The monsoon season is the time of year when most of a region's average annual rainfall occurs. The season lasts at least a month; the term "green season" is sometimes used as a euphemism by tourist authorities. Areas with wet seasons are dispersed across portions of the subtropics. Under the Köppen climate classification, for tropical climates, a wet season month is defined as a month where average precipitation is 60 millimetres or more. In contrast to areas with savanna climates and monsoon regimes, Mediterranean climates have wet winters and dry summers. Dry and rainy months are characteristic of tropical seasonal forests: in contrast to tropical rainforests, which do not have dry or wet seasons, since their rainfall is distributed throughout the year; some areas with pronounced rainy seasons will see a break in rainfall mid-season, when the intertropical convergence zone or monsoon trough moves to higher latitudes in the middle of the warm season. When the wet season occurs during a warm season, or summer, precipitation falls during the late afternoon and early evening.
In the wet season, air quality improves, fresh water quality improves, vegetation grows leading to crop yields late in the season. Rivers overflow their banks, some animals retreat to higher ground. Soil nutrients erosion increases; the incidence of malaria increases in areas where the rainy season coincides with high temperatures in tropical areas. Some animals have survival strategies for the wet season; the previous dry season leads to food shortages in the wet season, as the crops have yet to mature. In areas where the heavy rainfall is associated with a wind shift, the wet season is known as the monsoon. Rainfall in the wet season is due to daytime heating which leads to diurnal thunderstorm activity within a pre-existing moist airmass, so the rain falls in late afternoon and early evening in savannah and monsoon regions. Further, much of the total rainfall each day occurs in the first minutes of the downpour, before the storms mature into their stratiform stage. Most places have only one wet season, but areas of the tropics can have two wet seasons, because the monsoon trough, or Intertropical Convergence Zone, can pass over locations in the tropics twice per year.
However, since rain forests have rainfall spread evenly through the year, they do not have a wet season. It is different for places with a Mediterranean climate. In the western United States, during the cold season from September–May, extratropical cyclones from the Pacific Ocean move inland into the region due to a southward migration of the jet stream during the cold season; this shift in the jet stream brings much of the annual precipitation to the region, sometimes brings heavy rain and strong low pressure systems. The peninsula of Italy has weather similar to the western United States in this regard. Areas with a savanna climate in Sub-Saharan Africa, such as Ghana, Burkina Faso, Eritrea and Botswana have a distinct rainy season. Within the savanna climate regime and South Texas have a rainy season. Monsoon regions include the Indian subcontinent, Southeast Asia, northern sections of Australia's North, Central America and southern Mexico, the Desert Southwest of the United States, southern Guyana, portions of northeast Brazil.
Northern Guyana has the other in early winter. In western Africa, there are two rainy seasons across southern sections, but only one across the north. Within the Mediterranean climate regime, the west coast of the United States and the Mediterranean coastline of Italy and Turkey experience a wet season in the winter months; the wet season in the Negev desert of Israel extends from October through May. At the boundary between the Mediterranean and monsoon climates lies the Sonoran desert, which receives the two rainy seasons associated with each climate regime; the wet season is known by many different local names throughout the world. For example, in Mexico it is known as "storm season". Different names are given to the various short "seasons" of the year by the Aboriginal tribes of Northern Australia: the wet season experienced there from December to March is called Gudjewg; the precise meaning of the word is disputed, although it is accepted to relate to the severe thunderstorms and abundant vegetation growth experienced at this time.
In tropical areas, when the monsoon arrives, high daytime high temperatures drop and overnight low temperatures increase, thus reducing diurnal temperature variation. During the wet season, a combination of heavy rainfall and, in some places such as Hong Kong, an onshore wind, improve air quality. In Brazil, the wet season is correlated with weaker trade winds off the ocean; the pH level of water becomes more balanced due to the charging of local aquifers during the wet season. Water softens, as the concentration of dissolved materials reduces during the rainy season. Erosion is increased during rainy periods. Arroyos that are dry at other times of the year fill with runoff, in some cases with water as deep as 10 feet. Leaching of soils during periods of heavy rainfall depletes nutrients; the higher runoff from land masses affects nearby ocean areas, which are more stratified, or less mixed, due to stronger surface currents forced by the heavy rainfall runoff. High rainfall can cause widespread flooding, which can lead to landslides and mudflows in mountainous areas.
Such floods cause rivers to submerge homes. The Ghaggar-Hakra River, which only flows during India's monsoon season, can flood and damage local
Okahandja is a city of 24,100 inhabitants in Otjozondjupa Region, central Namibia, the district capital of the Okahandja electoral constituency. It is known as the Garden Town of Namibia, it is located 70 km north of Windhoek on the B1 road. It was founded by two local groups, the Herero and the Nama. Okahandja means the place. A German pastor, Heinrich Schmelen, became the first European to visit the town in 1827. In 1844, two missionaries were permanently assigned to the town, Heinrich Kleinschmidt and Hugo Hahn. A church dates from this period. A military post was established at the initiative of Theodor Leutwein in 1894, it is this date, recognized as the town's founding. A number of important historic Namibian people are buried in Okahandja, among them Maharero, Jan Jonker Afrikaner, Hosea Kutako and Clemens Kapuuo. Okahandja's population is growing rapidly, it stood at just over 14,000 as measured by the 2001 Population and Housing Census, is estimated to have surpassed 24,000 in 2012. Von Bach Dam is situated outside of Okahandja.
It provides the majority of Windhoek's water. An open-air curio market attracts tourists, the town serves as the administrative centre for the Herero people. Okahandja Railway Station, situated on the Windhoek—Swakopmund line, was built in 1902 during Imperial Germany's colonial rule of German South West Africa. Today it belongs to the Trans-Namib railway network. In the 1870s Rhenish missionaries established the first school; the Augustineum School was reopened at Okahandja on 9 November 1905. Today Okahandja has two high schools. Namwater Vocational, situated outside the main town, is the only institute of higher education in Okahandja; the National Institute for Educational Development is today situated in Okahandja. NIED was created after independence as the institute from where a new national system of education was created, replacing the previous racist system of apartheid; the German school Regierungsschule Okahandja was in the city. Okahandja is governed by a municipal council. In the 2010 local authority election in Okahandja, SWAPO won with 62% of the vote.
Of the five other parties seeking votes in the election, Rally for Democracy and Progress received 13% of the vote, followed by the United Democratic Front, the United People's Movement, National Unity Democratic Organization and Democratic Turnhalle Alliance. The 2015 local authority election was again won by SWAPO which gained 2,572 votes. One seat each went to the UDF with 236 and 213 votes, respectively. In the 1970s, Okahandja Soccer Club had a competitive football team. In addition, local club Liverpool Okahandja were NFA-Cup winners in 1992 and Namibia Premier League champions in 2002. Vyf Rand
In geography, a confluence occurs where two or more flowing bodies of water join together to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river. Confluences are studied in a variety of sciences. Hydrology studies the characteristic flow patterns of confluences and how they give rise to patterns of erosion and scour pools; the water flows and their consequences are studied with mathematical models. Confluences are relevant to the distribution of living organisms as well; the United States Geological Survey gives an example: "chemical changes occur when a stream contaminated with acid mine drainage combines with a stream with near-neutral pH water. According to Lynch, "the color of each river is determined by many things: type and amount of vegetation in the watershed, geological properties, dissolved chemicals and biologic content – algae." Lynch notes that color differences can persist for miles downstream before they blend completely.
Hydrodynamic behaviour of flow in a confluence can be divided into six distinct features which are called confluence flow zones. These include Stagnation zone Flow deflection zone Flow separation zone / recirculation zone Maximum velocity zone Flow recovery zone Shear layers Since rivers serve as political boundaries, confluences sometimes demarcate three abutting political entities, such as nations, states, or provinces, forming a tripoint. Various examples are found in the list below. A number of major cities, such as Chongqing, St. Louis, Khartoum, arose at confluences. Within a city, a confluence forms a visually prominent point, so that confluences are sometimes chosen as the site of prominent public buildings or monuments, as in Koblenz and Winnipeg. Cities often build parks at confluences, sometimes as projects of municipal improvement, as at Portland and Pittsburgh. In other cases, a confluence is an industrial site, as in Mannheim. A confluence lies in the shared floodplain of the two rivers and nothing is built on it, for example at Manaus, described below.
One other way that confluences may be employed by humans is as a sacred place in a religion. Rogers suggests that for the ancient peoples of the Iron Age in northwest Europe, watery locations were sacred sources and confluences. Pre-Christian Slavic peoples chose confluences as the sites for fortified triangular temples, where they practiced human sacrifice and other sacred rites. In Hinduism, the confluence of two sacred rivers is a pilgrimage site for ritual bathing. In Pittsburgh, a number of adherents to Mayanism consider their city's confluence to be sacred. At Lokoja, the Benue River flows into the Niger. At Kazungula in Zambia, the Chobe River flows into the Zambezi; the confluence defines the tripoint of Zambia and Namibia. The land border between Botswana and Zimbabwe to the east reaches the Zambezi at this confluence, so there is a second tripoint only 150 meters downstream from the first. See Kazungula and Quadripoint, Gallery below for image; the Sudanese capital of Khartoum is located at the confluence of the White Nile and the Blue Nile, the beginning of the Nile.
82 km north of Basra in Iraq at the town of Al-Qurnah is the confluence of the rivers Tigris and Euphrates, forming the Shatt al-Arab. At Devprayag in India, the Ganges River originates at the confluence of the Bhagirathi and the Alaknanda. Near Allahabad, the Yamuna flows into the Ganges. In Hinduism, this is a pilgrimage site for ritual bathing. In Hindu belief the site is held to be a triple confluence, the third river being the metaphysical Sarasvati. Kuala Lumpur, the capital of Malaysia, is where the Gombak River flows into the Klang River at the site of the Jamek Mosque; the Kolam Biru, a pool with elaborate fountains, has been installed at the apex of the confluence. The Nam Khan River flows into the Mekong at Luang Prabang in Laos; the Jialing flows into the Yangtze at Chongqing in China. The confluence forms a focal point in the city, marked by Chaotianmen Square, built in 1998. In the Far East, the Amur forms the international boundary between Russia; the Ussuri, which demarcates the border, flows into the Amur at a point midway between Fuyuan in China and Khabarovsk in Russia.
The apex of the confluence is located in a rural area, part of China, where a commemorative park, Dongji Square, has been built.
Ephemerality is the concept of things being transitory, existing only briefly. The term ephemeral is used to describe objects found in nature, although it can describe a wide range of things, including human artifacts intentionally made to last for only a temporary period, in order to increase their perceived aesthetic value. With respect to unique performances, for example, it has been noted that "phemerality is a quality caused by the ebb and flow of the crowd's concentration on the performance and a reflection of the nostalgic character of specific performances"; because different people may value the passage of time differently, "the concept of ephemerality is a relative one". An ephemeral waterbody is a wetland, stream, pond or lake that only exists for a short period following precipitation or snowmelt, they are not the same as intermittent or seasonal waterbodies, which exist for longer periods, but not all year round. Examples of ephemeral streams are the Luni river in Rajasthan, Ugab River in Southern Africa, a number of small ephemeral watercourses that drain Talak in northern Niger.
Other notable ephemeral rivers include the Todd River and Sandover River in Central Australia as well as the Son River, Batha River and the Trabancos River. Any endorheic basin, or closed basin, that contains a playa or dry lake at its drainage lowpoint can become an ephemeral lake. Examples include Lake Carnegie in Western Australia, Lake Cowal in New South Wales, Mystic Lake and Rogers Lake in California, Sevier Lake in Utah; the driest and lowest place in North America, Death Valley, became flooded with a short-lived ephemeral lake in the spring of 2005. There are ephemeral islands such as Banua Wuhu and Home Reef; these islands appear when volcanic activity increases their height above sea level, but disappear over several years due to wave erosion. Bassas da India, on the other hand, is a near-sea level island. Many plants are adapted to an ephemeral lifestyle, in which they spend most of the year or longer as seeds before conditions are right for a brief period of growth and reproduction.
The spring ephemeral plant mouse-ear cress is a well-known example. Animals can be ephemeral, with the mayfly being examples; the placenta is considered an ephemeral organ present during pregnancy. Ephemeral can be used as an adjective to refer to a fast-deteriorating importance or temporary nature of an object to a person. Brands are notoriously ephemeral assets, magazine publishing was once much more ephemeral than it is today, as was television programming. A film made by a particular sponsor for a specific purpose other than as a work of art may be called an ephemeral film, because the film itself can continue to exist after the social or commercial context for its creation has disappeared. A number of art forms can be considered ephemeral because of their temporary nature. Early land art and all sand sculptures, ice sculptures and chalk drawings on footpaths are examples of ephemeral art. G. Augustine Lynas and Duthain Dealbh create ephemeral sculptures. In addition, temporary wall drawing artists such as Linn Meyers create ephemeral art within museums and galleries.
During the Baroque period, wealthy patrons would commission ephemeral creations from well-known artists of the time. These creations very expensive and time-consuming, were only used during one event before being dismantled or destroyed. One such work was the temporary volcano, created by Gianlorenzo Bernini for the Barberini family; the volcano, placed on the predecessor to the Spanish Steps, took three months to create and was destroyed in a firework display over the course of an hour. Ephemeroptera Christine Buci-Glucksmann, Esthetique De L'ephemere, Galilee, ISBN 2-7186-0622-3
Usakos is a town on the banks of river Khan, 140 kilometres north-east of Swakopmund in the Erongo Region of Namibia. It is located on the main road between the Walvis Bay and Johannesburg; the town owns 58 square kilometres of land. Surrounded by mountains, Usakos is quite picturesque. Certain spots around the town show the longest uninterrupted horizon in the world, it is the closest town to the Spitzkoppe referred to as the "Matterhorn of Namibia". The settlement was founded in the early 1900s as a watering station for locomotives. Herero chief Samuel Maharero sold the land to Europeans who resold it in 1903 to the Otavi Minen- und Eisenbahngesellschaft which operated an industrial railway line from Swakopmund to Tsumeb. OMEG established a railway station and a repair shop, used until the 1960s; when mining operations slowed down, Usakos' importance faded quickly. Today it is just a drive-through from the Namibian inland to the coast. Historic buildings and structures in Usakos are the Roman Catholic church, the now dilapidated railway station building, the old hotel.
Usakos is riddled with poverty and alcohol abuse, the current unemployment rate is around 60%. Unlike other Namibian towns, it has not seen substantial development since independence in 1990. Usakos Railway Station connects the town to the Namibian railway network. Usakos was downgraded from municipal to town status in 2010, it is now governed by a town council. In the 2010 local authority election, a total of 1,029 votes were cast in the city. SWAPO won with 47% of the vote. Of the three other parties seeking votes in the election, United Democratic Front received 31% of the vote, followed by RDP and COD. SWAPO won the 2015 local authority elections, gaining four seats. Two seats went to the UDF, the remaining one to the Democratic Turnhalle Alliance. Usakos is the hometown of the following prominent politicians: Michael Goreseb, member of the National Assembly of Namibia Theo-Ben Gurirab Speaker of the National Assembly Tsudao Gurirab, Member of Parliament from 1999 to 2009 Alpheus ǃNaruseb, Minister of Land and Resettlement Railway stations in Namibia
Swakopmund is a city on the coast of western Namibia, 352 km west of the Namibian capital Windhoek via the B2 main road. It is the capital of the Erongo administrative district; the town covers 196 square kilometres of land. The city is the fourth largest population centre in Namibia. Swakopmund is an example of German colonial architecture, it was founded in 1892 as the main harbour for German South West Africa, a small part of its population is still German-speaking today. Buildings in the city include the Altes Gefängnis prison, designed by Heinrich Bause in 1909; the Woermannhaus, built in 1906 with a prominent tower, is now a public library. Attractions in Swakopmund include a Swakopmund Museum, the National Marine Aquarium, a crystal gallery and spectacular sand dunes near Langstrand south of the Swakop River. Outside the city, the Rossmund Desert Golf Course is one of only five all-grass desert golf courses in the world. Nearby is a farm that offers camel rides to tourists and the Martin Luther steam locomotive, dating from 1896 and abandoned in the desert.
Swakopmund lies on the Trans-Namib Railway from Windhoek to Walvis Bay. It is served by Swakopmund Railway Station; the Herero called the place Otjozondjii. The name of the town is derived from the Nama word Tsoakhaub describing the Swakop River in flood carrying items in its riverbed, including dead animals, into the Atlantic Ocean. However, Prof. Peter Raper, Honorary Professor: Linguistics, at the University of the Free State points out that the name for Swakopmund is based on the San language, namely from “xwaka” and “ob”; the German settlers changed it to Swachaub, when in 1896 the district was proclaimed, the version Swakopmund was introduced. Captain Curt von François founded Swakopmund in 1892 as the main harbour for the Imperial German colony—the deep sea harbour at Walvis Bay belonged to the British; the founding date was on August 8. Swakopmund was chosen for its availability of fresh water, because other sites further north such as Cape Cross were found unsuitable; the site did, not offer any natural protection to ships lying off the coast, a geographical feature not found along Namibia's coast.
When the first 120 Schutztruppe soldiers and 40 settlers were offloaded at Swakopmund, they had to dig caves into the sand for shelter. The offloading was done by Kru tribesmen from Liberia. Woermann-Linie, the operator of the shipping route to Germany, employed 600 Kru at that time. Swakopmund became the main port for imports and exports for the whole territory, was one of six towns which received municipal status in 1909. Many government offices for German South West Africa had offices in Swakopmund. During the Herero Wars a concentration camp for Herero people was operated in town. Inmates were forced into slave labour. Soon, the harbour created by the "Mole" silted up, in 1905 work was started on a wooden jetty, but in the long run this was inadequate. In 1914 construction of a steel jetty was therefore commenced, the remains of which can still be seen today. After the First World War it became a pedestrian walkway, it was declared structurally unsound and was closed to the public for seven years, in 2006 renovations to the portion supported by concrete pillars were completed, with a seafood restaurant and sushi bar being added to the end portion of the steel portion of the jetty soon after.
A new timber walkway was added onto the existing steel structure, the steel portion of the jetty reopened to the public in late 2010. Trading and shipping companies founded branches in Swakopmund. A number of these buildings still exist today. After German South West Africa was taken over by the Union of South Africa in 1915, all harbour activities were transferred from Swakopmund to Walvis Bay. Many central government services ceased. Businesses closed down, the number of inhabitants diminished, the town became less prosperous. However, the natural potential of Swakopmund as a holiday resort was recognised, this potential has subsequently been developed. Today tourism-related services form an important part of the town's economy. After Namibian independence from South Africa in 1990 many street names were changed from their original German, or in some cases, Afrikaans names, to honour Namibians, predominantly Namibians of black heritage. For example, in 2001, then-president of Namibia Sam Nujoma renamed the main street Sam Nujoma Avenue in honour of himself.
Swakopmund is governed by a municipal council. Namibia's ruling SWAPO party won the 2010 local authority election with 4,496 votes, followed by the local Swakopmund Residents Association, the United Democratic Front, the Rally for Democracy and Progress, the National Unity Democratic Organisation; the 2015 local authority election was again won by SWAPO. One seat each was won by the UDF, the SRA, the Democratic Turnhalle Alliance, NUDO. There are the following districts and suburbs in Swakopmund: Town Centre Vineta Meile 4 Vogelstrand Waterfront Mondesa Tamariskia Democratic Resettlement Community The Democratic Resettlement Community is an informal settlement in Swakopmund, it was founded in 2001 as temporary housing for people waiting for subsidized housing in the city. Most inhabitants of the town live in