Regional Flood Risk Assessment and Uncertainty Analysis
Date Issued
2005
Date
2005
Author(s)
Kang, Jui-Lin
DOI
zh-TW
Abstract
Flood risk management is an important issue in Taiwan because the island suffers from frequent flood attacks especially for the last decade. Flood risk analysis is the starting point of flood management and flood loss assessment is the basis of flood risk analysis. This paper focuses on the studies of regional flood loss and flood risk assessment as well as the uncertainties associated with them.
Risk is usually thought of as the occurrence possibility of an event. Flood risk is defined by the United Nation disaster relief office as the expected value of flood loss. Since multiple events may occur during a year, the expected loss of a single flood event can’t be considered as the regional flood risk. Regional average annual flood loss of events with different occurrence probabilities may be a more proper index to the regional flood risk.
There are different approaches to the regional flood loss assessments. The depth-damage curve was used in this study to assess regional flood loss. A grid-based regional flood loss model was proposed which takes into account the variations of socio-economic activities among different grid cells. Through the use of a set of flood hazard potential data with different return periods, regional flood risks were presented as flood loss-exceedance probability (EP) curve. The area under the EP curve represents the expected annual flood loss for the region. A flood risk map was also built with this grid data approach which made the spatial risk presentation n possible.
Uncertainty is an inevitable part of the assertion of knowledge. The result of flood risk analysis also had uncertainty. The variations of flood loss data at the same flooding depth were studied. Confidence intervals for regional flood loss and flood risk were constructed through a system simulation approach using the flood loss probability density functions. Townships of Si-Jhih and Ci-Du in northern Taiwan were used as a study area for the demonstration of these proposed algorithms.
Subjects
洪災
損失曲線
風險圖
未確定性
flood
loss curve
risk map
uncertainty
SDGs
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-F84622006-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):5e0812be12acbc7789bfa598356f5ccb