Modeling the risk assessment of landslide-dammed lakes based on the emergency response measures in Wenchuan earthquake, 2008, China

Abstract

With the rapid development of urbanization and climate change, the frequency and degree of the natural hazards and extreme weather events have increased, such as the earthquake, flood, and torrential rain. And the landslide-dammed lake as the secondary disaster of these hazards has become a major threat to many countries. So from twentieth century, many countries have begun to explore the effective emergency response method to reduce the danger of the landslide-dammed lake to the surrounded environment and people. Particularly in China, with successfully dealing with three high-risk landslide-dammed lakes in recent 10 years, the Chinese government has accumulated a great deal of experience in managing the landslide-dammed lakes. So in this paper, based on the Chinese and many other countries’ emergency response experience of successfully managing the landslide-dammed lakes, we build an outburst time–predicted model which can use the Dimensionless blockage index value to predict the outburst time of the landslide-dammed lakes. Based on the urgent time in the process of emergency response to the landslide-dammed lake, we build an integrated risk assessment model with the gray relational analysis and Technique for order preference by similarity to an ideal solution approach to evaluate the risk value and judge the risk level of the landslide-dammed lake from three aspects (the stability of the landslide-dammed lake, the hydrological environment, and the vulnerability factor of the surrounding environment). These two models can quickly and accurately determine the risk level of landslide-dammed lake in case of lack of complete and detailed data. So it would provide an important reference for government to make the scientific and effective emergency response plan to deal with the extremely high-risk landslide-dammed lake disasters in the future.