Risk Assessment of Emergency Disposal of Reservoir Dam in High Altitude Areas

Some typical problems of reservoir dam safety and management in high altitude areas were summarized in this paper and new issues for reservoir dam emergency disposal in such areas were pointed out. Based on the above discussions, the emergency incident of the exceeding standard flood of Wenquan reservoir, which locates in high altitude areas, was analyzed as an example for illustrating the emergency disposal scheme. Two different emergency disposal methods: renovation of the practical weir and construction of a new emergency spillway, were evaluated using risk criterias of people's lives security, economic, environmental and social based on risk assessment. Some conclusions were drawn from this research: (I) The renovation of the practical weir is more economical than the construction of a new spillway, if the drainage of the exceeding standard flood of reservoir can be satisfied (2) Under the criterion of social risks, both two methods are acceptable risk. Under the criterion of life, economic and environmental risks, construction of an emergent spillway all are acceptable risks, while the renovation of the practical weir all are tolerable risks. Therefore the construction of a new emergent spillway method has a lower risk.