Hazard Risk Analysis of Typhoon Damage by Applying Grey System Theory

Over the last three decades, Hsichih City has become a rapidly developed urban area in the Taipei Basin. Enormous flood damage is frequently caused by typhoons between June and October every year, due to the high population density, low-lying terrain and meandering course of the Keelung River that runs from east to west. An atypical typhoon event, Typhoon Nali on September 16, 2001, attacked northern Taiwan and led to extremely severe inundation damage and serious loss of property in that booming city area. This paper analyzes the hazard risk of typhoon damage in the Hsichih area, using grey system theory. First, the basic data of every unit village were collected and analyzed using the Geographic Information System. Second, the inundation was simulated using a 2-D unsteady hydraulic model. Third, the basic data with property losses and a map of inundation zones and the depths of Typhoon Nali, are used to develop a grey model GM(1,3) of the spatial index. The model was simulated and verified according to the original data. Then, the various maps of inundation zones and depths of eight different return periods (1.1, 2, 5, 10, 25, 50, 100 and 200 years) were adopted and the GM(1,3) of the spatial index applied; the total property losses under the above conditions were sequentially determined. Finally, the hazard risk of typhoon damage in the Hsichih area was determined from the losses and their corresponding frequencies. The results confirmed that the grey system model could be applied to estimate the hazard risk of typhoon damage in the study area.

並列關鍵字

Hazard risk of typhoon damage ； 2-D unsteady hydraulic model ； GM(1,3) of the spatial index

國際替代計量

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