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611.
近年来我国海洋灾害损失及防灾减灾策略 总被引:2,自引:0,他引:2
我国是世界上海洋灾害最为严重的少数国家之一。近年来,由风暴潮、灾害性海浪、赤潮、海冰、海平面上升等海洋灾害带来的经济损失和人员伤亡越来越严重,其中,风暴潮是影响我国沿海地区最为严重的海洋灾害。通过建立海岸生态防护网、提高沿海地区防潮工程标准、开发海洋灾害监测和预报系统、实行海洋数据资料和信息共享等方法,降低海洋灾害发生的机率,减少海洋灾害损失。 相似文献
612.
In the English Channel, extreme surge heights did not occur at the time of extreme high tides during the last decades and
maximum recorded heights usually do not exceed the maximum astronomical tide by more than a few decimetres. To understand
whether this lack of coincidence may be due to specific phenomena or only to chance, we have studied hourly tide records lasting
a few decades from nine English and nine French stations as well as air pressure and wind data from nearby meteorological
observatories. Among the case studies of moderate flooding at several coastal stations occurring during spring tide, we have
selected those of 24–25/10/1980 and of 30/01/1983 to 02/02/1983 as representative of a normal situation without any special
chance. The third case study 26–28/02/1990 was potentially more dangerous because of the storm intensity and duration; however,
by chance, surge peaks occurred near the low tide. Finally, the propagation of the surge peak of 15–16/10/1987, which reached
the maximum height recorded during all the instrumental period at several stations, has been followed all along the English
Channel, using the hourly records of 12 tide-gauge stations and of 16 meteorological stations. The surge peak of this great
storm, probably the strongest in the last two centuries, occurred everywhere at high tide and spread with the same velocity
of the tidal wave. Fortunately, no major flooding occurred because it was the day after a neap tide. In conclusion, some good
fortune has saved the low coastal areas of the English Channel from major floods during the last decades. However, the occurrence
of the peak of a strong storm surge arriving near the western entrance of the Channel at the time of a great astronomical
high tide is a possible event that could be devastating along both sides of the Channel coasts.
Main parts of this paper have been presented orally in June 2005 at the joint INQUA–IGCP 495 Meeting “Dunkerque 2005” and
in February 2006 at the ASLO-TOS-AGU “Ocean Sciences Meeting” (Honolulu, HI). 相似文献
613.
地震作用下立式储液罐罐壁“象足”变形仿真分析 总被引:1,自引:0,他引:1
基于ANSYS软件建立了考虑液体晃动和罐底提离立式储液罐有限元模型,分别进行了水平地震和竖向地震作用下罐壁“象足”变形分析。分析表明:立式储液罐罐壁“象足”变形主要是由罐壁纵向压应力超过临界应力而产生的局部屈曲破坏,并非强度破坏。因罐底提离导致的罐底与基础反复撞击加大了作用在罐壁上的应力,使罐壁底部“象足”变形不断发展,最终导致罐壁撕裂。在完全相同地震加速度作用下,水平地震作用比竖向地震作用罐壁更早更容易进入屈曲状态,产生“象足”变形。 相似文献
614.
A nonlinear shallow water model in cylindrical polar coordinate system is developed, using an explicit finite difference scheme with a very fine resolution, to compute different aspects of tsunami at North Sumatra and the adjacent island Simeulue in Indonesia, and the Penang Island in Peninsular Malaysia. The pole of the frame is placed on the mainland of Penang (100.5°E) and the model area extends up to the west of Sumatra (87.5°E). The model is applied to simulate the propagation of tsunami wave towards North Sumatra, Simeulue and Penang Islands associated with Indonesian tsunami of 26 December 2004. The model is also applied to compute water levels along the coastal belts of those islands. Computed and observed water level data are found to be in good agreement and North Sumatra is found to be vulnerable for very high surges. The computed and observed arrival times of high surges are also in reasonable agreement everywhere. Further studies are carried out to investigate the effect of convective terms and it is found that their effects are insignificant in tsunami propagation and weakly significant for wave amplitude very near to the coast. 相似文献
615.
针对电源类电涌保护器的试验可进行分类,电源保护器的测试方法除了有规范的要求外,还有许多具体的问题需要研究解决。针对SPD测试中出现的问题进行分析,主要围绕M OV电阻片的漏电流与相关测试所出现的现象进行讨论,对击穿、闪络、燃烧问题进行研究,归纳了现今电涌保护器最常出现的问题。 相似文献
616.
Vulnerability from storm surges and cyclone wind fields on the coast of Andhra Pradesh,India 总被引:2,自引:0,他引:2
The results presented here are from a study conducted for the government of the state of Andhra Pradesh (GOAP) in India, as
part of a World Bank project on cyclone mitigation. A set of detailed maps were prepared depicting the Physical Vulnerability
(PV), specifically storm surge inundation zones are shown for frequent occurrence, 50-year return period, likely scenario
for global warming and extreme global warming. Similarly vulnerable areas from strong wind field from tropical cyclones (TCS)
are also presented for the same four parameters. Vulnerability zones are presented from a social point of view also based
upon certain socio-economic parameters that were included in determining the overall vulnerability of each Mandal in a coastal
district (a Mandal represents a group of villages and towns) include: population, senior citizens, women, children under different
age groups, type of housing, income level, cyclone shelters, hospitals and medical centres, schools and caste based population.
The study is about scenarios that could happen if global warming and the predicted intensification of TCS actually occur as
predicted by some numerical models. 相似文献
617.
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619.
620.
概化的Tank模型及其在龙羊峡水库汛期旬平均入库流量预报中的应用 总被引:3,自引:2,他引:3
Tank模型(又称为水箱模型),是一种用于流域径流预报的确定性水文模型,根据龙羊峡水库入库主要产流区--黄河上游唐乃亥水文站以上流域下垫面条件下产汇流特性,将其概化为以降雨量为输入,径流量为输出的单孔出流的线性水箱,工用于该水库汛期旬平均入库流量的预报,经对历史资料进行拟合和试验预报的 结果表明,该模型具有较高的预报精度,现已应用于黄河上游龙羊峡水库汛期旬平均入库来水量的中期预报中,取得了十分显著的经济效益。 相似文献