|
Typhoon Nanmadol, known in the Philippines as Typhoon Mina, was the strongest tropical cyclone in 2011 to hit the Philippines and also the first of the year to directly impact Taiwan and the rest of the Republic of China (ROC). It was the eleventh named storm, the seventh severe tropical storm and the fourth typhoon of the 2011 Pacific typhoon season. Nanmadol made a total of three landfalls killing 26, and causing widespread damage worth US$26,464,591. The name ''Nanmadol'' is derived from Nan Madol, a ruined city that lies off the eastern shore of the island of Pohnpei that was the capital of the Saudeleur dynasty until about AD 1500.〔(Nan Madol, Madolenihmw, Pohnpei ) William Ayres, Department of Anthropology University Of Oregon, Accessed 26th September 2007〕 The area of low pressure that was about to become Nanmadol formedon August 19. It drifted north and became a tropical depression on August 21, a tropical storm on August 23 and a typhoon on the same night. Nanmadol reached peak strength with winds of 105 knots (195 km/h; 121 mph) (10-minute sustained) and 140 knots (260 km/h; 160 mph) (1-minute sustained) threatening the Philippines with heavy rain and flash flooding. The Filipinos were warned about high waves, strong winds and very heavy rains over the weekend with storm signal 4 raised in parts of the Nation. There, strong winds toppled trees, power and communication lines triggering power outages in the provinces of Cagayan and Isabela. Rivers swelled up on receiving tons on rainwater, overflowing at least six bridges across the two provinces. The typhoon hardly moved in 24 hours bringing relentless rains to the archipelago causing the retaining wall of Baguio's dump facility to collapse. Also, major power lines in the nation were pulled down causing total power failures in Benguet, Cagayan, Apayao, Kalinga and mountain provinces. In Taiwan, the Central Weather Bureau issued a sea warnings instructing all ships passing through the Bashi Channel to stay updated about the typhoon. The president of Taiwan ordered evacuations of thousands of people from vulnerable areas, saying that a slow moving typhoon could result in more damages and casualties than normal. Some 35,000 soldiers were ordered to be ready to help out as many people as possible when the typhoon strikes. The soldiers were in possession of portable power generators, water pumps and amphibious assault vehicles. The Taiwan Railway Administration halted services on the South-Link Line in fear that heavy rain could trigger landslides and cause rail-accidents. The Directorate-General of Highways closed the Suhua Highway saying that the area through which the highway was built is more prone to landslides during typhoons. After landfall, Nanmadol dumped very heavy rainfall over the nation. Some 528 millimetres (20.8 in) of rain was dumped in Hualien County; 517 millimetres (20.4 in) in Hengchun, Pingtung County; 449 millimetres (17.7 in) in Taitung County; 292 millimetres (11.5 in) in Pinglin, New Taipei; 275 millimetres (10.8 in) in Kaohsiung; and 265 millimetres (10.4 in) in Taiping Mountain, Yilan County. The Council of Agriculture soon issued a red-alert for six riverside areas advising people that are at a high risk of mudslides after heavy torrential rains dumped by the typhoon. Even long after Nanmadol left Taiwan, heavy rain continued to batter the nation. Several parts of the nation saw rains of more than on meter and 1.5 meters with Pingtung County was the hardest hit of all. Kinmen was struck by Nanmadol and was covered by the storm-level wind radius for extended period because of the slow motion of the typhoon. Another Fujianese county, the Matsu Islands, was also affected by Nanmadol.〔 *http://www.kinmen.gov.tw/Layout/sub_E/News_NewsPrint.aspx?NewsID=86515 *http://www.kcbfa.gov.tw/BusSite/wSite/ct?xItem=3343&ctNode=215&mp=6 *http://www.matsu-news.gov.tw/news_info.php?CMD=open&UID=131000〕 In China, Local authorities started calling back several thousands of ships informing them about the heavy rain the typhoon was pouring. The storm was expected to bring heavy torrential rains and flash flooding as is makes landfall on the southern part of Fujian province. Bullet trains along the Wenzhou-Fuzhou and Fuzhou-Xiamen high-speed rail lines were ordered to either operate slowly or suspend services completely if the surveillance system detects any hazards. Also, the shipping route linking Xiamen, in east China's Fujian Province, and Jinmen, in Taiwan was closed at 14:00 local time as the storm entered the strait. Nanmadol made landfall as a weak tropical cyclone bringing heavy rains, prompting local authorities to issue flood and landslide warnings. Thousands of fishermen's livelihoods were at risks of being washed away. Evacuations were being carried out with local residents being taken to higher grounds. == Meteorological history == Late on August 19, an area of low pressure developed north of Palau.〔(【引用サイトリンク】url=http://www.webcitation.org/61523IHCv )〕 Early on August 20, the system became more organized and developed a low-level circulation center.〔(【引用サイトリンク】url=http://www.webcitation.org/6151uraG4 )〕 The system then turned north and continued to drift north until on August 21, when the Japan Meteorological Agency (JMA) upgraded the low pressure area to a tropical depression east of Philippines. The Joint Typhoon Warning Center (JTWC) also issued a Tropical Cyclone Formation Alert (TCFA) on the system reporting that the system was becoming more well organized.〔(【引用サイトリンク】url=http://www.webcitation.org/617xVE4zj )〕 Later that day, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) started monitoring the system as a tropical depression and named it ''Mina''.〔(【引用サイトリンク】url=http://www.webcitation.org/617CyfYqN )〕 Late on August 22, the system became more well organized prompting the JTWC to initiate advisories on the system, designating it 14W.〔(【引用サイトリンク】url=http://www.webcitation.org/619JaMLGU )〕 On August 23, the JMA upgraded 14W to a tropical storm, naming it ''Nanmadol''. Overnight, the system continued to intensify and early on August 24, the JMA upgraded Nanmadol to a severe tropical storm. Later that day, convective banding improved and Nanmadol developed an eye-like feature.〔(【引用サイトリンク】url=http://www.webcitation.org/61Ar7ANnb )〕 As a result, Nanmadol continued to intensify rapidly and became a typhoon, by midnight, that day.〔(【引用サイトリンク】url=http://www.webcitation.org/61CE5dEkt )〕 The JTWC originally anticipated a fujiwhara effect of Nanmadol on Talas, a weaker tropical cyclone to the east of Nanmadol.〔(【引用サイトリンク】url=http://www.webcitation.org/61HCYmjgo )〕 However, the two cyclones moved far away from each other with at least a of distance between them. This prompted the JTWC to change its forecast on the system, from turning east and interacting with Talas, to move west and hit the Philippines.〔(【引用サイトリンク】url=http://www.webcitation.org/61HCbaAnF )〕 On August 26, Nanmadol reached peak strength with winds of (10-minute sustained) and (1-minute sustained) reaching category 5 status on the SSHS. The typhoon developed a large eye with a diameter of with highly symmetric deep convective bands wrapped into it.〔(【引用サイトリンク】url=http://www.webcitation.org/61FM7Ihjz )〕 Nanmadol continued to drift north west and made landfall over Gonzaga, Cagayan, Philippines with strong winds of over . After interacting with land, the eye of Nanmadol became cloud filled and the eyewall in the northern semicircle became eroded causing the system to weaken.〔(【引用サイトリンク】url=http://www.webcitation.org/61FLrAzqV )〕 However, the typhoon maintained tightly curved convective banding and central convection for long time after the landfall. The typhoon maintained a favorable upper level outflow, though located in a mid-level subtropical ridge.〔(【引用サイトリンク】url=http://www.webcitation.org/61Fdlvm7D )〕 As Nanmadol started moving away from Luzon, the eye became more evident and central convection became re-consolidated with curved banding.〔(【引用サイトリンク】url=http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/warnings/wp1411prog.txt )〕 However, the typhoon did not maintain this for long. Nanmadol could not recover very well from interacting with land and started weakening as the cloud tops were warming up and the eye was being filled with clouds again.〔(【引用サイトリンク】url=http://www.webcitation.org/61GimZ5S1 )〕 During the early hours of August 28, Nanmadol struggled to strengthen after passing over the Babuyan Islands. The eye became completely cloud-filled and the outermost rainbands crossed over Taiwan.〔(【引用サイトリンク】url=http://www.webcitation.org/61Gj3vTzp )〕 This prompted the JMA to downgrade Nanmadol to a severe tropical storm.〔(【引用サイトリンク】url=http://www.webcitation.org/61GjSiPCT )〕 Later that day, the central convection started depleting as the system approached southern Taiwan. At that time, it was located approximately south of Taipei in the periphery of a mid-level subtropical ridge.〔(【引用サイトリンク】url=http://www.webcitation.org/61H8b6lai )〕 Nanmadol continued to weaken as it approached Taiwan and the winds rapidly decreased to under (1-minute sustained), making Nanmadol a minimal typhoon on the SSHS. It maintained a poorly defined eyewall to its south with convective banding wrapped into the cloud filled center.〔(【引用サイトリンク】url=http://www.webcitation.org/61HHfLV4j )〕 Late on August 28, Nanmadol made its second landfall over Dawu Township in Taitung County, Taiwan and started weakening.〔(【引用サイトリンク】url=http://www.webcitation.org/61Hrvwemr )〕 After a tremendous burst of convection over southern Taiwan, land interaction severely weakened the system. A strong subtropical ridge towards the north-east of the storm started pushing Nanmadol towards the northwest at an increasingly fast pace.〔(【引用サイトリンク】url=http://www.webcitation.org/61IR0NtqX )〕 Soon, Nanmadol accelerated towards the northwest and entered the Taiwan Strait, with fragmented convective bands wrapped into an adequately defined center. Landfall weakened the system rapidly prompting the JTWC to downgrade Nanmadol to a tropical storm with winds of under .〔(【引用サイトリンク】url=http://www.webcitation.org/61IRIeI0q )〕 Eventually, the JMA too downgraded Nanmadol to a tropical storm with winds of under . At that time, it was located to the west of Tainan, Taiwan with winds spreading towards the north-east and towards the south-west.〔(【引用サイトリンク】url=http://www.webcitation.org/61IjBegqE )〕 On August 30, Nanmadol slowed moving and became almost stationary. The low level circulation center became exposed and the curved convective banding moved to the south of the system.〔(【引用サイトリンク】url=http://www.webcitation.org/61JwtsXiz )〕 Soon it started experiencing strong wind shear and continued weakening. The shear pushed convection approximately south of the LLCC. The system also accelerated towards China at and weakened to a minimal tropical storm.〔(【引用サイトリンク】url=http://www.webcitation.org/61Jxo6MAL )〕 After its third landfall over Fujian, China, Nanmadol weakened rapidly prompting both the JTWC and the JMA to issue their final warnings on the system.〔(【引用サイトリンク】url=http://www.webcitation.org/61LKsHVsq )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Typhoon Nanmadol (2011)」の詳細全文を読む スポンサード リンク
|