Köppen climate classification
The Köppen climate classification is one of the most used climate classification systems. It was first published by the Russian climatologist Wladimir Köppen in 1884, with several modifications by Köppen, notably in 1918 and 1936; the climatologist Rudolf Geiger introduced some changes to the classification system, thus sometimes called the Köppen–Geiger climate classification system. The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns; the five main groups are A, B, C, D, E. Each group and subgroup is represented by a letter. All climates are assigned a main group. All climates except for those in the E group are assigned a seasonal precipitation subgroup. For example, Af indicates a tropical rainforest climate; the system assigns a temperature subgroup for all groups other than those in the A group, indicated by the third letter for climates in B, C, D, the second letter for climates in E.
For example, Cfb indicates an oceanic climate with warm summers as indicated by the ending b. Climates are classified based on specific criteria unique to each climate type. Köppen designed the system based on his experience as a botanist, so the main climate groups are based on the different variety of vegetation that grows in climates belonging to each group. In addition to identifying climates, the system can be used to analyze ecosystem conditions and identify the main types of vegetation within climates. Due to its link with the plant life of a region, the system is useful in predicting future changes in plant life within a region; the Köppen climate classification system has been further modified, within the Trewartha climate classification system in the middle 1960s. The Trewartha system sought to create a more refined middle latitude climate zone, one of the criticisms of the Köppen system; the Köppen climate classification scheme divides climates into five main climate groups: A, B, C, D, E.
The second letter indicates the seasonal precipitation type, while the third letter indicates the level of heat. Summers are defined as the 6 month period, warmer either from April–September and/or October–March while winter is the 6 month period, cooler. Group A: Tropical climates This type of climate has every month of the year with an average temperature of 18 °C or higher, with significant precipitation. Af = Tropical rainforest climate. Am = Tropical monsoon climate. Aw or As = Tropical wet and dry or savanna climate. Group B: Dry climates This type of climate is defined by little precipitation. Multiply the average annual temperature in Celsius by 20 add 280 if 70% or more of the total precipitation is in the spring and summer months, or 140 if 30%–70% of the total precipitation is received during the spring and summer, or 0 if less than 30% of the total precipitation is received during the spring and summer. If the annual precipitation is less than 50% of this threshold, the classification is BW.
A third letter can be included to indicate temperature. H signified low-latitude climate while k signified middle-latitude climate, but the more common practice today in the United States, is to use h to mean the coldest month has an average temperature above 0 °C, with k denoting that at least one month's averages below 0 °C; the n is used to denote a climate characterized by frequent fog. BWh = Hot desert climate BWk = Cold desert climate BSh = Hot semi-arid climate BSk = Cold semi-arid climateGroup C: Temperate climates This type of climate has the coldest month averaging between 0 °C and 18 °C and at least one month averaging above 10 °C. Cfa = Humid subtropical climate. No significant precipitation difference between seasons. No dry months in the summer. Cfb = Temperate oceanic climate. No significant precipitation difference between seasons. Cfc = Subpolar oceanic climate. No significant precipitation difference between seasons. Cwa = Monsoon-influenced humid subtropical climate.
The Bulgaria–Romania border is the state border between Bulgaria and Romania. For most of its length, the border follows the course of the lower Danube River up until the town of Silistra, where the river continues north into the Romanian territory. East of that point, the land border passes through the historical region of Dobruja, dividing it into Northern Dobruja in Romania and Southern Dobruja in Bulgaria; the Bulgaria–Romania border is an internal border of the European Union. However, as of 2019 neither country is part of the Schengen Area; as a result, border controls are conducted between the two countries, albeit jointly. Vidin–Calafat: road, railway Oryahovo-Bechet: ferry Nikopol-Turnu Măgurele: ferry Svishtov-Zimnicea: ferry Ruse–Giurgiu: road, railway Silistra–Ostrov: road Kaynardzha–Lipnița: road Kardam–Negru Vodă: road, railway Durankulak–Vama Veche: road Bulgaria–Romania relations
Humid subtropical climate
A humid subtropical climate is a zone of climate characterized by hot and humid summers, mild winters. These climates lie on the southeast side of all continents between latitudes 25° and 40° and are located poleward from adjacent tropical climates. While many subtropical climates tend to be located at or near coastal locations, in some cases they extend inland, most notably in China and the United States, where they exhibit more pronounced seasonal variations and sharper contrasts between summer and winter, as part of a gradient between the more tropical climates of the southern coasts of these countries and the more continental climates of China and the United States’ northern and central regions. Under the Köppen climate classification and Cwa climates are either described as humid subtropical climates or mild temperate climates; this climate features mean temperatures in the coldest month between 0 °C or −3 °C and 18 °C and mean temperatures in the warmest month 22 °C or higher. However, while some climatologists have opted to describe this climate type as a "humid subtropical climate", Köppen himself never used this term.
The humid subtropical climate classification was created under the Trewartha Climate classification. The Trewartha system was a 1966 update of the Köppen climate classification, sought to redefine middle latitude climates into smaller zones. Under the Trewartha climate classification, climates are termed humid subtropical when they have monthly mean air temperatures higher than 10 °C for eight or more months a year and at least one month with mean temperature below 18 °C. Under the Trewartha system, humid subtropical climates occupy the southernmost portions of the temperate zone from 23.5 to 35.0 north and south latitude. Rainfall shows a summer peak where monsoons are well developed, as in Southeast Asia and South Asia. Other areas have a more uniform or varying rainfall cycles, but lack any predictably dry summer months. Most summer rainfall occurs during thunderstorms that build up due to the intense surface heating and strong subtropical sun angle. Weak tropical lows that move in from adjacent warm tropical oceans, as well as infrequent tropical storms contribute to summer seasonal rainfall peaks.
Winter rainfall is associated with large storms in the westerlies that have fronts that reach down into subtropical latitudes. However, many subtropical climates such as southeast Asia or Florida have dry winters, with frequent brush fires and water shortages. In Africa, humid subtropical climates are found in the southern hemisphere of the continent; the Cwa climate is found over a large portion of the interior of the Middle and Eastern African regions. This area includes central Angola, northeastern Zimbabwe, the Niassa and Tete provinces of Mozambique, the southern Congo provinces, southwest Tanzania, the majority of Malawi, Zambia; some lower portions of the Ethiopian Highlands have this climate. The climate is found in the narrow coastal sections of southern and eastern South Africa in KwaZulu-Natal and the Eastern Cape provinces. South Africa's version of this climate features heavy oceanic influences resulting in milder temperatures; this is evident in its winters when temperatures do not drop as low as in many other regions within the humid subtropical category.
In East and Southeast Asia, this climate type is found in the southeastern quarter of mainland China from Hong Kong north to Nanjing, the northern half of Taiwan, northern Myanmar, northern Vietnam, north through southern and central Japan, the extreme southern tip of South Korea around Busan. Cities near the equatorward boundary of this zone include Hong Kong and Taipei; the influence of the strong Siberian anticyclone in East Asia brings colder winter temperatures than the humid subtropical zones in North America, South America, Australia. The 0 °C isotherm reaches as far south as the valleys of the Yellow and Wei latitude 34° N. At Hainan Island and in Taiwan, the climate transitions from subtropical into tropical. In most of this region, the winter monsoon is well developed, as such eastern Asian humid subtropical zones have a strong winter dry season and heavy summer rainfall. Only in inland areas below the Yangtze River and coastal areas between the Huai River and the beginning of the coast of Guangdong is there sufficient winter rainfall to produce a Cfa climate.
Drought can be severe and catastrophic to agriculture in the Cwa zone. The only area where winter precipitation equals or exceeds the summer rain is on the "San-in", or western, coast of Japan, which during winter is on the windward side of the westerlies; the winter precipitation in these regions is produced by low-pressure systems off the east coast that develop in the onshore flow from the Siberian high. Summer rainfall comes from frequent typhoons. Annual rainfall is over 1,000 millimetres, in areas below the Himalayas can be much higher still. Humid subtropical climates can be found in South Asia along the Ganges River. However
Roman Tomb (Silistra)
The Roman Tomb of Silistra is an Ancient Roman burial tomb in the town of Silistra in northeastern Bulgaria. Dating to the mid-4th century AD, the Roman Tomb is the best-preserved architectural monument of the Ancient Roman city of Durostorum; the tomb is considered "one of the most investigated and most discussed monuments of the late antique art in Bulgaria" and the Balkans, owing in large part to the quality and extent of its interior frescoes. Though the influence of Christianity had reached Silistra by the time, the Roman Tomb is an example of pagan art commissioned by a pagan owner. Thus, it is considered that it predates Theodosius I's persecution of Roman paganism, its construction likely preceded the Gothic invasion of Durostorum of 376–378, which caused great turmoil in the city. The invasion may have caused the master's family depicted in the tomb to flee the city, explaining the lack of burials in the tomb. In any case, the tomb must be stylistically ascribed to the 4th century and to Theodosius I's reign.
The Roman Tomb was coincidentally discovered in 1942 in the southern outskirts of Silistra, a major town in Southern Dobruja on the banks of the Lower Danube. Silistra had only been transferred by Romania back to Bulgaria as part of the 1940 Treaty of Craiova. Since 1984, the Roman Tomb of Silistra has been on UNESCO's Tentative List of World Heritage Sites; the stone tomb features a single burial chamber and measures 3.30 by 2.60 metres. It has a west-east orientation, with the entrance on the east wall and a semi-cylindrical brick vault, it is located amidst the ruins of a necropolis from Late Antiquity which included other similar structures. Ceramic plates, rectangular in shape and painted using the fresco-secco technique, cover the entirety of its floor. In contrast to most other known Roman tombs from the period in the Balkans, the entire interior is covered by multi-coloured mural paintings; the northern and eastern walls feature a procession of servants, whereas the frescoes of the western wall, directly opposite the entrances, depict the master and his wife.
A frieze running along the walls of the tomb contains 11 panels featuring the portraits of male and female slaves bringing various gifts and garments to the masters. The procession runs from either side of the central panel that portrays the masters, providing for a symmetrical composition; the tomb's decoration includes hunting scenes, candlesticks and animals, including peacocks and pigeons. Overall, the decoration's remarkable level of preservation and the quality of the mural paintings makes the tomb a "unique example of art and life" in the outer regions of the Roman Empire during the turbulent 4th century; the Roman Tomb of Silistra is situated at the intersection of the Sedmi Septemvri and Boyka Voyvoda Streets in the town. As of 2016, it can only be toured after a prior reservation at the Regional Historical Museum of Silistra. Atanasov, Georgi. "Late antique tomb in Durostorum‐Silistra and its master". Revista Pontica. Constanţa: National Museum of History and Archaeology. 40. ISSN 1013-4247.
Retrieved 23 January 2016
Provinces of Bulgaria
The provinces of Bulgaria are the first level administrative subdivisions of the country. Since 1999, Bulgaria has been divided into 28 provinces which correspond to the 28 districts, that existed before 1987; the provinces are further subdivided into 265 municipalities. Sofia – the capital city of Bulgaria and the largest settlement in the country, is the administrative centre of both Sofia Province and Sofia City Province; the capital is included in Sofia Capital Municipality, the sole municipality comprising Sofia City province. The provinces do not have official names – they are not named but only described as "oblast with administrative centre " - together with a list of the constituting municipalities. In Bulgaria they are called " Oblast"; the Bulgarian term "област" is preferably translated into English as "province", in order to avoid disambiguation and distinguish from the former unit called "окръг" and the term "регион". At any rate, "district" and "region" are sometimes still used to name these contemporary 28 units.
"region": "28 regions / région / oblast" – in ISO 3166-2 Newsletter II-3 "district": "The territory of the South Central Region encompasses five districts – Pazardzhik, Smolyan and Kyrdzhali." – in a website of the European Commission. In 1987, the then-existing 28 districts were transformed into 9 large units, which survived until 1999; the 9 large provinces are listed along with the pre-1987 districts comprising them. On 1 January 1999, the old districts were restored. Administrative divisions below the province level: List of cities and towns in Bulgaria List of villages in Bulgaria Municipalities of Bulgaria The constituencies of Bulgaria, which are based on the provinces ISO 3166-2:BG List of Bulgarian provinces by GDP Liste des gouverneurs des provinces bulgares
Flavius Aetius, dux et patricius called Aetius or Aëtius, was a Roman general of the closing period of the Western Roman Empire. He was an able military commander and the most influential man in the Western Roman Empire for two decades, he managed policy in regard to the attacks of barbarian federates settled throughout the Western Roman Empire. Notably, he mustered a large Roman and allied army to stop the Huns in the Battle of the Catalaunian Plains, ending the devastating Hunnic invasion of Attila in 451, he has been called "the last of the Romans". Edward Gibbon refers to him as "the man universally celebrated as the terror of Barbarians and the support of the Republic" for his alleged victory at the Catalaunian Plains. Aetius was born at Durostorum in Moesia Secunda, around 391, his father, Flavius Gaudentius, was a Roman general and described as a native of the Roman province of Scythia, although some have interpreted this as a topos and used to describe a Gothic origin. Aetius' mother, whose name is unknown, was a wealthy aristocratic woman of Italian ancestry.
Before 425 Aetius married the daughter of Carpilio, who gave him a son named Carpilio. He married Pelagia, widow of Bonifacius, from whom he had a son, Gaudentius, it is possible that he had a daughter, whose husband, avenged Aetius' death by killing emperor Valentinian III. As a boy, Aetius was at the service of the imperial court, enrolled in the military unit of the Protectores Domestici and elevated to the position of tribunus praetorianus partis militaris, setting him up for future political eligibility. Between 405 and 408 he was kept as hostage at the court of king of the Visigoths. In 408 Alaric asked to keep Aetius as a hostage, but was refused, as Aetius was sent to the court of Uldin, king of the Huns, where he would stay throughout much of the reign of Charaton, Uldin's successor. According to some early historians, Aetius's upbringing amongst militaristic peoples gave him a martial vigour not common in Roman generals of the time. In 423 the Western Emperor Honorius died; the most influential man in the West, chose as his successor Joannes, a high-ranking officer.
Joannes was not part of the Theodosian dynasty and he did not receive the recognition of the eastern court. The Eastern Emperor Theodosius II organised a military expedition westward, led by Ardaburius and his son Aspar, to put his cousin, the young Valentinian III, on the western throne. Aetius entered the service of the usurper as cura palatii and was sent by Joannes to ask the Huns for assistance. Joannes lacked a strong army and fortified himself in his capital, where he was killed in the summer of 425. Shortly afterwards, Aetius returned to Italy with a large force of Huns to find that power in the west was now in the hands of Valentinian III and his mother Galla Placidia. After fighting against Aspar's army, Aetius managed to compromise with Galla Placidia, he sent back his army of Huns and in return obtained the rank of comes et magister militum per Gallias, the commander in chief of the Roman army in Gaul. In 426, Aetius took command of the field army. At that time Arelate, an important city in Narbonensis near the mouth of the Rhone, was under siege from the Visigoths, led by their king Theodoric I.
Aetius defeated Theodoric, lifted the siege of Arelate, drove the Visigoths back to their holdings in Aquitania. In 428 he fought the Salian Franks, defeating their king Chlodio and recovering some territory they had occupied along the Rhine. In 429 he was elevated to the rank of magister militum. In 430 the Visigoths were defeated by Aetius. In May 430, Aetius and the Army accused Felix of plotting against him and had him, his wife, a deacon killed. Once Felix was dead, Aetius was the highest ranking amongst the magistri militiae if he had not yet been granted the title of patricius or the senior command. During late 430s and 431 Aetius was in Raetia and Noricum, defeating the Bacaudae in Augusta Vindelicorum, re-establishing Roman rule on the Danube frontier, campaigning against the Juthungi. In 431 he returned to Gaul, where he received Hydatius, bishop of Aquae Flaviae, who complained about the attacks of the Suebes. Aetius defeated the Franks, recapturing Tournacum and Cambriacum, he sent Hydatius back to the Suebes in Hispania.
While Aetius was campaigning in Gaul, there was an ongoing power struggle among Aetius, Felix and the emperor Valentinian's mother and regent Galla Placidia. In 427 while Bonifacius was away as governor of Africa, Felix caused him to fall into disfavour with Placidia. Bonifacius was returned to favor by Placidia, but only after Felix had sent Sigisvult and two other armies against him when Aetius warned him of Felix's intentions. In 429, the Vandals crossed over to Africa. After the execution of Felix in 430, Aetius and Bonifacius remained as the empire's most influential generals, both vying for the favor of Placidia. In 432 Aetius held the consulate, but Bonifacius was recalled to Italy and received warmly by Placidia. Bonifacius was given the rank of patrician and made the senior comes et magister utriusque militiae, while Aetius was stripped of his military command. Aetius, believing his fall now imminent, marched against Bonifacius and fought him at the Battle of Rimini. Bonifacius won
Western Roman Empire
In historiography, the Western Roman Empire refers to the western provinces of the Roman Empire at any time during which they were administered by a separate independent Imperial court. The terms Western Roman Empire and Eastern Roman Empire are modern descriptions that describe political entities that were de facto independent; the Western Roman Empire collapsed in 476, the Western imperial court was formally dissolved in 480. The Eastern imperial court survived until 1453. Though the Empire had seen periods with more than one Emperor ruling jointly before, the view that it was impossible for a single emperor to govern the entire Empire was institutionalised to reforms to Roman law by emperor Diocletian following the disastrous civil wars and disintegrations of the Crisis of the Third Century, he introduced the system of the tetrarchy in 286, with two separate senior emperors titled Augustus, one in the East and one in the West, each with an appointed Caesar. Though the tetrarchic system would collapse in a matter of years, the East–West administrative division would endure in one form or another over the coming centuries.
As such, the Western Roman Empire would exist intermittently in several periods between the 3rd and 5th centuries. Some emperors, such as Constantine I and Theodosius I, governed as the sole Augustus across the Roman Empire. On the death of Theodosius I in 395, he divided the empire between his two sons, with Honorius as his successor in the West, governing from Mediolanum, Arcadius as his successor in the East, governing from Constantinople. In 476, after the Battle of Ravenna, the Roman Army in the West suffered defeat at the hands of Odoacer and his Germanic foederati. Odoacer became the first King of Italy. In 480, following the assassination of the previous Western emperor Julius Nepos, the Eastern emperor Zeno dissolved the Western court and proclaimed himself the sole emperor of the Roman Empire; the date of 476 was popularized by the 18th century British historian Edward Gibbon as a demarcating event for the end of the Western Empire and is sometimes used to mark the transition from Antiquity to the Middle Ages.
Odoacer's Italy, other barbarian kingdoms, would maintain a pretence of Roman continuity through the continued use of the old Roman administrative systems and nominal subservience to the Eastern Roman court. In the 6th century, emperor Justinian I re-imposed direct Imperial rule on large parts of the former Western Roman Empire, including the prosperous regions of North Africa, the ancient Roman heartland of Italy and parts of Hispania. Political instability in the Eastern heartlands, combined with foreign invasions and religious differences, made efforts to retain control of these territories difficult and they were lost for good. Though the Eastern Empire retained territories in the south of Italy until the eleventh century, the influence that the Empire had over Western Europe had diminished significantly; the papal coronation of the Frankish King Charlemagne as Roman Emperor in 800 marked a new imperial line that would evolve into the Holy Roman Empire, which presented a revival of the Imperial title in Western Europe but was in no meaningful sense an extension of Roman traditions or institutions.
The Great Schism of 1054 between the churches of Rome and Constantinople further diminished any authority the Emperor in Constantinople could hope to exert in the west. As the Roman Republic expanded, it reached a point where the central government in Rome could not rule the distant provinces. Communications and transportation were problematic given the vast extent of the Empire. News of invasion, natural disasters, or epidemic outbreak was carried by ship or mounted postal service requiring much time to reach Rome and for Rome's orders to be returned and acted upon. Therefore, provincial governors had de facto autonomy in the name of the Roman Republic. Governors had several duties, including the command of armies, handling the taxes of the province and serving as the province's chief judges. Prior to the establishment of the Empire, the territories of the Roman Republic had been divided in 43 BC among the members of the Second Triumvirate: Mark Antony and Marcus Aemilius Lepidus. Antony received the provinces in the East: Achaea and Epirus, Bithynia and Asia, Syria and Cyrenaica.
These lands had been conquered by Alexander the Great. The whole region the major cities, had been assimilated into Greek culture, Greek serving as the lingua franca. Octavian obtained the Roman provinces of the West: Italia, Gallia Belgica, Hispania; these lands included Greek and Carthaginian colonies in the coastal areas, though Celtic tribes such as Gauls and Celtiberians were culturally dominant. Lepidus received the minor province of Africa. Octavian soon took Africa while adding Sicilia to his holdings. Upon the defeat of Mark Antony, a victorious Octavian controlled a united Roman Em