Effectiveness of an adaptive flood management strategy using riparian risk assessment and a tolerability criterion

Abstract

Owing to climate change, torrential rains and typhoons have become more frequent. However, to cope with this threat, conventional flood management suffers from limitations and difficulties because of the practice of uniform flood prevention measures being applied to all stream sections according to river grade classification. A wide array of measures should be considered to differentiate flood protection targets: adaptive flood management strategy is one such effort. One obstacle, however, to introducing such a measure is lack of clarity over how to divide quantitatively the degree of risk from flooding. In this study, we undertook quantitative risk assessment to determine the risk level in a riparian zone. We compared our results with statistically derived societal risk limits to determine whether the risk level was acceptable within the framework of the tolerance risk limit. We found that the flood risk could be reduced through adaptive flood management.