Spatial Multicriteria Decision Analysis of Flood Risks in Aging-Dam Management in China: A Framework and Case Study

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.

Simulation of Water Environmental Capacity and Pollution Load Reduction Using QUAL2K for Water Environmental Management

“…Therefore, the key to protection of the water environment of Taihu Lake is interception of the pollutants that discharge into Taihu Lake from various sources. The rational use of water resources has become a very important national policy issue in recent years and great efforts have been made to develop water environmental management strategies to ensure good water quality and sufficient water supply [5,6,7,8]. In this respect, water quality modeling is increasingly recognized as an effective tool for water quality management decision-making [9].…”

Sustainability-Based Flood Hazard Mapping of the Swannanoa River Watershed

“…Potential impact on people lives is considered as the indicator of social flood hazard [15,42,43]. A combination of flood depth and velocity is used to estimate the hazard to people lives according to the taxonomy by Assistant Commissioner-Engineering and Research (ACER) [44].…”

“…Therefore, alternate methods suggested in other countries should be used through literature review. Here, potential erosion and pollution are used as the indicators of the environmental hazard aligned with earlier studies [15,42,43,45,46]. Flood impulse (i.e., product of flood depth and velocity) is used to represent the former [45,47] and duration is used to represent the latter [47].…”

Dam removal and anadromous salmonid (Oncorhynchus spp.) conservation in California

“…General frameworks exist to assess the ecological benefits and detriments of dam removal Whitelaw and MacMullan 2002;Yang et al 2011;Zheng and Hobbs 2013). However, not all elements presented in these studies are applicable to dam removal in areas with Mediterranean climate such as California.…”