Brač is an island in the Adriatic Sea within Croatia, with an area of 396 square kilometres, making it the largest island in Dalmatia, the third largest in the Adriatic. It is separated from the mainland by the Brač Channel, 5 to 13 km wide; the island's tallest peak, Vidova gora, or Mount St. Vid, stands at 780 m, making it the highest island point in the Adriatic; the island has a population of 13,956, living in numerous settlements, ranging from the main town Supetar, with more than 3,300 inhabitants, to Murvica, where less than two dozen people live. Brač Airport on Brač is the largest airport of all islands surrounding Split. Archaeological findings in the Kopačina cave between Supetar and Donji Humac have been dated to the 12th millennium BC; these are some of the oldest traces of human habitation in Croatia. The findings show that the cave has been inhabited until the 3rd millennium BC; some of the artefacts have originated in the Dalmatian hinterland, showing that Brač was part of a trade network with the mainland.
In the Bronze Age and Iron Age, numerous villages existed. In the 4th century BC Greek colonisation spread over many Adriatic islands and along the coast, but none of them on Brač. Greeks visited the island and traded with the Illyrian inhabitants; the Greek name of the island was Elaphousa derived from elaphos "stag". Based on this, it has been speculated that the original name of the island may have been derived from Messapic *brentos "stag". Polybius and Plinius record the name of the island as Brattia. Brač lay on the crossroads of several trade routes from Salona to the Po River. Greek artifacts were found in the bay of Vičja near Ložišća on the estate of the Rakela-Bugre brothers. Many of the objects belonging to this still unexamined site are now on display in the Archeological Museum of Split. Dalmatia fell under Roman rule in AD 9. Salona became the capital of the new province and because of its proximity to Salona, significant population centers were present on the island in the Roman period.
Signs of Roman habitation are still widespread, but they are limited to single Roman villas and early quarries between Škrip and Splitska. Splitska became the most important harbour to carry stone to Salona and the whole of Dalmatia. Diocletian's Palace, which became Split, was built with limestone, quarried on Brač. Agriculture wine and olives, began in the same era. After the destruction of Salona by Avars and Slavs, Brač became a refuge. Tradition has it that Škrip was founded by refugee Salonans, but the town is much older than that. In 872, the island was sacked by Saracen raiders. From 1268 to 1357 the island recognised the supremacy of the Republic of Venice, after that they bowed to the Kingdom of Hungary. In the summer of 1390, together with the whole region, they accepted the rule of the Bosnian King Tvrtko Kotromanić, who died the next year. Soon after his death, Hungary claimed the island again. In this whole period, they kept their basic autonomy and old structures - the island was never rich or strategically interesting enough to justify serious intervention.
Local nobility administered and ruled Brač and the seat of the council was Nerežišća in the island's center. The leader was selected from the noble families. Only in 1420 did the Venetian Republic reclaim the island sending a representative to assume rule over it; the Black Death hit Brač from 1434-1436. For 1405, Hranković mentions in his chronicles that Brač has a population of 6,000 - but after the pandemic, only 2,000 people were still living on the island; the population recovered in the following years with many people moving in from the main land and the population spreading from the inner parts of the island to the coast, where some of the old pre-Croatian settlements were resettled again. During this time, the Bosnian realm fell to the Ottoman Empire and many refugees settled on the islands on Brač. Many towns were founded in that time and the population began moving from the interior of the island to its coast: to Bol, Postira, Povlja, Pučišća, Sumartin, Supetar i Sutivan. Venice ruled for more than four centuries, until 1797, when the Habsburg Monarchy annexed most of its territory in a deal with Napoleonic France.
The official language was Latin. During the Napoleonic Wars, Brač was conquered by the French Empire for a short time in 1806. In 1807, Prince-Bishop Petar I Njegoš of Montenegro managed to seize Brač with the help of the Russian navy, however at the Congress of Vienna in 1815 the island was returned to the Austrian Empire. In 1827, the administrative center of Brač moved from Nerežišća to Supetar. Brač was incorporated into the Austrian crownland of Dalmatia from and became a part of Cisleithania of the Monarchy of Austria-Hungary from 1867. After the fall of Austria-Hungary 1918, Brač became part of the Kingdom of Serbs and Slovenes, or Yugoslavia since 1929. In 1939 an autonomous Croatian Banate was created; the population of the island drastically decreased in the beginning of the 20th century due to heavy emigration to Latin America Argentina and Chile, to New Zealand and Australia. The emigration continued during the whole century, only generations preferring to move to European countries Germany.
Among others, the Chilean writer Antonio Skármeta is descended from such immigrants. In 1941 Italian forces occupied the island. In the mountainous regions of the island, native rebels fought a quite effective guer
The Baltic Sea is a marginal sea of the Atlantic Ocean, enclosed by Denmark, Finland, Lithuania, northeast Germany, Poland and the North and Central European Plain. The sea stretches from 53 ° N from 10 ° E to 30 ° E longitude. A mediterranean sea of the Atlantic, with limited water exchange between the two bodies, the Baltic Sea drains through the Danish islands into the Kattegat by way of the straits of Øresund, the Great Belt, the Little Belt, it includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga, the Bay of Gdańsk. The Baltic Proper is bordered on its northern edge, at the latitude 60°N, by the Åland islands and the Gulf of Bothnia, on its northeastern edge by the Gulf of Finland, on its eastern edge by the Gulf of Riga, in the west by the Swedish part of the southern Scandinavian Peninsula; the Baltic Sea is connected by artificial waterways to the White Sea via the White Sea Canal and to the German Bight of the North Sea via the Kiel Canal. Administration The Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area includes the Baltic Sea and the Kattegat, without calling Kattegat a part of the Baltic Sea, "For the purposes of this Convention the'Baltic Sea Area' shall be the Baltic Sea and the Entrance to the Baltic Sea, bounded by the parallel of the Skaw in the Skagerrak at 57°44.43'N."Traffic history Historically, the Kingdom of Denmark collected Sound Dues from ships at the border between the ocean and the land-locked Baltic Sea, in tandem: in the Øresund at Kronborg castle near Helsingør.
The narrowest part of Little Belt is the "Middelfart Sund" near Middelfart. Oceanography Geographers agree that the preferred physical border of the Baltic is a line drawn through the southern Danish islands, Drogden-Sill and Langeland; the Drogden Sill is situated north of Køge Bugt and connects Dragør in the south of Copenhagen to Malmö. By this definition, the Danish Straits are part of the entrance, but the Bay of Mecklenburg and the Bay of Kiel are parts of the Baltic Sea. Another usual border is the line between Falsterbo and Stevns Klint, Denmark, as this is the southern border of Øresund. It's the border between the shallow southern Øresund and notably deeper water. Hydrography and biology Drogden Sill sets a limit to Øresund and Darss Sill, a limit to the Belt Sea; the shallow sills are obstacles to the flow of heavy salt water from the Kattegat into the basins around Bornholm and Gotland. The Kattegat and the southwestern Baltic Sea have a rich biology; the remainder of the Sea is poor in oxygen and in species.
Thus, the more of the entrance, included in its definition, the healthier the Baltic appears. Tacitus called it Mare Suebicum after the Germanic people of the Suebi, Ptolemy Sarmatian Ocean after the Sarmatians, but the first to name it the Baltic Sea was the eleventh-century German chronicler Adam of Bremen; the origin of the latter name is speculative and it was adopted into Slavic and Finnic languages spoken around the sea likely due to the role of Medieval Latin in cartography. It might be connected to the Germanic word belt, a name used for two of the Danish straits, the Belts, while others claim it to be directly derived from the source of the Germanic word, Latin balteus "belt". Adam of Bremen himself compared the sea with a belt, stating that it is so named because it stretches through the land as a belt, he might have been influenced by the name of a legendary island mentioned in the Natural History of Pliny the Elder. Pliny mentions an island named Baltia with reference to accounts of Xenophon.
It is possible. Baltia might be derived from belt and mean "near belt of sea, strait." Meanwhile, others have suggested that the name of the island originates from the Proto-Indo-European root *bhel meaning "white, fair". This root and its basic meaning were retained in both Latvian. On this basis, a related hypothesis holds that the name originated from this Indo-European root via a Baltic language such as Lithuanian. Another explanation is that, while derived from the aforementioned root, the name of the sea is related to names for various forms of water and related substances in several European languages, that might have been associated with colors found in swamps, yet another explanation is that the name meant "enclosed sea, bay" as opposed to open sea. Some Swedish historians believe. In the Middle Ages the sea was known by a variety of names; the name Baltic Sea became dominant only after 1600. Usage of Baltic and similar terms to denote the region east of the sea started only in 19th century.
The Baltic Sea was known in ancient Latin language sources as Mare Suebicum or Mare Germanicum. Older native names in languages that used to be spoken on the shores of the sea or near it indicate the geographical location of the sea, or its size in relation to smaller gulfs, or tribes associated with it. In modern lang
Long Point, Ontario
Long Point is a sand spit and medium-sized hamlet on the north shore of Lake Erie, part of Norfolk County in the province of Ontario, Canada. It is about a kilometre across at its widest point. Lake Erie lies to the south of Long Point, Long Point Bay lies on the north side comprise; the bay is subdivided into the Inner Bay and Outer Bay by a line that runs between Turkey Point to the north and Pottahawk Point to the south. Some of the towns along the bay's north shore include Turkey Point and Port Dover. Long Point is north across the lake from Erie, Pennsylvania. Settlers from Europe began arriving in this area in 1790. After the American Revolution, many Loyalists began to settle here but after 1796, land was given to anyone, capable of developing it; the first lighthouse was built in 1830. In the 19th century, a powerful storm cut an opening through the middle of Long Point. A lighthouse was built alongside the channel, the first of several on the point; the opening became known as "The Old Cut".
The cut has since closed along the lakeshore, but boaters continue to use the northern portion to access the bay and cottages. During the mid-19th century some of local residents saw an opportunity to make easy money by "blackbirding." Blackbirders erected fake lighthouses during times of low visibility. Ships trying to enter the old cut would run aground; when the crew abandoned ship the blackbirders would loot the ship of cargo and other valuables. With law enforcement based in London, these blackbirders would store their loot on the many hiding spots that Long Point offered. Abigail Becker on several occasions in the 19th century waded into stormy waters to save crew members of boats that had run aground. Long Point has caused many shipwrecks, with many of the wrecks located right off the tip of the point. More than 400 ships have sunk in an area called "The Lake Erie Quadrangle". Sport hunting was important after the Long Point Company purchased the Point in 1866 to facilitate this pursuit.
Long Point Provincial Park was created in May 1921. In economic terms, Norfolk County is one of the most diversified agricultural economies in Canada, with gross farm receipts of US$420 million, making it the fifth-largest agricultural region in Ontario. A wide range of field, oilseed, fruit and specialty crops are grown. Livestock production includes beef and dairy cattle and poultry; the population of Norfolk County in 2006 was 62,563, up 2.8% from 60,845 in 2001. Eco-tourism forms an important part of the local economy; the year-round population of Long Point is about 450 people, but the population increases in summer months when cottagers and campers visit. Long Point is popular destination for boating, fishing, waterfowl-hunting and canoeing, attracting between 100,000 and 300,000 visitors each year. A large portion of Long Point is owned by the Long Point Company, a private organization that does not allow the public onto its property; because of this, most homes and business are within the first few kilometres of the causeway that carries the road between Long Point and the mainland.
Long Point is the location of an Ontario provincial park, Long Point Provincial Park, a popular destination for day visitors and campers. North of the peninsula lie four islands classified as Lake Erie Islands: Ryerson's, Snow, "Millionaire's Island", a collection of cabins located southwest of Ryerson's Island. Long Point Bay is an important stopover point for migratory waterfowl. Much of the area is still owned by The Long Point Company and public is not allowed to enter; the Long Point National Wildlife Area was designated as a World Biosphere Reserve by UNESCO in 1986. Long Point is sand-spit formation in the Great Lakes region, it is the largest erosion deposit formation in the Great Lakes, created by water-borne sediments swept eastward and deposited in part along an underwater glacial moraine. Habitats on and surrounding Long Point include woodlands, sand dunes and bluffs, ponds, meadows and lakeshore; the complex is the largest biophysical formation of its kind in the Laurentian Great Lakes of North America.
In 1982, Long Point National Wildlife Area was recognized as a wetland of international significance under the Ramsar Convention. In 1986 Long Point Biosphere Reserve has been designated as a World Biosphere Reserve by UNESCO and as a globally significant Important Bird Area by Bird Life International; the Ontario Ministry of Natural Resources classifies Long Point as a Macrosite, an area that contains numerous ecological or geological significant zones, such as Areas of Natural and Scientific Interest. Inner Long Point Bay covers 78 km2 between the spit and Lake Erie’s north shore; the Inner Bay is a diverse sport fishery and continentally important staging area for migratory waterfowl. Adjacent to the coastal reserve is a distinctive terrestrial area of temperate ‘Carolinian’ broadleaf forests, conifer plantations, oak savannas and diverse agro-ecosystems; the reserve and surrounding region hold 1,384 species of plants. The region is an important location for bird migration in spring and autumn, including half of the eastern North American tundra swan population.
The region is a major staging area for many breeds of waterfowl. "Long Point itself is one of the most important wetland complexes for migrating waterfowl in southern Canada, is reported to receive the highest waterfowl use of any area on the Great Lakes. Up to 30,000 Tundra Swans pass th
Kaliningrad Oblast referred to as the Kaliningrad Region in English, or Kaliningrad, is a federal subject of the Russian Federation, located on the coast of the Baltic Sea. As an oblast, its constitutional status is equal to each of the other 84 federal subjects, its administrative center is the city of Kaliningrad known as Königsberg. It is the only Baltic port in the Russian Federation. According to the 2010 census, it had a population of 941,873; the oblast is an exclave, bordered by Poland to the south and Lithuania to the east and north, so residents may only travel visa-free to the rest of Russia via sea or air. The territory was the northern part of East Prussia, with the southern part now being Poland's Warmian-Masurian Voivodeship. With the defeat of Nazi Germany in 1945, the territory was annexed by the Soviet Union. Following the post-war migration and Flight and expulsion of Germans, the territory was populated with citizens from the Soviet Union. Today no ethnic Germans remain. Early in the 21st century, the hitherto fledgling economy of Kaliningrad Oblast became one of the best performing economies in Russia.
This was helped by a low manufacturing tax rate related to its "Special Economic Zone" status. As of 2006, one in three televisions manufactured in Russia came from Kaliningrad; the territory's population was one of the few in Russia, expected to show strong growth after the collapse of the USSR. During the Middle Ages, the territory of what is now Kaliningrad Oblast was inhabited by tribes of Old Prussians in the western part and by Lithuanians in the eastern part; the tribes were divided by the rivers Alna. The Teutonic Knights established a monastic state. On the foundations of a destroyed Prussian settlement known as Tvanksta, the Order founded the city of Königsberg. Germans assimilated the indigenous Old Prussians; the Lithuanian-inhabited areas became known as Lithuania Minor. Speakers of the old Baltic languages became extinct around the 17th century, having been assimilated and Germanised. In 1525, Grand Master Albert of Brandenburg secularized the Prussian branch of the Teutonic Order and established himself as the sovereign of the Duchy of Prussia.
The duchy was nominally a fief of the Polish crown. It merged with the Margraviate of Brandenburg. Königsberg was the duchy's capital from 1525 until 1701; as the centre of Prussia moved westward, the position of the capital became too peripheral and Berlin became the new Prussian capital city. During the Seven Years' War it was occupied by the Russian Empire; the region was reorganized into the Province of East Prussia within the Kingdom of Prussia in 1773. The territory of the Kaliningrad Oblast lies in the northern part of East Prussia; the annexation of the territory, while on a temporary basis, was approved by the "Big Three" allied leaders of World War II in the Potsdam Agreement in 1945. Three years after the annexation by the Russian Soviet Federative Socialist Republic, the remaining two-thirds of East Prussia was annexed by Poland and is today organised into the Warmian-Masurian province. In 1824, shortly before its merger with West Prussia, the population of East Prussia was 1,080,000 people.
Of that number, according to Karl Andree, Germans were more than half, while 280,000 were ethnically Polish and 200,000 were ethnically Lithuanian. As of 1819 there were 20,000 strong ethnic Curonian and Latvian minorities as well as 2,400 Jews, according to Georg Hassel. Similar numbers are given with a breakdown by county. However, the majority of East Prussian Polish and Lithuanian inhabitants were Lutherans, not Roman Catholics like their ethnic kinsmen across the border in the Russian Empire. Only in Southern Warmia Catholic Poles - so called Warmiaks - comprised the majority of population, numbering 26,067 people in county Allenstein in 1837. Another minority in 19th century East Prussia, were ethnically Russian Old Believers known as Philipponnen - their main town was Eckersdorf. In year 1817, East Prussia had 796,204 Evangelical Christians, 120,123 Roman Catholics, 864 Mennonites and 2,389 Jews. East Prussia was an important centre of German culture. Many important figures, such as Immanuel Kant and E. T. A. Hoffmann, came from this region.
Despite being damaged during World War II and thereafter, the cities of the oblast still contain examples of German architecture. The Jugendstil style showcases cultural importance of the area. By the early 20th century, Lithuanians formed a majority only in rural parts of the north-eastern corner of East Prussia. A similar fate befell the Latvian-speaking Kursenieki who had settled the coast of East Prussia between Gdańsk and Klaipėda; the rest of the area, with the exception of the Slavic Masurians in southern Prussia, was overwhelmingly German-speaking. The Memel Territory part of north-eastern East Prussia as well as Lithuania Minor, was annexed by Lithuania in 1923. In 1938, Nazi Germany radically altered about a third of the place names of this area, replacing Old Prussian and Lithuanian names with newly invented German names. Slavic and Jewish populations under Nazi Germany were classified as subhuman and were the target of a campaign of genocide by the German state, with the eventual goal of their
Longshore drift from longshore current is a geological process that consists of the transportation of sediments along a coast parallel to the shoreline, dependent on oblique incoming wind direction. Oblique incoming wind squeezes water along the coast, so generates a water current which moves parallel to the coast. Longshore drift is the sediment moved by the longshore current; this current and sediment movement occur within the surf zone. Beach sand is moved on such oblique wind days, due to the swash and backwash of water on the beach. Breaking surf sends water up the beach at an oblique angle and gravity drains the water straight downslope perpendicular to the shoreline, thus beach sand can move downbeach in a zig zag fashion many tens of meters per day. This process is called "beach drift" but some workers regard it as part of "longshore drift" because of the overall movement of sand parallel to the coast. Longshore drift affects numerous sediment sizes as it works in different ways depending on the sediment.
Sand is affected by the oscillatory force of breaking waves, the motion of sediment due to the impact of breaking waves and bed shear from long-shore current. Because shingle beaches are much steeper than sandy ones, plunging breakers are more to form, causing the majority of long shore transport to occur in the swash zone, due to a lack of an extended surf zone. There are numerous calculations that take into consideration the factors that produce longshore drift; these formulations are: Bijker formula Bijker formula The Engelund and Hansen formula The Ackers and White formula The Bailard and Inman formula The Van Rijn formula The Watanabe formula These formulas all provide a different view into the processes that generate longshore drift. The most common factors taken into consideration in these formulas are: Suspended and bed load transport Waves e.g. breaking and non-breaking The shear exerted by waves or the flow associated with waves. Longshore drift plays a large role in the evolution of a shoreline, as if there is a slight change of sediment supply, wind direction, or any other coastal influence longshore drift can change affecting the formation and evolution of a beach system or profile.
These changes do not occur due to one factor within the coastal system, in fact there are numerous alterations that can occur within the coastal system that may affect the distribution and impact of longshore drift. Some of these are: e.g. erosion, backshore changes and emergence of headlands. Change in hydrodynamic forces, e.g. change in wave diffraction in headland and offshore bank environments. Change deltas on drift. Alterations of the sediment budget, e.g. switch of shorelines from drift to swash alignment, exhaustion of sediment sources. The intervention of humans, e.g. cliff protection, detached breakwaters. By the Hydrogenic order of the atoms from water, Nathan James Heenan has proved in 1924 that water itself without force of wind can destroy or add deposition to the sea beds, we can find this out by the equation: H2o x force of water - Amount of H2 The sediment budget takes into consideration sediment sources and sinks within a system; this sediment can come from any source with examples of sources and sinks consisting of: Rivers Lagoons Eroding land sources Artificial sources e.g. nourishment Artificial sinks e.g. mining/extraction Offshore transport Deposition of sediment on shore Gullies through the landThis sediment enters the coastal system and is transported by longshore drift.
A good example of the sediment budget and longshore drift working together in the coastal system is inlet ebb-tidal shoals, which store sand, transported by long-shore transport. As well as storing sand these systems may transfer or by pass sand into other beach systems, therefore inlet ebb-tidal systems provide a good sources and sinks for the sediment budget. Sediment deposition throughout a shoreline profile conforms to the null point hypothesis. Long shore occurs in a 90 to 80 degree backwash so it would be presented as a right angle with the wave line; this section consists of features of longshore drift that occur on a coast where long-shore drift occurs uninterrupted by man-made structures. Spits are formed when longshore drift travels past a point where the dominant drift direction and shoreline do not veer in the same direction; as well as dominant drift direction, spits are affected by the strength of wave driven current, wave angle and the height of incoming waves. Spits are landforms that have two important features, with the first feature being the region at the up-drift end or proximal end.
The proximal end is attached to land and may form a slight “barrier” between the sea and an estuary or lagoon. The second important spit feature is the down-drift end or distal end, detached from land and in some cases, may take a complex hook-shape or curve, due to the influence of varying wave directions; as an example, the New Brighton spit in Canterbury, New Zealand, was created by longshore drift of sediment from the Waimakariri River to the north. This spit system is in equilibrium but undergoes alternate phases of deposition and erosion. Barrier systems are attached to the land at both the proximal and distal end and are generally
Sediment transport is the movement of solid particles due to a combination of gravity acting on the sediment, and/or the movement of the fluid in which the sediment is entrained. Sediment transport occurs in natural systems where the particles are mud, or clay. Sediment transport due to fluid motion occurs in rivers, lakes and other bodies of water due to currents and tides. Transport is caused by glaciers as they flow, on terrestrial surfaces under the influence of wind. Sediment transport due only to gravity can occur on sloping surfaces in general, including hillslopes, scarps and the continental shelf—continental slope boundary. Sediment transport is important in the fields of sedimentary geology, civil engineering and environmental engineering. Knowledge of sediment transport is most used to determine whether erosion or deposition will occur, the magnitude of this erosion or deposition, the time and distance over which it will occur. Aeolian or eolian is the term for sediment transport by wind.
This process results in the formation of ripples and sand dunes. The size of the transported sediment is fine sand and smaller, because air is a fluid with low density and viscosity, can therefore not exert much shear on its bed. Bedforms are generated by aeolian sediment transport in the terrestrial near-surface environment. Ripples and dunes form as a natural self-organizing response to sediment transport. Aeolian sediment transport is common on beaches and in the arid regions of the world, because it is in these environments that vegetation does not prevent the presence and motion of fields of sand. Wind-blown fine-grained dust is capable of entering the upper atmosphere and moving across the globe. Dust from the Sahara deposits on the Canary Islands and islands in the Caribbean, dust from the Gobi desert has deposited on the western United States; this sediment is important to the soil ecology of several islands. Deposits of fine-grained wind-blown glacial sediment are called loess. In geology, physical geography, sediment transport, fluvial processes relate to flowing water in natural systems.
This encompasses rivers, periglacial flows, flash floods and glacial lake outburst floods. Sediment moved by water can be larger than sediment moved by air because water has both a higher density and viscosity. In typical rivers the largest carried sediment is of sand and gravel size, but larger floods can carry cobbles and boulders. Fluvial sediment transport can result in the formation of ripples and dunes, in fractal-shaped patterns of erosion, in complex patterns of natural river systems, in the development of floodplains. Coastal sediment transport takes place in near-shore environments due to the motions of waves and currents. At the mouths of rivers, coastal sediment and fluvial sediment transport processes mesh to create river deltas. Coastal sediment transport results in the formation of characteristic coastal landforms such as beaches, barrier islands, capes; as glaciers move over their beds, they move material of all sizes. Glaciers can carry the largest sediment, areas of glacial deposition contain a large number of glacial erratics, many of which are several metres in diameter.
Glaciers pulverize rock into "glacial flour", so fine that it is carried away by winds to create loess deposits thousands of kilometres afield. Sediment entrained in glaciers moves along the glacial flowlines, causing it to appear at the surface in the ablation zone. In hillslope sediment transport, a variety of processes move regolith downslope; these include: Soil creep Tree throw Movement of soil by burrowing animals Slumping and landsliding of the hillslopeThese processes combine to give the hillslope a profile that looks like a solution to the diffusion equation, where the diffusivity is a parameter that relates to the ease of sediment transport on the particular hillslope. For this reason, the tops of hills have a parabolic concave-up profile, which grades into a convex-up profile around valleys; as hillslopes steepen, they become more prone to episodic landslides and other mass wasting events. Therefore, hillslope processes are better described by a nonlinear diffusion equation in which classic diffusion dominates for shallow slopes and erosion rates go to infinity as the hillslope reaches a critical angle of repose.
Large masses of material are moved in debris flows, hyperconcentrated mixtures of mud, clasts that range up to boulder-size, water. Debris washes; because they transport sediment as a granular mixture, their transport mechanisms and capacities scale differently from those of fluvial systems. Sediment transport is applied to solve many environmental and geological problems. Measuring or quantifying sediment transport or erosion is therefore important for coastal engineering. Several sediment erosion devices have been designed in order to quantitfy sediment erosion. One such device referred to as the BEAST has been calibrated in order to quantify rates of sediment erosion. Movement of sediment is important in providing habitat for fish and other organisms in rivers. Therefore, managers of regulated rivers, which are sediment-starved due to dams, are advised to stage short floods to refresh the bed material and rebuild bars
Spurn is a narrow sand tidal island located off the tip of the coast of the East Riding of Yorkshire, England that reaches into the North Sea and forms the north bank of the mouth of the Humber Estuary. Prior to a severe storm in February 2017, which damaged part of the sandbank, Spurn was a spit with a semi-permanent connection to the mainland. A storm in 2013 made the road down to the end of Spurn impassable to vehicles at high tide; the island is over 3 miles long half the width of the estuary at that point, as little as 50 yards wide in places. The southernmost tip is known as Spurn Head or Spurn Point and is the home to an RNLI lifeboat station and two disused lighthouses, it forms part of the civil parish of Easington. Spurn Head covers 450 acres of foreshore, it has been owned since 1960 by the Yorkshire Wildlife Trust and is a designated national nature reserve, heritage coast and is part of the Humber Flats and Coast Special Protection Area. Spurn Head was known to classical authors, such as Ptolemy as Ocelum Promontorium.
In the Middle Ages, Spurn Head was home to the port of Ravenspurn, where Henry of Bolingbroke landed in 1399 on his return to dethrone Richard II. It was where Sir Martin De La See led the local resistance against Edward IV's landing on 14 March 1471, as he was returning from his six months' exile in the Netherlands. An earlier village, closer to the point of Spurn Head, was Ravenser Odd. Along with many other villages on the Holderness coast and Ravenser Odd were lost to the encroachments of the sea, as Spurn Head, due to erosion and deposition of its sand, migrated westward; the lifeboat station at Spurn Head was built in 1810. Owing to the remote location, houses for the lifeboat crew and their families were added a few years later; the station is now one of only a few in the UK which has full-time paid staff. By the 1870s a room in the high lighthouse was being used as a chapel for the small residential community on Spurn Head, serving'the keepers, coast-guardsmen and fishermen who live at the Point'.
During the First World War two coastal artillery 9.2-inch batteries were added at either end of Spurn Head, with 4-inch and 4.7-inch quick firing guns in between. The emplacements can be seen, the northern ones are interesting as coastal erosion has toppled them onto the beach, revealing the size of the concrete foundations well; as well as a road, the peninsula used to have a railway, parts of which can still be seen. Unusual'sail bogies' were used as well as more conventional light railway equipment. Following a tidal surge in December 2013 the roadway is unsafe, access to Spurn Point is on foot only, with a warning not to attempt this when exceptionally high tides are due. Plans to build a new visitor centre for the reserve were unveiled in September 2014 by Yorkshire Wildlife Trust. Planning consent for the initial plans was refused by East Riding of Yorkshire Council in July 2016 but revised plans were approved in January 2017; these plans face local opposition because of the perceived feeling of commercialisation of the reserve by YWT, with plans to build extensive car park facilities, no longer free.
The new visitor centre was opened on 20 March 2018. On or around 20 February 2017 the Spurn Head spit was damaged in a storm, destroying the tarmac road to Spurn Head, afterwards flooded across at each high tide. Since this storm, Spurn has now become a tidal island, as the narrowest part of the sandbank connection to the mainland is flooded with each high tide; the spit is made up from sand and shingle and boulder clay eroded from the Holderness coastline washed down the coastline from Flamborough Head. Material is washed down the coast by longshore drift and accumulates to form the long, narrow embankment in the sheltered waters inside the mouth of the Humber Estuary, it is maintained by plants Marram grass. Waves carry material along the peninsula to the tip; when the sea cuts across it permanently, everything beyond the breach is swept away, only to reform as a new spit pointing further south. This cycle of destruction and reconstruction occurs every 250 years. More Dr. John Pethick of Hull University put forward a different theory to explain the formation of Spurn Head.
He suggests that the spit head has been a permanent feature since the end of the last ice age, having developed on an underwater glacial moraine. As the ice sheets melted, sea level rose and longshore drift caused a spit to form between this and other islands along the moraine. Under normal circumstances, the sea washes over the neck of the spit taking sand from the seaward side and redepositing it on the landward side. Over time, the whole spit, length intact, slips back – with the spit-head remaining on its glacial foundation; this process has now been affected by the protection of the spit put in place during the Victorian era. This protection halted the wash-over process and resulted in the spit being more exposed due to the rest of the coast moving back 110 yards since the'protection' was constructed; the now crumbling defences will not be replaced and the spit will continue to move westwards at a rate of 2.2 yards per year, keeping pace with the coastal erosion further north. The second of the Six Studies in English Folk Song composed in 1926 by Ralph Vaughan Williams, the Andante sostenuto in E flat "