores que han intervenido en la conformación y evolución del paisaje fluvial, destacando las relaciones que se establecen entre ellos. Esta manera de proceder puede tener una interesante faceta aplicada, de tal manera que resulta un instrumento muy útil para el diseño de planes de gestión de este territorio fluvial. No en vano, una parte sustancial de la vega del Tajo-Jarama en Aranjuez es un Lugar de Importancia Comunitaria (LIC) y su posterior e ineludible declaración como Zona de Especial Conservación (ZEC) de la Red Natura 2000, de acuerdo con lo establecido en la Directiva 92/43/CE, exige la elaboración de un Plan de Gestión que, en gran medida, podría nutrirse de lo presentado, analizado e interpretado en este trabajo. En este sentido, conviene señalar la conciencia ya asumida de considerar, por su carácter integrador de la realidad territorial, el paisaje como elemento clave para la gestión adecuada de la naturaleza y el territorio. Por otra parte, se considera que los resultados de esta Tesis Doctoral permitirían plantear medidas para la puesta en valor de un paisaje sobresaliente, cuyos límites sobrepasan con creces los que en la actualidad conforman el Paisaje Cultural declarado por la UNESCO. En suma, el análisis de este espacio fluvial realizado con la profundidad y amplitud que permite el método de trabajo seguido puede utilizarse para el diseño de estrategias que dirijan la evolución de este territorio en una línea que garantice su conservación global en términos paisajísticos, patrimoniales y ecológicos, permitiendo además, de este modo, su uso equilibrado como recurso económico, cultural o educativo. This doctoral thesis shows an analysis of fluvial landscape evolution from multiple perspectives on the banks of Tagus and Jarama rivers, around Aranjuez. The thesis contemplates and combines natural features, such as hydrological, geomorphological and ecological features, as well as cultural features, like hydrological regulation and water management, interventions in channels and margins, changes in ownership and land use changes, mainly. This analysis has allowed to identify the factors system, dynamic and complex, that this landscape has created, as well as the interrelationships, connections, constraints and dependencies among considered landscape descriptors. For example, we have studied the relationships observed among fluvial dynamics- land ownership -conservation status, issues not addressed, assessed or quantified up to now in other works about this area. The research is organized into three major phases that led to the paper's central chapters (Chapters 2, 3 and 4). First, there has been a characterization of the factors, both natural and cultural, that organize the landscape of this predominantly fluvial area (geomorphology, climate and hydrological factors, vegetation, land and cultural elements of landscape significance). Then, it was made to study of fluvial landscape evolution by analyzing various elements previously identified and characterized. Aerial images were processed for five series and several old maps, obtaining an extensive database, that has been analyzed statistically. Finally, we have contrasted the partial results obtained in the previous chapters, making it possible to identify causal relationships between the factors that organize the landscape and the evolution of the elements that constitute it. This working method has been very useful for understanding the operation and evolution of a complex system, as the landscape of the Vega de Aranjuez, a territory with deep and ancient cultural interventions where anyway, nature feature always lies. It is possible that the main contribution of this work, also its most prominent difference compared with other studies of landscape, has been to show a complete and exhaustive view of all factors involved in the formation and evolution of the fluvial landscape, highlighting the relationships established among them. This approach could have an interesting applied facet, so that is a very useful tool for designing management plans on this river territory. Not surprisingly, a substantial part of the valley of the Tagus-Jarama in Aranjuez is a Site of Community Importance (SCI) and their subsequent and inevitable declaration as Special Area of Conservation (SAC) of the Natura 2000 network, in accordance with the provisions Directive 92/43/EC, requires the development of a management plan that largely could draw on what was presented, analyzed and interpreted in this paper. In this regard, it should be noted conscience and assumed to consider, on the inclusiveness of territorial reality, the landscape as a key element for the proper management of nature and territory. On the other hand, it is considered that the results of this thesis allow to propose measures for enhancement of outstanding scenery, which go well beyond the boundaries that currently the Cultural Landscape declared by UNESCO. In sum, the analysis of this river area made with the depth and breadth that enables working method can be used to design strategies that address the evolution of this territory in a line that guarantees global conservation landscape terms, heritage and ecological, also, allowing its use as a balancing economic, cultural or educational resource.

Discrete linear stability and sensitivity analysis of fluid flows

Este trabajo presenta un método discreto para el cálculo de estabilidad hidrodinámica y análisis de sensibilidad a perturbaciones externas para ecuaciones diferenciales y en particular para las ecuaciones de Navier-Stokes compressible. Se utiliza una aproximación con variable compleja para obtener una precisión analítica en la evaluación de la matriz Jacobiana. Además, mapas de sensibilidad para la sensibilidad a las modificaciones del flujo de base y a una fuerza constante permiten identificar las regiones del campo fluido donde una modificacin (ej. fuerza puntual) tiene un efecto estabilizador del flujo. Se presentan cuatro casos de prueba: (1) un caso analítico para comprobar la derivación discreta, (2) una cavidad cerrada a bajo Reynolds para mostrar la mayor precisión en el cálculo de los valores propios con la aproximación de paso complejo, (3) flujo 2D en un cilindro circular para validar la metodología, y (4) flujo en un cavidad abierta, presentado para validar el método en casos de inestabilidades convectivamente inestables. Los tres últimos casos mencionados (2-4) se resolvieron con las ecuaciones de Navier-Stokes compresibles, utilizando un método Discontinuous Galerkin Spectral Element Method. Se obtuvo una buena concordancia para el caso de validación (3), cuando se comparó el nuevo método con resultados de la literatura. Además, este trabajo muestra que para el cálculo de los modos propios directos y adjuntos, así como para los mapas de sensibilidad, el uso de variables complejas es de suprema importancia para obtener una predicción precisa. El método descrito es aplicado al análisis para la estabilización de la estela generada por un disco actuador, que representa un modelo sencillo para hélices, rotores de helicópteros o turbinas eólicas. Se explora la primera bifurcación del flujo para un disco actuador, y se sugiere que está asociada a una inestabilidad de tipo Kelvin-Helmholtz, cuya estabilidad se controla con en el número de Reynolds y en la resistencia del disco actuador (o fuerza resistente). En primer lugar, se verifica que la disminución de la resistencia del disco tiene un efecto estabilizador parecido a una disminución del Reynolds. En segundo lugar, el análisis hidrodinmico discreto identifica dos regiones para la colocación de una fuerza puntual que controle las inestabilidades, una cerca del disco y otra en una zona aguas abajo. En tercer lugar, se muestra que la inclusión de un forzamiento localizado cerca del actuador produce una estabilización más eficiente que al forzar aguas abajo. El análisis de los campos de flujo controlados confirma que modificando el gradiente de velocidad cerca del actuador es más eficiente para estabilizar la estela. Estos resultados podrían proporcionar nuevas directrices para la estabilización de la estela de turbinas de viento o de marea cuando estén instaladas en un parque eólico y minimizar las interacciones no estacionarias entre turbinas. ABSTRACT A discrete framework for computing the global stability and sensitivity analysis to external perturbations for any set of partial differential equations is presented. In particular, a complex-step approximation is used to achieve near analytical accuracy for the evaluation of the Jacobian matrix. Sensitivity maps for the sensitivity to base flow modifications and to a steady force are computed to identify regions of the flow field where an input could have a stabilising effect. Four test cases are presented: (1) an analytical test case to prove the theory of the discrete framework, (2) a lid-driven cavity at low Reynolds case to show the improved accuracy in the calculation of the eigenvalues when using the complex-step approximation, (3) the 2D flow past a circular cylinder at just below the critical Reynolds number is used to validate the methodology, and finally, (4) the flow past an open cavity is presented to give an example of the discrete method applied to a convectively unstable case. The latter three (2–4) of the aforementioned cases were solved with the 2D compressible Navier–Stokes equations using a Discontinuous Galerkin Spectral Element Method. Good agreement was obtained for the validation test case, (3), with appropriate results in the literature. Furthermore, it is shown that for the calculation of the direct and adjoint eigenmodes and their sensitivity maps to external perturbations, the use of complex variables is paramount for obtaining an accurate prediction. An analysis for stabilising the wake past an actuator disc, which represents a simple model for propellers, helicopter rotors or wind turbines is also presented. We explore the first flow bifurcation for an actuator disc and it suggests that it is associated to a Kelvin- Helmholtz type instability whose stability relies on the Reynolds number and the flow resistance applied through the disc (or actuator forcing). First, we report that decreasing the disc resistance has a similar stabilising effect to an decrease in the Reynolds number. Second, a discrete sensitivity analysis identifies two regions for suitable placement of flow control forcing, one close to the disc and one far downstream where the instability originates. Third, we show that adding a localised forcing close to the actuator provides more stabilisation that forcing far downstream. The analysis of the controlled flow fields, confirms that modifying the velocity gradient close to the actuator is more efficient to stabilise the wake than controlling the sheared flow far downstream. An interesting application of these results is to provide guidelines for stabilising the wake of wind or tidal turbines when placed in an energy farm to minimise unsteady interactions.

Macroecología y ecoinformática: sesgos, errores y predicciones en el modelado de distribuciones

Hoy en día es común estudiar los patrones globales de biodiversidad a partir de las predicciones generadas por diferentes modelos de nicho ecológico. Habitualmente, estos modelos se calibran con datos procedentes de bases de datos de libre acceso (e.g. GBIF). Sin embargo, a pesar de la facilidad de descarga y de la accesibilidad de los datos, la información almacenada sobre las localidades donde están presentes las especies suele tener sesgos y errores. Estos problemas en los datos de calibración pueden modificar drásticamente las predicciones de los modelos y con ello pueden enmascarar los patrones macroecológicos reales. El objetivo de este trabajo es investigar qué métodos producen resultados más precisos cuando los datos de calibración incluyen sesgos y cuáles producen mejores resultados cuando los datos de calibración tienen, además de sesgos, errores. Para ello creado una especie virtual, hemos proyectado su distribución en la península ibérica, hemos muestreado su distribución de manera sesgada y hemos calibrado dos tipos de modelos de distribución (Bioclim y Maxent) con muestras de distintos tamaños. Nuestros resultados indican que cuando los datos sólo están sesgados, los resultados de Bioclim son mejores que los de Maxent. Sin embargo, Bioclim es extremadamente sensible a la presencia de errores en los datos de calibración. En estas situaciones, el comportamiento de Maxent es mucho más robusto y las predicciones que proporciona son más ajustadas.

Casco Bay, Maine, Nautical Chart, 1776 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Rogers, Bay, Segadahock River, New Meadow, harbour, Mericonig Sound, Middle Bay, Magout Bay, Portland Island, etc.] (sheet originally published in 1776). The map is [sheet 30] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the eastern portion of the map. Covers the Coast of Maine, Casco Bay, from Portland to Seguin Island. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, buildings, and roads. Relief is shown by hachures; depths by soundings and shading. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Casco Bay, Maine, Nautical Chart, 1776 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Rogers, Bay, Segadahock River, New Meadow, harbour, Mericonig Sound, Middle Bay, Magout Bay, Portland Island, etc.] (sheet originally published in 1776). The map is [sheet 31] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 2 of 2 total images of the two sheet source map, representing the western portion of the map. Covers the Coast of Maine, Casco Bay, from Portland to Seguin Island. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, buildings, and roads. Relief is shown by hachures; depths by soundings and shading. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Entrance to Penobscot Bay, Maine, Nautical Chart, 1776 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [Entrance to Penobscot Bay] (sheet originally published in 1776). The map is [sheet 38] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the western portion of the map. Covers a portion of Penobscot Bay, Maine. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Entrance to Penobscot Bay, Maine, Nautical Chart, 1776 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [Entrance to Penobscot Bay] (sheet originally published in 1776). The map is [sheet 39] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 2 of 2 total images of the two sheet source map, representing the eastern portion of the map. Covers a portion of Penobscot Bay, Maine. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Upper Penobscot Bay, Maine, Nautical Chart, 1776 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Great Bluehill Bay, Penobscot River &c.] (sheet originally published in 1776). The map is [sheet 40] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the western portion of the map. Covers a portion of Penobscot Bay, including Belfast Bay and Penobscot River, Maine. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Upper Penobscot Bay, Maine, Nautical Chart, 1776 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Great Bluehill Bay, Penobscot River &c.] (sheet originally published in 1776). The map is [sheet 41] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 2 of 2 total images of the two sheet source map, representing the eastern portion of the map. Covers a portion of Penobscot Bay, including Blue Hill Bay, Deer Island, and Eggemoggin Reach, Maine. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Maine Coast, Gouldsboro Bay to Moose Cove, Nautical Chart, 1776 (Image 1 of 3) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Mechios, Pleasant Bay, Naraguagus River, Pigeonhill Bay, Goldsborough &c.] (sheet originally published in 1776). The map is [sheet 44] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 1 of 3 total images of the three sheet source map, representing the western portion of the map. Covers the coast of Maine from Gouldsboro Bay to Cape Split. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Maine Coast, Gouldsboro Bay to Moose Cove, Nautical Chart, 1776 (Image 3 of 3) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [A chart of Mechios, Pleasant Bay, Naraguagus River, Pigeonhill Bay, Goldsborough &c.] (sheet originally published in 1776). The map is [sheet 46] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:50,000]. This layer is image 3 of 3 total images of the three sheet source map, representing the western portion of the map. Covers the coast of Maine from Machias Bay to Moose Cove. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns, and buildings. Relief is shown by hachures; depths by soundings. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Coast of Rhode Island, Connecticut and Long Island, New York, Nautical Chart, 1779 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [Coast of New England from Point Judith, Rhode Island, to Great Bay, Long Island] (sheet originally published in 1779). The map is [sheet 3] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:128,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the western portion of the map. Covers portions of Long Island Sound and the coasts of Long Island, New York (including Gardiners Island and Plum Island) and Connecticut near New London. The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns. Relief is shown by hachures; depths by soundings and shading. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.

Coast of Rhode Island, Connecticut and Long Island, New York, Nautical Chart, 1779 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the untitled, historic nautical chart: [Coast of New England from Point Judith, Rhode Island, to Great Bay, Long Island] (sheet originally published in 1779). The map is [sheet 4] from the Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England, from surveys taken by Samuel Holland and published by J.F.W. Des Barres, 1781. Scale [ca. 1:128,000]. This layer is image 2 of 2 total images of the two sheet source map, representing the eastern portion of the map. Covers portions of Long Island Sound and the coasts of Long Island (Montauk Point), New York, Connecticut, and Rhode Island (including Block Island and Narragansett Bay). The image is georeferenced to the surface of the earth and fit to the 'World Mercator' (WGS 84) projected coordinate system. All map collar 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 coastal features such as harbors, inlets, rocks, channels, points, coves, shoals, islands, and more. Includes also selected land features such as cities and towns. Relief is shown by hachures; depths by soundings and shading. This layer is part of a selection of digitally scanned and georeferenced historic maps from The Harvard Map Collection. The entire Atlantic Neptune atlas Vol. 3 : Charts of the coast and harbors of New England has been scanned and georeferenced as part of this selection.