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44-572: The system is hydrographically important, as it separates the watersheds of most of the major rivers in Spain and Portugal , including the Ebro basin to the east from the basins of the Douro , Tagus , Guadiana ( Záncara - Gigüela ), Júcar and Turia to the west and south. There are important mining areas in some of the ranges such as Sierra Menera , Sierra de Arcos and Sierra de San Just , making

88-782: A carnivorous plant that does not grow further south in Western Europe. Centaurea pinnata is an endangered species of plant present in the Sierra de Vicort and Sierra de Santa Cruz mountain ranges. The Sistema Ibérico comprises several mountain ranges and massifs: The main peaks of the system are: Moncayo (2,313 m), Monte San Lorenzo (2,262 m), Pico de Urbión (2,228 m), Pico San Millán (2,131 m), Peña Cebollera (2,129 m), Javalambre (2,020 m) and Peñarroya (2,019 m). Other locally important summits are Cerro Calderón (1,837 m), Mont Caro (1,441 m), Tossal d'Orenga (1,144 m) and Montegordo (837 m), The Sistema Ibérico

132-675: A kestrel . When it soars it does so on flattish wings. This is an Old World species found throughout the Mediterranean basin, into Russia and the Middle East , and parts of Western Asia , and in the Indian Subcontinent and also further east in some Indonesian islands. Those present on the northern edge of the Mediterranean and other parts of Europe migrate mainly to sub-Saharan Africa north of

176-464: A great number of surviving towns have only a residual population. In some cases, many of the inhabitants are not natives anymore but immigrants from Romania or the Maghreb working as contract laborers in agricultural activities. The exodus from the rural mountainous areas in Spain rose after General Franco 's Stabilization Plan in 1959. The population declined steeply as people emigrated towards

220-489: A hazard to navigation such as rocks, shoals , reefs and other features that obstruct ship passage. Bottom measurements also include collection of the nature of the bottom as it pertains to effective anchoring. Unlike oceanography, hydrography will include shore features, natural and manmade, that aid in navigation. Therefore, a hydrographic survey may include the accurate positions and representations of hills , mountains and even lights and towers that will aid in fixing

264-421: A preference for multi-use surveys, so that the same data collected for nautical charting purposes can also be used for bathymetric portrayal. Even though, in places, hydrographic survey data may be collected in sufficient detail to portray bottom topography in some areas, hydrographic charts only show depth information relevant for safe navigation and should not be considered as a product that accurately portrays

308-621: A remit to gather and distribute charts to HM Ships. Within a year existing charts from the previous two centuries had been collated, and the first catalog published. The first chart produced under the direction of the Admiralty , was a chart of Quiberon Bay in Brittany , and it appeared in 1800. Under Captain Thomas Hurd the department received its first professional guidelines, and the first catalogs were published and made available to

352-640: A sectional flow rate of moving water through a section and or current. Uncrewed Surface Vessels (USVs) and are commonly used for hydrographic surveys - they are often equipped with some sort of sonar. Single-beam echosounders, multibeam echosounders , and side scan sonars are all frequently used in hydrographic applications. The knowledge gained from these surveys aid in disaster planning, port and harbor maintenance, and various other coastal planning activities. Hydrographic services in most countries are carried out by specialized hydrographic offices . The international coordination of hydrographic efforts lies with

396-488: A ship's position, as well as the physical aspects of the sea and seabed. Hydrography, mostly for reasons of safety, adopted a number of conventions that have affected its portrayal of the data on nautical charts. For example, hydrographic charts are designed to portray what is safe for navigation, and therefore will usually tend to maintain least depths and occasionally de-emphasize the actual submarine topography that would be portrayed on bathymetric charts . The former are

440-488: A steep decline in numbers and range in Europe and is now rare and still decreasing in several countries due to changes in agriculture and land use. It needs protection. In the middle and far eastern part of its range, this species is not yet threatened. In his description of the species, Buffon says that he kept one of these eagles in captivity and observed its behavior. The captive bird ate mice and frogs, and he states that

484-492: A type of hawk, and aetos , "eagle". The specific gallicus means "of Gallia ". The short-toed snake eagle was formally described in 1788 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus 's Systema Naturae . He placed it with the falcons, eagles and their relatives in the genus Falco and coined the binomial name Falco gallicus . Gmelin based his description on

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528-438: Is Latin for "Gaul" ie France. Two subspecies are recognised: These are relatively large snake eagles. Adults are 59 to 70 cm (23 to 28 in) long with a 162 to 195 cm (5 ft 4 in to 6 ft 5 in) wingspan and weigh 1.2–2.3 kg (2.6–5.1 lb), an average weight for the species is about 1.7 kg (3.7 lb). They can be recognised in the field by their predominantly white underside,

572-496: Is more commonly called hydrometry or hydrology . Hydrography of rivers and streams is also an integral part of water management. Most reservoirs in the United States use dedicated stream gauging and rating tables to determine inflows into the reservoir and outflows to irrigation districts, water municipalities and other users of captured water. River/stream hydrographers use handheld and bank mounted devices, to capture

616-452: Is mostly reptiles, mainly snakes , but also some lizards . Sometimes they become entangled with larger snakes and battle on the ground. Occasionally, they prey on small mammals up to the size of a rabbit, and rarely birds and large insects. This eagle is generally very silent. On occasions, it emits a variety of musical whistling notes. When breeding, it lays only one egg. It can live up to 17 years. The short-toed snake eagle has suffered

660-630: Is not as high as other mountain systems in Spain. It is, however, very significant from the hydrographic point of view for important rivers of the Iberian Peninsula have their source in its mountains, which divide the Atlantic from the Mediterranean watershed . The following rivers rise in the Sistema Ibérico: Hydrography Hydrography is the branch of applied sciences which deals with

704-584: Is rarely found in the mountainous areas. Aquatic invertebrates, including the Austropotamobius pallipes crayfish, and certain fishes, such as Salaria fluviatilis and Cobitis paludica are common in the upper course of the Sistema Ibérico rivers. Some mountain streams have been stocked with trout . Traditional cattle rearing activities, formerly so important in central Iberia, still survive on dry grasslands in certain villages around

748-630: The International Hydrographic Organization . The United Kingdom Hydrographic Office is one of the oldest, supplying a wide range of charts covering the globe to other countries, allied military organizations and the public. In the United States, the hydrographic charting function has been carried out since 1807 by the Office of Coast Survey of the National Oceanic and Atmospheric Administration within

792-818: The Mediterranean coast. This system runs northwest-southeast between the Ebro plain and the Meseta Central for over 500 km, from the La Bureba corridor in Burgos Province close to the Cordillera Cantábrica to the Mediterranean sea close to Valencia in the south and close to Tortosa and the Ebro Delta in the east. The bulk of the Sistema Ibérico is located in the southern half of Aragon . The Prebaetic System rises south of

836-489: The U.S. Department of Commerce and the U.S. Army Corps of Engineers . Circaetus gallicus The short-toed snake eagle ( Circaetus gallicus ), also known as the short-toed eagle , is a medium-sized bird of prey in the family Accipitridae , which also includes many other diurnal raptors such as kites , buzzards and harriers . The genus name Circaetus is from the Ancient Greek kirkos ,

880-941: The equator , leaving in September/October and returning in April/May. In the Middle and Far East the populations are resident. In Europe, it is most numerous in Spain where it is fairly common but elsewhere it is rare in many parts of its range. A bird on the Isles of Scilly , Britain , in October 1999 was the first confirmed record for that country. The short-toed snake eagle is found in open cultivated plains, arid stony deciduous scrub areas and foothills and semi-desert areas. It requires trees for nesting and open habitats, such as cultivations and grasslands for foraging. Its prey

924-422: The mariner 's tools to avoid accident. The latter are best representations of the actual seabed, as in a topographic map, for scientific and other purposes. Trends in hydrographic practice since c. 2003–2005 have led to a narrowing of this difference, with many more hydrographic offices maintaining "best observed" databases, and then making navigationally "safe" products as required. This has been coupled with

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968-671: The "Jean le Blanc" that had been described by the English ornithologist John Latham and the French ornithologists Mathurin Jacques Brisson and the Comte de Buffon . The short-toed snake eagle is now placed in the genus Circaetus that was introduced in 1816 by the French ornithologist Louis Pierre Vieillot . The genus name is from the Ancient Greek kirkos , a type of hawk, and aetos , "eagle". The specific epithet gallicus

1012-584: The Iberian System are Lacerta lepida , Psammodromus algirus , Psammodromus hispanicus , Podarcis muralis and Podarcis hispanicus . Chalcides chalcides , Chalcides bedriagai and Anguis fragilis , are relatively rarer. The snakes present in these mountains are Natrix maura , Natrix natrix , Malpolon monspessulanus , Elaphe scalaris , Coronella girondica , Coronella austriaca and Vipera latastei . Some amphibians are abundant in or near ponds and rivulets throughout

1056-458: The actual shape of the bottom. The soundings selected from the raw source depth data for placement on the nautical chart are selected for safe navigation and are biased to show predominantly the shallowest depths that relate to safe navigation. For instance, if there is a deep area that can not be reached because it is surrounded by shallow water, the deep area may not be shown. The color filled areas that show different ranges of shallow water are not

1100-513: The area. Some of the parts of the system stand geologically isolated, interrupting the continuity of the whole, linked to the other parts through high plateaus of varying altitudes. Large zones of the mountainous Iberian System have undergone heavy depopulation since the early 20th century. There are many ghost towns and abandoned villages scattered across different parts of the Iberian System, especially in Teruel Province . Currently

1144-536: The best data available and will caveat its nature in a caution note or in the legend of the chart. A hydrographic survey is quite different from a bathymetric survey in some important respects, particularly in a bias toward least depths due to the safety requirements of the former and geomorphologic descriptive requirements of the latter. Historically, this could include echosoundings being conducted under settings biased toward least depths, but in modern practice hydrographic surveys typically attempt to best measure

1188-507: The data are interchangeable, but marine hydrographic data will be particularly directed toward marine navigation and safety of that navigation. Marine resource exploration and exploitation is a significant application of hydrography, principally focused on the search for hydrocarbons . Hydrographical measurements include the tidal , current and wave information of physical oceanography. They include bottom measurements, with particular emphasis on those marine geographical features that pose

1232-403: The depths observed, with the adjustments for navigational safety being applied after the fact. Hydrography of streams will include information on the stream bed, flows , water quality and surrounding land. Basin or interior hydrography pays special attention to rivers and potable water although if collected data is not for ship navigational uses, and is intended for scientific usage, it

1276-519: The entire world, and produced over 130,000 charts annually, of which about half were sold. The word hydrography comes from the Ancient Greek ὕδωρ ( hydor ), "water" and γράφω ( graphō ), "to write". Large-scale hydrography is usually undertaken by national or international organizations which sponsor data collection through precise surveys and publish charts and descriptive material for navigational purposes. The science of oceanography is, in part, an outgrowth of classical hydrography. In many respects

1320-495: The equivalent of contours on a topographic map since they are often drawn seaward of the actual shallowest depth portrayed. A bathymetric chart does show marine topology accurately. Details covering the above limitations can be found in Part ;1 of Bowditch's American Practical Navigator . Another concept that affects safe navigation is the sparsity of detailed depth data from high resolution sonar systems. In more remote areas,

1364-494: The establishment of the United Kingdom Hydrographic Office , Royal Navy captains were responsible for the provision of their own charts. In practice this meant that ships often sailed with inadequate information for safe navigation, and that when new areas were surveyed, the data rarely reached all those who needed it. The Admiralty appointed Alexander Dalrymple as Hydrographer in 1795, with

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1408-466: The industrial areas of the large cities and the coastal towns where the tourism industry was growing. Other causes of high emigration have been the abandonment by the local youth of traditional agricultural practices that were the mainstay of the village economy, such as sheep and goat rearing, as well as the lifestyle changes that swept over rural Spain during the second half of the 20th century. The heavy depopulation has favored wildlife so that one of

1452-507: The last colonies of griffon vultures in Europe is in the Iberian System. Wolves and eagles ( Aquila chrysaetos , Hieraaetus fasciatus , Hieraaetus pennatus , Circaetus gallicus ) are also relatively common in the lonely heights. Among the mammals, the Spanish ibex , roe deer , wild boar , European badgers , common genets , among others, have their habitat in many of these desolate mountain ranges. The most common reptiles in

1496-402: The making of charts to aid navigation, by individual mariners as they navigated into new waters. These were usually the private property, even closely held secrets, of individuals who used them for commercial or military advantage. As transoceanic trade and exploration increased, hydrographic surveys started to be carried out as an exercise in their own right, and the commissioning of surveys

1540-411: The measurement and description of the physical features of oceans , seas , coastal areas , lakes and rivers , as well as with the prediction of their change over time, for the primary purpose of safety of navigation and in support of all other marine activities, including economic development, security and defense, scientific research, and environmental protection. The origins of hydrography lay in

1584-502: The only available depth information has been collected with lead lines. This collection method drops a weighted line to the bottom at intervals and records the depth, often from a rowboat or sail boat. There is no data between soundings or between sounding lines to guarantee that there is not a hazard such as a wreck or a coral head waiting there to ruin a sailor's day. Often, the navigation of the collecting boat does not match today's GPS navigational accuracies. The hydrographic chart will use

1628-467: The public and to other nations as well. In 1829, Rear-Admiral Sir Francis Beaufort , as Hydrographer, developed the eponymous Scale , and introduced the first official tide tables in 1833 and the first " Notices to Mariners " in 1834. The Hydrographic Office underwent steady expansion throughout the 19th century; by 1855, the Chart Catalogue listed 1,981 charts giving a definitive coverage over

1672-635: The southern slopes are drier than the northern ones and may be subject to wildfires in periods of prolonged drought, especially in the summer. Bogs are not common in the Iberian Peninsula, but high altitude bogs form in the few areas of the Sistema Ibérico where the water remains stagnant, such as near Orihuela del Tremedal , Bronchales and in the place known as Fuente del Hierro , at an altitude between 1.400 and 1.550 m. The plants growing in these bogs are mainly Polytrichum mosses, Potentilla erecta , Pinguicula vulgaris , Vaccinium myrtillus , Calluna vulgaris , and also Drosera rotundifolia ,

1716-403: The southernmost end of the Iberian System. The geology of the Iberian System is complex, for it can hardly be defined as a homogeneous system. It is composed of a haphazard and motley series of mountain ranges , massifs , plateaus and depressions without a definite common petrologic composition and overall structure. Nummulite limestone , marble and sandstone are common throughout

1760-462: The system one of the chief mining regions in Spain since ancient times. One of the comarcas of Aragon located in the Iberian System was given the name of Cuencas Mineras , lit. 'Mining Basins', since mining is the main activity in the comarca. The Sistema Ibérico mountain range borders the Meseta Central on its eastern end and separates the Meseta Central from the Ebro valley and from

1804-899: The system. There are also many hunters visiting some of the ranges, mainly those that are relatively closer to the urban areas and especially on weekends. Some ranges have forested patches, consisting mainly of Pinus pinaster , Pinus sylvestris and Pinus uncinata pines and Quercus rotundifolia , Quercus pyrenaica and Quercus faginea oaks, even Fagus sylvatica beeches and Betula pendula birches grow in some humid slopes, where Pteridium aquilinum , Polypodium vulgare ferns may also be found. Other ranges are rocky and quite bare with heath ( Erica arborea , Erica vagans , Calluna vulgaris ), broom as well as thyme and Festuca and Nardus stricta grasslands. Thin forest or shrubland may include Juniperus communis , Juniperus thurifera , Cytisus purgans , Erinacea anthyllis and Calluna vulgaris shrub . Often

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1848-540: The upper parts being greyish brown. The chin, throat and upper breast are a pale, earthy brown. The tail has 3 or 4 bars. Additional indications are an owl -like rounded head, brightly yellow eyes and lightly barred under wing. The short-toed snake eagle spends more time on the wing than do most members of its genus. It favours soaring over hill slopes and hilltops on updraughts, and it does much of its hunting from this position at heights of up to 500 m (1,600 ft). When quartering open country it frequently hovers like

1892-444: The whole system, such as Rana perezi , Bufo bufo , Bufo calamita , Alytes obstetricans , Triturus marmoratus and Lissotriton helveticus , the latter also at high altitude, whether in intermittent or permanent bodies of water. Hyla arborea and Salamandra salamandra are somewhat rarer, but still having a wide distribution, especially in humid forested zones. The Iberian ribbed newt ( Pleurodeles waltl ) , however,

1936-451: Was increasingly done by governments and special hydrographic offices. National organizations, particularly navies , realized that the collection, systematization and distribution of this knowledge gave it great organizational and military advantages. Thus were born dedicated national hydrographic organizations for the collection, organization, publication and distribution of hydrography incorporated into charts and sailing directions. Prior to

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