水库土坝漫坝风险度评价方法及应用研究

Study on evaluation method for overtopping risk degree of reservoir earth dam

根据联合国对自然灾害风险的定义及其定量表达式,给出了水库土坝漫坝风险评价模式。提出危险度转换赋值函数,将漫坝概率转换为漫坝危险度,并用财产和人口两种基本类型指标来反映漫坝易损性,从而给出财产和人口指标的定量表达式和转换赋值函数,使漫坝易损度定量表达为财产指标转换赋值与人口指标转换赋值加权平均的平方根。最后建立了漫坝风险度的定量评估等级,赋予相应的风险指南,为漫坝风险评判提供依据。本方法应用于分析广西澄碧河水库土坝工程,计算结果表明,在现有条件下该水库汛限水位的提高幅度不宜超过1.0m。

The evaluation pattern that risk degree is product of danger degree and vulnerability were introduced based on natural disasters risk expression which was recommended by the Humanitation Affairs Department of United Nations.The transformed values function was suggested to transfer overtopping probability into danger degree,which was measured on a scale of 0 to 1.The property index and population index were used to measure the vulnerability of overtopping of a dam.The calcutation method for quantitatively determining these indexes and corresponding transformed values function were proposed mathematically.The vulnerability is the square root of the weighted average of these two indexes,which were also measured on a scale of 0 to 1.The mathematical evaluation ranks for overtopping risk degree were established,and their guidelines were explained in detail.The proposed method was used for studying the Chengbihe reservoir in Guangxi province,the analysis results indicated that the maximum of flood control water level of the reservoir can be raised by 1.0m.