Limits...
Spatial multicriteria decision analysis of flood risks in aging-dam management in China: a framework and case study.

Yang M, Qian X, Zhang Y, Sheng J, Shen D, Ge Y - Int J Environ Res Public Health (2011)

Bottom Line: Approximately 30,000 dams in China are aging and are considered to be high-level risks.Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal.With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China. yngjyangmeng@gmail.com

ABSTRACT
Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

Show MeSH

Related in: MedlinePlus

Changes of multicriteria flood risk from risk under existing conditions in two scenarios: (a) dam decommissioning scenario and (b) dam rehabilitation scenario.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC3108115&req=5

f8-ijerph-08-01368: Changes of multicriteria flood risk from risk under existing conditions in two scenarios: (a) dam decommissioning scenario and (b) dam rehabilitation scenario.

Mentions: The multicriteria flood risks of the two scenarios were also computed using the mean weight sets shown in Table 5. The spatial patterns of the changes in multicriteria risk from risk under existing conditions are shown in Figure 8. In the dam decommissioning scenario, areas with increased risk (<0.20) were found in some of the residential and commercial buildings (e.g., those in which the inundation depth was increased by more than 0.15 m during a 50-year flood event; Figure 8a). Other elements in the flood zone had risks that were decreased by up to 0.25 (Figure 8a) because the dam-failure probability was significantly reduced when the dam was decommissioned (Table 4). The dam rehabilitation scenario reduced the risk by up to 0.25 in the most affected areas as a combined result of the lower water depth during a 50-year flood and the smaller probability of dam failure (Table 4). However, areas at the fringes of the inundation zone were found to have increased risk because the dam rehabilitation alternative slightly enlarged the extent of inundation (Figure 8b).


Spatial multicriteria decision analysis of flood risks in aging-dam management in China: a framework and case study.

Yang M, Qian X, Zhang Y, Sheng J, Shen D, Ge Y - Int J Environ Res Public Health (2011)

Changes of multicriteria flood risk from risk under existing conditions in two scenarios: (a) dam decommissioning scenario and (b) dam rehabilitation scenario.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3108115&req=5

f8-ijerph-08-01368: Changes of multicriteria flood risk from risk under existing conditions in two scenarios: (a) dam decommissioning scenario and (b) dam rehabilitation scenario.
Mentions: The multicriteria flood risks of the two scenarios were also computed using the mean weight sets shown in Table 5. The spatial patterns of the changes in multicriteria risk from risk under existing conditions are shown in Figure 8. In the dam decommissioning scenario, areas with increased risk (<0.20) were found in some of the residential and commercial buildings (e.g., those in which the inundation depth was increased by more than 0.15 m during a 50-year flood event; Figure 8a). Other elements in the flood zone had risks that were decreased by up to 0.25 (Figure 8a) because the dam-failure probability was significantly reduced when the dam was decommissioned (Table 4). The dam rehabilitation scenario reduced the risk by up to 0.25 in the most affected areas as a combined result of the lower water depth during a 50-year flood and the smaller probability of dam failure (Table 4). However, areas at the fringes of the inundation zone were found to have increased risk because the dam rehabilitation alternative slightly enlarged the extent of inundation (Figure 8b).

Bottom Line: Approximately 30,000 dams in China are aging and are considered to be high-level risks.Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal.With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, China. yngjyangmeng@gmail.com

ABSTRACT
Approximately 30,000 dams in China are aging and are considered to be high-level risks. Developing a framework for analyzing spatial multicriteria flood risk is crucial to ranking management scenarios for these dams, especially in densely populated areas. Based on the theories of spatial multicriteria decision analysis, this report generalizes a framework consisting of scenario definition, problem structuring, criteria construction, spatial quantification of criteria, criteria weighting, decision rules, sensitivity analyses, and scenario appraisal. The framework is presented in detail by using a case study to rank dam rehabilitation, decommissioning and existing-condition scenarios. The results show that there was a serious inundation, and that a dam rehabilitation scenario could reduce the multicriteria flood risk by 0.25 in the most affected areas; this indicates a mean risk decrease of less than 23%. Although increased risk (<0.20) was found for some residential and commercial buildings, if the dam were to be decommissioned, the mean risk would not be greater than the current existing risk, indicating that the dam rehabilitation scenario had a higher rank for decreasing the flood risk than the decommissioning scenario, but that dam rehabilitation alone might be of little help in abating flood risk. With adjustments and improvement to the specific methods (according to the circumstances and available data) this framework may be applied to other sites.

Show MeSH
Related in: MedlinePlus