Neva
The Neva is a river in northwestern Russia flowing from Lake Ladoga through the western part of Leningrad Oblast to the Neva Bay of the Gulf of Finland. Despite its modest length of, it is the fourth-largest river in Europe in terms of average discharge.
The Neva is the only river flowing from Lake Ladoga. It flows through the city of Saint Petersburg, the three smaller towns of Shlisselburg, Kirovsk and Otradnoye, and dozens of settlements. It is navigable throughout and is part of the Volga–Baltic Waterway and White Sea–Baltic Canal. It is the site of many major historical events, including the Battle of the Neva in 1240 which gave Alexander Nevsky his name, the founding of Saint Petersburg in 1703, and the Siege of Leningrad by the German army during World War II. The river played a vital role in trade between Byzantium and Scandinavia.
Etymology
The earliest people in recorded history known to have inhabited the area are the Finnic people. The word Neva is widespread in Finnic languages, having quite cognate meanings. In Finnish it means poor fen, in Karelian: watercourse and in Estonian : waterway.It has been postulated the name could derive from Indo-European adjective newā which means new – the river began its flow some time between 2000 BC and 1250 BC. However, the local place names with such influence coincide with Scandinavian traders and Slavs' first main settlement in the region, in the 8th century AD.
Description
History of the delta
In the Paleozoic, 300–400 million years ago, all the delta region was covered by a sea. Modern relief, eminences, were formed by glacial scouring. Its retreat formed the Littorina Sea, the level of which was higher than its successor the Baltic Sea. Then, the Tosna was flowing in the modern lower half of the Neva as today, into the Litorinal Sea. In the north of the Karelian Isthmus, the sea was united by a wide strait with Lake Ladoga. The Mga then flowed to the east, into Lake Ladoga, near the modern source of the Neva. Thus the Mga then was separate from the Tosna/lower-Neva basin.Near the modern Lake Ladoga, by glacial rebound land rose faster, and an endorheic lake briefly formed. This overspilled, eventually the whole Mga valley and thus broke into the western valley. The Ivanovo rapids of the modern Neva were created at the breakthrough. According to early books, the breakthrough may have been about 2000 BC, but according to more recent research, this happened at 1410–1250 BC, making the river rather young.
The valley is lined with glacial and post-glacial sediments and has changed little over 2,500 years. The delta was formed at that time, technically a pseudodelta, as not from accumulation of river material but by scouring past sediments.
Topography and hydrography
The Neva flows out of Lake Ladoga near Shlisselburg, flows through Neva's lowlands and discharges into the Baltic Sea in the Gulf of Finland. It has a length of, and the shortest distance from the source to the mouth is. The river banks are low and steep, on average about and at the mouth. There are three sharp turns: the Ivanovskye rapids, at Nevsky Forest Park of the Ust-Slavyanka region, and near the Smolny Institute, below the mouth of the river Okhta. The river declines in elevation between source and mouth. At one point the river crosses a moraine ridge and forms the Ivanovskye rapids. There, at the beginning of the rapids, is the narrowest part of the river:. The average flow rate in the rapids is about. The average width along the river is. The widest places, at, are in the delta, near the gates of the marine trading port, at the end of the Ivanovskye rapids near the confluence of the river Tosna, and near the island Fabrinchny near the source. The average depth is ; the maximum of is reached above the Liteyny Bridge, and the minimum of is in Ivanovskye rapids.In the Neva basin, rainfall greatly exceeds evaporation; the latter accounts for only 37.7 percent of the water consumption from the Neva and the remaining 62.3 percent is water runoff. Since 1859, the largest volume of was observed in 1924 and the lowest in 1900 at. The average annual discharge is or on average. Due to the uniform water flow from Lake Ladoga to the Neva over the whole year, there are almost no floods and corresponding water rise in the spring. The Neva freezes throughout from early December to early April. The ice thickness is within Saint Petersburg and in other areas. Ice congestion may form in winter in the upper reaches of the river, this sometimes causes upstream floods. Of the total ice volume of Lake Ladoga,, less than 5 percent enters the Neva. The average summer water temperature is, and the swimming season lasts only about 1.5 months. The water is fresh, with medium turbidity; the average salinity is 61.3 mg/L and the calcium bicarbonate content is 7 mg/L.
Basin, tributaries and distributaries
The basin area of Neva is 5,000 km2, including the pools of Lake Ladoga and Onega. The basin contains 26,300 lakes and has a complex hydrological network of more than 48,300 rivers, however only 26 flow directly into Neva. The main tributaries are Mga, Tosna, Izhora, Slavyanka and Murzinka on the left, and Okhta and Chyornaya Rechka on the right side of Neva.The hydrological network had been altered by the development of Saint Petersburg through its entire history. When it was founded in 1703, the area was low and swampy and required construction of canals and ponds for drainage. The earth excavated during their construction was used to raise the city. At the end of the 19th century, the delta of Neva consisted of 48 rivers and canals and 101 islands. The most significant distributaries of the delta are listed in the table. Before construction of the Obvodny Canal, the left tributary of that area was the Volkovka; its part at the confluence is now called Monastyrka. The Ladoga Canal starts at the root of Neva and connects it along the southern coast of Lake Ladoga with the Volkhov.
Some canals of the delta were filled over time, so that only 42 islands remained by 1972, all within the city limits of St. Petersburg. The largest islands are Vasilyevsky at, Petrogradsky at, Krestovsky at, and Dekabristov at ; others include Zayachy, Yelagin and Kamenny Islands. At the source of the Neva, near Shlisselburg, there are the two small islands of Orekhovy and Fabrichny. Island Glavryba lies up the river, above the town of Otradnoye.
Flora and fauna
There is almost no aquatic vegetation in Neva. The river banks mostly consist of sand, podsol, gleysols, peat, and boggy peat soils. Several centuries ago, the whole territory of the Neva lowland was covered by pine and spruce mossy forests. They were gradually reduced by the fires and cutting for technical needs. Extensive damage was caused during World War II: in Saint Petersburg, the forests were reduced completely, and in the upper reaches down to 40 to 50 percent. Forest were replanted after the war with spruce, pine, cedar, Siberian larch, oak, Norway maple, elm, America, ash, apple tree, mountain ash and other species. The shrubs include barberry, lilac, jasmine, hazel, honeysuckle, hawthorn, rose hip, viburnum, juniper, elder, shadbush and many others.Nowadays, the upper regions of the river are dominated by birch and pine-birch grass-shrub forests and in the middle regions there are swampy pine forests.
In St. Petersburg, along the Neva, there are many gardens and parks, including the Summer Garden, Field of Mars, Rumyantsev, Smolny, Alexander Gardens, Garden of the Alexander Nevsky Lavra and many others.
Because of the rapid flow, cold water and lack of quiet pools and aquatic vegetation the diversity of fish species in Neva is small. Permanent residents include such undemanding to environment species as perch, ruffe and roaches. Many fish species are transitory, of which commercial value have smelt, vendace and partly salmon.
Floods
Floods in St. Petersburg are usually caused by the overflow of the delta of Neva and by surging water in the eastern part of Neva Bay. They are registered when the water rises above with respect to a gauge at the Mining Institute. More than 300 floods occurred after the city was founded in 1703. Three of them were catastrophic: on 7 November 1824, when water rose to ; on 23 September 1924 when it reached, and 10 September 1777 when it rose to. However, a much larger flood of was described in 1691.Besides flooding as a result of tidal waves, in 1903, 1921 and 1956 floods were caused by the melting of snow.
Ecological condition
The Federal Service for Hydrometeorology and Environmental Monitoring of Russia classifies the Neva as a "heavily polluted" river. The main pollutants include copper, zinc, manganese, nitrites and nitrogen. The dirtiest tributaries of the Neva are the Mga, Slavyanka, Ohta, and Chernaya. Hundreds of factories pour wastewater into the Neva within St. Petersburg, and petroleum is regularly transported along the river. The annual influx of pollutants is 80,000 tonnes, and the heaviest polluters are Power-and-heating Plant 2, "Plastpolymer" and "Obukhov State Plant". The biggest polluters in the Leningrad Oblast are the cities of Shlisselburg, Kirovsk and Otradnoye, as well as the Kirov thermal power station. More than 40 oil spills are registered on the river every year.In 2008, the Federal Service of St. Petersburg announced that no beach of the Neva was fit for swimming.
Cleaning of wastewater in Saint Petersburg started in 1979; by 1997, about 74% was purified. This rose to 85% in 2005, to 91.7% by 2008, and Feliks Karamzinov expected it to reach almost 100% by 2011 with the completion of the expansion of the main sewerage plant.
History
Before 1700
Many sites of ancient people, up to nine thousand years old, were found within the territory of the Neva basin. It is believed that around twelve thousand years BC, Finnic people moved to this area from the Ural Mountains.In the 8th and 9th centuries AD, the area was inhabited by the East Slavs who were mainly engaged in slash and burn agriculture, hunting and fishing. From the 8th to 13th centuries, Neva provided a waterway from Scandinavia to the Byzantine Empire. In the 9th century, the area belonged to Veliky Novgorod. The Neva was already mentioned in the Life of Alexander Nevsky. At that time, Veliky Novgorod was engaged in nearly constant wars with Sweden. A major battle occurred on 15 July 1240 at the confluence of the Izhora and Neva Rivers. The Russian army, led by the 20-year-old Prince Alexander Yaroslavich, aimed to stop the planned Swedish invasion. The Swedish army was defeated; the prince showed personal courage in combat and received the honorary name of "Nevsky".
As a result of the Russian defeat in the Ingrian War of 1610–17 and the concomitant Treaty of Stolbovo, the area of the Neva River became part of Swedish Ingria. Beginning in 1642, the capital of Ingria was Nyen, a city near the Nyenschantz fortress. Because of financial and religious oppression, much of the Orthodox population left the Neva region, emptying 60 percent of the villages by 1620. The abandoned areas became populated by people from the Karelian Isthmus and Savonia.