A thunderstorm known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Weak thunderstorms are sometimes called thundershowers. Thunderstorms occur in a type of cloud known as a cumulonimbus, they are accompanied by strong winds, produce heavy rain and sometimes snow, sleet, or hail, but some thunderstorms produce little precipitation or no precipitation at all. Thunderstorms may become a rainband, known as a squall line. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, tornadoes; some of the most persistent severe thunderstorms, known as supercells, rotate as do cyclones. While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction. Thunderstorms result from the rapid upward movement of moist air, sometimes along a front.
As the warm, moist air moves upward, it cools and forms a cumulonimbus cloud that can reach heights of over 20 kilometres. As the rising air reaches its dew point temperature, water vapor condenses into water droplets or ice, reducing pressure locally within the thunderstorm cell. Any precipitation falls the long distance through the clouds towards the Earth's surface; as the droplets fall, they become larger. The falling droplets create a downdraft as it pulls cold air with it, this cold air spreads out at the Earth's surface causing strong winds that are associated with thunderstorms. Thunderstorms can form and develop in any geographic location but most within the mid-latitude, where warm, moist air from tropical latitudes collides with cooler air from polar latitudes. Thunderstorms are responsible for the formation of many severe weather phenomena. Thunderstorms, the phenomena that occur along with them, pose great hazards. Damage that results from thunderstorms is inflicted by downburst winds, large hailstones, flash flooding caused by heavy precipitation.
Stronger thunderstorm cells are capable of producing waterspouts. There are four types of thunderstorms: single-cell, multi-cell cluster, multi-cell lines and supercells. Supercell thunderstorms are the most severe. Mesoscale convective systems formed by favorable vertical wind shear within the tropics and subtropics can be responsible for the development of hurricanes. Dry thunderstorms, with no precipitation, can cause the outbreak of wildfires from the heat generated from the cloud-to-ground lightning that accompanies them. Several means are used to study thunderstorms: weather radar, weather stations, video photography. Past civilizations held various myths concerning thunderstorms and their development as late as the 18th century. Beyond the Earth's atmosphere, thunderstorms have been observed on the planets of Jupiter, Saturn and Venus. Warm air has a lower density than cool air, so warmer air rises upwards and cooler air will settle at the bottom. Clouds form as warmer air, carrying moisture, rises within cooler air.
The moist air rises, and, as it does so, it cools and some of the water vapor in that rising air condenses. When the moisture condenses, it releases energy known as latent heat of condensation, which allows the rising packet of air to cool less than the cooler surrounding air continuing the cloud's ascension. If enough instability is present in the atmosphere, this process will continue long enough for cumulonimbus clouds to form and produce lightning and thunder. Meteorological indices such as convective available potential energy and the lifted index can be used to assist in determining potential upward vertical development of clouds. Thunderstorms require three conditions to form: Moisture An unstable airmass A lifting force All thunderstorms, regardless of type, go through three stages: the developing stage, the mature stage, the dissipation stage; the average thunderstorm has a 24 km diameter. Depending on the conditions present in the atmosphere, each of these three stages take an average of 30 minutes.
The first stage of a thunderstorm is developing stage. During this stage, masses of moisture are lifted upwards into the atmosphere; the trigger for this lift can be solar illumination, where the heating of the ground produces thermals, or where two winds converge forcing air upwards, or where winds blow over terrain of increasing elevation. The moisture carried upward cools into liquid drops of water due to lower temperatures at high altitude, which appear as cumulus clouds; as the water vapor condenses into liquid, latent heat is released, which warms the air, causing it to become less dense than the surrounding, drier air. The air tends to rise in an updraft through the process of convection; this process creates a low-pressure zone beneath the forming thunderstorm. In a typical thunderstorm 500 million kilograms of water vapor are lifted into the Earth's atmosphere. In the mature stage of a thunderstorm, the warmed air continues to rise until it reaches an area of warmer air and can rise no farther.
This'cap' is the tropopause. The air is instead forced to spread out; the resulting cloud is called cumulonimbus incus. The water droplets coalesce into heavier droplets and freeze to become ice particles; as these fall, they melt to become rain. If the updraft
Aeroparque Jorge Newbery
Jorge Newbery Airfield is an international airport located in Palermo neighbourhood, 2 km northeast of downtown Buenos Aires, Argentina. The airport covers an area of 138 hectares and is operated by Aeropuertos Argentina 2000 S. A, it is located in the Palermo ward, along the Río de la Plata, serves as the main hub for domestic flights. Since march of 2019 serves just international flights to Uruguay; the airport was proposed by Mayor Carlos Noël in 1925. A number of feasibility studies and zoning disputes followed. In 1938, plans were submitted for an island airport connected via causeway to Avenida General Paz. A former wetland reclaimed in 1916 from the Río de la Plata and closer to downtown was selected instead, the facility, designed by Aeronatics Secretariat engineer Víctor Acuña in 1945, was inaugurated in 1947 as Aeroparque 17 de Octubre. Served by a 1,000 m runway, it began operations in January 1948 as the main hub for domestic flights from Buenos Aires as well as flights to Uruguay, its first terminal was completed in 1951, by which time the runway was extended to 1,550 m.
The airport was renamed following the 1955 coup against President Juan Perón in honor of the pioneer of Argentine aviation, Jorge Newbery, was re-inaugurated in 1960 following work that expanded its main runway to 2,070 m and added a new terminal. The Argentine Air Force had a small base built near the eastern end of the airport in 1965. A new terminal for national air carrier Aerolíneas Argentinas was inaugurated in 1981, expanding total terminal area to 30,000 m2. Plans to merge Newbery with Ezeiza International Airport in a new facility located on an artificial island were revived in 1996 by a commission headed by Congressman Álvaro Alsogaray, though these plans were dropped, its operations, like those of all the nation's public airports, were privatized in 1998 and transferred to Aeropuertos Argentina 2000. The runway was further extended by 180 m in 2007, work began in 2009 to create greater distance between the nearby Rafael Obligado Coast Highway and the eastern end of the runway. Routes were added in March 2010 to destinations in Brazil and Paraguay.
Work began in 2011 on Terminals III and IV, totaling 35,000 m2. These terminals were inaugurated in March 2014 doubling the airport's passenger capacity. However, a recent increase in the number of airlines and flights operating at the airport has brought it to the limit of its capacity. Thus, the government decided to move all international flights to Ezeiza Airport from 2019. See source Wikidata query. On 11 January 1957, LADE Vickers Viking T-11 crashed on take-off. All 35 occupants perished. On 30 June 1961, Transcontinental S. A. C-46 Commando LV-FTO crashed on landing approach. Of 35 occupants, 24 died. On 17 December 1969, Austral Líneas Aéreas C-46 Commando LV-GEB lost engine 1 due to fuel exhaustion shortly after takeoff; the plane made a crash landing in a small sport field. Both of the crew members survived without injury. On 11 May 1975, Vickers Viscount CX-AQO of PLUNA was damaged beyond economic repair when it departed the runway. On 7 May 1981, Austral Líneas Aéreas Flight 901, a BAC 1-11, crashed on approach after a flight from Tucumán.
All 31 passengers and crew were killed. On 24 February 1999, Aerolineas Argentinas MD-88 LV-VBY was destroyed by hangar fire. On 31 August 1999, LAPA Flight 3142, a Boeing 737-200, crashed shortly after takeoff due to pilot error. 63 of the 100 passengers and crew were killed. Two people on the ground were killed, raising the death toll to 65. Museo Nacional de Aeronáutica de Argentina List of airports in Argentina Transport in Argentina Media related to Aeroparque Jorge Newbery at Wikimedia Commons Aeropuertos Argentina 2000 Accident history for AEP at Aviation Safety Network Aeronautical chart for SABE at SkyVector Current weather for SABE at NOAA/NWS
Juan de Garay
Juan de Garay was a Spanish conquistador. Garay's birthplace is disputed; some say it was in the Castile city of Junta de Villalba de Losa, while others argue he was born in the area of Orduña. There's no birth certification whatsoever, though Juan De Garay regarded himself as somebody from Biscay, he served in the Viceroyalty of Peru. He was governor of Asunción and founded a number of cities in present-day Argentina, many near the Paraná River area, including the second foundation of Buenos Aires, in 1580. In 1543 he sailed to Peru with his uncle Pedro de Zárate in Viceroy Blasco Núñez Vela's first expedition. In 1561 he took part in the foundation of Santa Cruz de la Sierra. In 1568 he moved to Asunción; the governor of Asunción sent him in April 1573, with a company of eighty men, on an expedition to the Paraná River, during which he founded the city of Santa Fe de la Vera Cruz. In 1576 he was appointed governor of Asunción; as governor, he attempted to avoid bloodshed by bringing civilization to the natives.
To achieve these goals, he established local governments. In 1580, having attained the rank of Capitan General of the Viceroyalty, he re-founded the city on the banks of the Río de la Plata, first established by Pedro de Mendoza in 1536 under the name of Nuestra Señora del Buen Ayre, but was destroyed by the natives. Garay founded Buenos Aires a second time on June 11 in the year 1580, he landed on the riverbank in the location of Plaza de Mayo, calling the city Ciudad de la Trinidad and its port Santa Maria de Buenos Ayres. Buenos Aires would become the main city in its most important port, he went on an expedition in search for the legendary City of the Caesars. Juan de Garay died near the Río de la Plata, while travelling from Buenos Aires to Santa Fe on March 20, 1583, his group of 40 men, a Franciscan priest and a few women entered an unknown lagoon and decided to spend the night on the banks of the Carcarañá River, near the ancient Sancti Spíritus Fort; the group was ambushed by Querandíes natives who killed Garay, the priest, a woman, twelve of the soldiers.
He was made King. Garay had a daughter, Jerónima de Contreras, who married Hernando Arias de Saavedra, the governor of Rio de la Plata. In the oldest part of the town of Garay in Biscay is located a palace-baserri named Garatikua and built by Juan de Garay. In the 19th century, it was called "Garay-Goitia". According to García Carraffa, the Garay's coat of arms indicates an origin from the noble Garay Family of Tudela mentioned in the thirteenth century. Juan de Garay as a Biscayan had the title of knight, a title the "Fueros" granted to all the Vizcayans; the family had a certain economic and cultural level, it should be kept in mind that his uncle was appointed Judge and "Alcalde Mayor" of Segovia and his cousin attended the University of Salamanca. Juan joined the family of his uncle, made by Pedro Ortiz de Zárate, his wife Catalina Uribe and Salazar and his cousins: Pedro Ortiz de Zárate, Ana Salazar and the youngest of the brothers Francisco Uribe; the three children bear different surnames, only the firstborn retains that of the father, while the others adopt the mother's surname.
He had a family relationship with Juan Ortiz de Zárate, third "Adelantado" of the Rio de la Plata. On his doubtful birth place Biography Fundación Vasco Argentina Biografía
Radical Civic Union
The Radical Civic Union is a centrist social-liberal political party in Argentina. The party has been ideologically heterogeneous; the UCR is a member of the Socialist International. Founded in 1891 by radical liberals, it is the oldest political party active in Argentina after the Liberal Party of Corrientes. For many years the party was either in opposition to Peronist governments or illegal during military rule; the UCR's main support comes from the middle class. Throughout its history the party has stood for free elections, supremacy of civilians over the military and liberal democratic values. During the 1970s and 1980s it was perceived as a strong advocate for human rights. By May 2014, the UCR had 14 Senators; the party was a breakaway from the Civic Union, led by Bartolomé Mitre and Leandro Alem. The term'radical' in the party's name referred to its demand for universal male suffrage, considered radical at the time, when Argentina was ruled by an exclusive oligarchy and government power was allocated behind closed doors.
The party unsuccessfully led an attempt to force the early departure of President Miguel Juárez Celman in the Revolution of the Park. A compromise was reached with Juárez Celman's government. Hardliners who opposed this agreement founded the current UCR, led by Alem's nephew, the young and charismatic Hipólito Yrigoyen. In 1893 and 1905 the party led unsuccessful revolutions to overthrow the government. With the introduction of free and confidential voting in elections based on universal adult male suffrage in 1912 the Party managed to win the general elections of 1916, when Hipólito Yrigoyen became president; as well as backing more popular participation, UCR's platform included promises to tackle the country's social problems and eradicate poverty. Yrigoyen's presidency however turned out to be rather dictatorial; the Radical Civic Union remained in power during the next 14 years: Yrigoyen was succeeded by Marcelo T. de Alvear in 1922 and again by himself in 1928. The first coup in Argentina's modern history occurred on September 6, 1930 and ousted an aging Yrigoyen amid an economic crisis resulting from the United States' Great Depression.
From 1930 to 1958 the Radical Civic Union was confined to be the main opposition party, either to the Conservatives and the military during the 1930s and the early 1940s or to the Peronists during the late 1940s and early 1950s. It was only in 1958 that a faction of the party allied with banned Peronists came back to power, led by Arturo Frondizi; the growing tolerance of Frondizi towards his Peronist allies provoked unrest in the army, which ousted the president in March 1962. After a brief military government, presidential elections took place in 1963 with the Peronist Party banned; the outcome saw the candidate of the People's Radical Civic Union Arturo Illia coming first but with only 25% of the votes. Although Argentina experienced during Illia's presidency one of the most successful periods of history in terms of economic performance, the president was ousted by the army in June 1966. Illia's peaceful and ordered style of governing — sometimes considered too "slow" and "boring" - was being criticized at the time.
During the 1970s Peronist government, the Radical Civic Union was the second-most supported party, but this didn't grant the party the role of being the political opposition. In fact, the Peronist government's most important criticisms came from the same Peronist Party; the UCR's leader in those times, Ricardo Balbín, saluted Peron's coffin with the famous sentence "This old adversary salutes a great friend", thus marking the end of the Peronist-radical rivalry that had marked the pace of the Argentine political scene until then. The growing fight between left-wing and right-wing Peronists took the country into chaos and many UCR members were targeted by both factions; the subsequent coup in 1976 ended Peronist rule. During the military regime many members of the UCR were "disappeared", as were members of other parties. Between 1983 and 1989 its leader, Raúl Ricardo Alfonsín, was the first democratically elected president after the military dictatorship headed by generals such as Jorge Videla, Leopoldo Galtieri and Reynaldo Bignone.
Alfonsín was succeeded by Carlos Saúl Menem of the Peronist Justicialist Party. In 1997 the UCR participated in elections in coalition with Front for a Country in Solidarity, itself an alliance of many smaller parties; this strategy brought Fernando de la Rúa to the presidency in the 1999 elections. During major riots triggered by economic reforms implemented by the UCR government, President de la Rúa resigned and fled the country to prevent further turmoil. After three consecutive acting presidents assumed and resigned their duties in the following weeks, Eduardo Duhalde of the PJ took office until new elections could be held. After the 2001 legislative elections it became the second-largest party in the federal Chamber of Deputies, winning 71 of 257 seats, it campaigned in an alliance with the smaller, more leftist FREPASO. The party has subsequently declined markedly and its candidate for President in 2003 gained just 2.34% of the vote, beaten by three Peronis
Buenos Aires Province
Buenos Aires is the largest and most populous Argentinian province. It takes the name from the city of Buenos Aires, which used to be part of the province and the provincial capital until it was federalized in 1880. Since in spite of bearing the same name, the province does not include the national capital city proper, though it does include all other localities of the Greater Buenos Aires metropolitan area surrounding it; the current capital of the province is the city of La Plata, founded in 1882. The province is the only within the whole Argentina to be divided into partidos and furtherly into localidades, borders the provinces of Entre Ríos to the northeast. Uruguay is just near the Atlantic Ocean to the east; the entire province is part of the Pampas geographical region. The province has a population of 39 % of Argentina's total population. Nearly 10 million people live in Greater Buenos Aires; the area of the province, 307,571 km2, makes it the largest in Argentina with around 11% of the country's total area.
The inhabitants of the province before the 16th century advent of Spanish colonisation were aboriginal peoples such as the Charrúas and the Querandíes. Their culture was lost over the next 350 years, they were subjected to Eurasian plagues from. The survivors joined other tribes or have been absorbed by Argentina's European ethnic majority. Pedro de Mendoza founded Santa María del Buen Ayre in 1536. Though the first contact with the aboriginals was peaceful, it soon became hostile; the city was evacuated in 1541. Juan de Garay re-founded the settlement in 1580 as Santísima Trinidad y Puerto Santa María de los Buenos Aires. Amidst ongoing conflict with the aboriginals, the cattle farms extended from Buenos Aires, whose port was always the centre of the economy of the territory. Following the creation of the Viceroyalty of the Río de la Plata at the end of the 18th century, the export of meat and their derivatives through the port of Buenos Aires was the basis of the economic development of the region.
Jesuits unsuccessfully tried to peacefully assimilate the aboriginals into the European culture brought by the Spanish conquistadores. A certain balance was found at the end of the 18th century, when the Salado River became the limit between both civilizations, despite frequent malones; the end to this situation came in 1879 with the Conquest of the Desert in which the aboriginals were completely exterminated. After the independence from Spain in 1816, the city and province of Buenos Aires became the focus of an intermittent Argentine Civil War with other provinces. A Federal Pact secured by Governor Juan Manuel de Rosas in 1831 led to the establishment of the Argentine Confederation and to his gaining the sum of public power, which provided a tenuous unity. Ongoing disputes regarding the influence of Buenos Aires, between Federalists and Unitarians, over the Port of Buenos Aires fueled periodic hostilities; the province was declared independent on September 1852, as the State of Buenos Aires.
Concessions gained in the 1859 Pact of San José de Flores and a victory at the Battle of Pavón led to its reincorporation into the Argentine Republic on December 17, 1861. Intermittent conflicts with the nation did not cease until 1880, when the city of Buenos Aires was formally federalized and, administratively separated from the province. La Plata was founded in 1882 by Governor Dardo Rocha for the purpose of becoming the provincial capital; the equivalent of a billion dollars of British investment and pro-development and immigration policies pursued at the national level subsequently spurred dramatic economic growth. Driven by European immigration and improved health, the province's population, like Argentina's, nearly doubled to one million by 1895 and doubled again by 1914. Rail lines connected nearly every town and hamlet in the province by 1914; this era of accelerated development was cut short by the Wall Street Crash of 1929, which caused a sharp drop in commodity prices and led to a halt in the flow of investment funds between nations.
The new Concordance and Perón governments funded ambitious lending and public works programs, visible in Buenos Aires Province through the panoply of levees, power plants, water works, paved roads, municipal buildings, schools and massive regional hospitals. The province's population, after 1930, began to grow disproportionately in the suburban areas of Buenos Aires; these suburbs had grown to include 4 million out of the province's total 7 million people in 1960. Much of the area these new suburbs were developed on consisted of wetlands and were prone to flooding. To address this, Governor Oscar Alende initiated the province's most important flood-control project to date, the Roggero Reservoir. Completed a decade in 1971, the reservoir and associated electric and water-treatment facilities encouraged still more, more orderly, development of the Greater Buenos Aires region, which today includes around 10 million people, it did not address worsening pollution resulting from the area's industrial growth, which had made itself evident since aroun
A heat wave is a period of excessively hot weather, which may be accompanied by high humidity in oceanic climate countries. While definitions vary, a heat wave is measured relative to the usual weather in the area and relative to normal temperatures for the season. Temperatures that people from a hotter climate consider normal can be termed a heat wave in a cooler area if they are outside the normal climate pattern for that area; the term is applied both to hot weather variations and to extraordinary spells of hot which may occur only once a century. Severe heat waves have caused catastrophic crop failures, thousands of deaths from hyperthermia, widespread power outages due to increased use of air conditioning. A heat wave is considered extreme weather, a danger because heat and sunlight may overheat the human body. Heat waves can be detected using forecasting instruments so that a warning call can be issued. A definition based on Frich et al.'s Heat Wave Duration Index is that a heat wave occurs when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C, the normal period being 1961–1990.
A formal, peer-reviewed definition from the Glossary of Meteorology is: A period of abnormally and uncomfortably hot and humid weather. To be a heat wave such a period should last at least one day, but conventionally it lasts from several days to several weeks. In 1900, A. T. Burrows more rigidly defined a “hot wave” as a spell of three or more days on each of which the maximum shade temperature reaches or exceeds 90 °F. More realistically, the comfort criteria for any one region are dependent upon the normal conditions of that area; the World Meteorological Organization, defines a heat wave as 5 or more consecutive days of prolonged heat in which the daily maximum temperature is higher than the average maximum temperature by 9 °F or more. However, some nations have come up with their own criteria to define a heat wave. In the Netherlands, a heat wave is defined as a period of at least 5 consecutive days in which the maximum temperature in De Bilt exceeds 25 °C, provided that on at least 3 days in this period the maximum temperature in De Bilt exceeds 30 °C.
This definition of a heat wave is used in Belgium and Luxembourg. In Denmark, a national heat wave is defined as a period of at least 3 consecutive days of which period the average maximum temperature across more than fifty percent of the country exceeds 28 °C – the Danish Meteorological Institute further defines a "warmth wave" when the same criteria are met for a 25 °C temperature, while in Sweden, a heat wave is defined as at least 5 days in a row with a daily high exceeding 25 °C. In the United States, definitions vary by region. In the Northeast, a heat wave is defined as three consecutive days where the temperature reaches or exceeds 90 °F, but not always as this ties in with humidity levels to determine a heat index threshold; the same does not apply to drier climates. A heat storm is a Californian term for an extended heat wave. Heat storms occur when the temperature reaches 100 °F for three or more consecutive days over a wide area; the National Weather Service issues heat advisories and excessive heat warnings when unusual periods of hot weather are expected.
In Adelaide, South Australia, a heat wave is defined as five consecutive days at or above 35 °C, or three consecutive days at or over 40 °C. The Australian Bureau of Meteorology defines a heat wave as "three days or more of maximum and minimum temperatures that are unusual for the location"; until the introduction of this new Pilot Heatwave Forecast there was no national definition that described heatwave or measures of heatwave severity. In the United Kingdom, the Met Office operates a Heat Health Watch system which places each Local Authority region into one of four levels. Heatwave conditions are defined by the maximum daytime temperature and minimum nighttime temperature rising above the threshold for a particular region; the length of time spent above that threshold determines the particular level. Level 1 is normal summer conditions. Level 2 is reached when there is a 60% or higher risk that the temperature will be above the threshold levels for two days and the intervening night. Level 3 is triggered when the temperature has been above the threshold for the preceding day and night, there is a 90% or higher chance that it will stay above the threshold in the following day.
Level 4 is triggered. Each of the first three levels is associated with a particular state of readiness and response by the social and health services, Level 4 is associated with more widespread response. A more general indicator that allows comparing heat waves in different regions of the World, characterized by different climates, has been developed; this was used to estimate heat waves occurrence at the global scale from 1901 to 2010, finding a substantial and sharp increase in the amount of affected areas in the last two decades. Heat waves form when high pressure aloft strengthens and remains over a region for several days up to several weeks; this is common in summer as the jet stream'follows the sun'. On the equator side of the jet stream, in the upper layers of the atmosphere, is the high pressure area. Summertime weather patterns are slower to change than in winter; as a result, this upper level high pressure moves slowly
The Paraná River is a river in south Central South America, running through Brazil and Argentina for some 4,880 kilometres. It is second in length only to the Amazon River among South American rivers; the name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language and means "like the sea". It merges first with the Paraguay River and farther downstream with the Uruguay River to form the Río de la Plata and empties into the Atlantic Ocean; the first European to go up the Paraná River was the Venetian explorer Sebastian Cabot, in 1526, while working for Spain. The course is formed at the confluence of the Rio Grande rivers in southern Brazil. From the confluence the river flows in a southwestern direction for about 619 km before encountering the city of Saltos del Guaira, Paraguay; this was once the location of the Guaíra Falls (Sete Quedas waterfalls, where the Paraná fell over a series of seven cascades. This natural feature was said to rival the world-famous Iguazu Falls to the south.
The falls were flooded, however, by the construction of the Itaipu Dam, which began operating in 1984. For the next 200 km the Paraná flows southward and forms a natural boundary between Paraguay and Brazil until the confluence with the Iguazu River. Shortly upstream from this confluence, the river is dammed by the Itaipu Dam, the second largest hydroelectric power plant in the world, creating a massive, shallow reservoir behind it. After merging with the Iguazu, the Paraná becomes the natural border between Paraguay and Argentina. Overlooking the Paraná River from Encarnación, across the river, is downtown Posadas, Argentina; the river continues its general southward course for about 468 km before making a gradual turn to the west for another 820 km, encounters the Paraguay River, the largest tributary along the course of the river. Before this confluence the river passes through a second major hydroelectric project, the Yaciretá Dam, a joint project between Paraguay and Argentina; the massive reservoir formed by the project has been the source of a number of problems for people living along the river, most notably the poorer merchants and residents in the low-lying areas of Encarnación, a major city on the southern border of Paraguay.
River levels rose upon completion of the dam, flooding out large sections of the city's lower areas. From the confluence with the Paraguay River, the Paraná again turns to the south for another 820 km through Argentina, making a slow turn back to the east near the city of Rosario for the final stretch of less than 500 km before merging with the Uruguay River to form the Río de la Plata; this flows into the Atlantic Ocean. During the part of its course downstream from the city of Diamante, Entre Ríos, it splits into several arms and it forms the Paraná Delta. Together with its tributaries, the Rio Paraná forms a massive drainage basin that encompasses much of the southcentral part of South America including all of Paraguay, much of southern Brazil, northern Argentina, the southeastern part of Bolivia. If the Uruguay River is counted as a tributary to the Paraná, this watershed extends to cover most of Uruguay as well; the volume of water flowing into the Atlantic Ocean through the Río de la Plata equals the volume at the Mississippi River delta.
This watershed contains a number of large cities, including São Paulo, Buenos Aires, Asunción, Brasília, La Plata. The Paraná and its tributaries provide a source of income and of daily sustenance for fishermen who live along its banks; some of the species of fish are commercially important, they are exploited for heavy internal consumption or for export. The Parana River delta ranks as one of the world's greatest bird-watching destinations. Much of the length of the Paraná is navigable, the river serves as an important waterway linking inland cities in Argentina and Paraguay with the ocean, providing deepwater ports in some of these cities; the construction of enormous hydroelectric dams along the river's length has blocked its use as a shipping corridor to cities further upstream, but the economic impact of those dams offsets this. The Yacyretá Dam and the Itaipu Dam on the Paraguay border have made the small undeveloped nation of Paraguay the world's largest exporter of hydroelectric power.
Due to its use for oceangoing ships, measurements of the water tables extend back to 1904. The data correlates with the solar cycle; the course of the Paraná is crossed by the following bridges, beginning upstream: Tributaries of the Río de la Plata Paraná River steamers Information and a map of the Paraná's watershed "Paraná". New International Encyclopedia. 1905