京津唐地区地震灾害和危险性评估

利用我国京津唐地区500年以来记录较完整的历史地震烈度资料，尝试进行了地震灾害与危险性分析，以提供制定抗震设防基本参数或烈度的参考.首先，我们用ArcGIS把这些历史烈度资料进行了数字化，并把研究区分成 0.1°×0.1°的小方格.然后，我们对烈度资料进行了统计分析，得到每个小方格的地震烈度-频度关系（即灾害曲线）.最后，基于地震发生遵从泊松分布的假定，利用灾害曲线估算了京津唐地区的地震风险，即在未来一段时间内(如 50年)该地区遭受某一地震烈度(如Ⅶ，Ⅷ，或Ⅸ度)的超越概率.同时，我们还估算了50年超越概率10%所对应的地震烈度，如：北京为Ⅸ，天津为Ⅸ，唐山为≥Ⅸ，保定为Ⅷ，廊坊为Ⅸ.研究结果表明，京津唐地区有较高的地震危险性，现行的抗震设防要求可能偏低.

Seismic hazard and risk assessments for Beijing-Tianjin-Tangshan area, China

This paper attempts to analyze seismic hazard and risk in Beijing-Tianjin-Tangshan, China, area from 500-year intensity observations, and to provide the basic parameters or intensities for seismic design and other mitigation considerations. First, we digitized the intensity observations (maps) using ArcGIS with a cell size of 0. 1 degree×0. 1 degree. Second, we performed a statistical analysis on the digitized intensity data and derived intensity-frequency relationship (hazard curve) for each cell. Finally, we estimated seismic risk in terms of a probability that intensity exceeds Ⅶ,Ⅷ, or IX in a certain periods (I. E. , 50years) based on the assumption of a Poisson distribution for earthquake occurrence. We also estimated the corresponding intensity with 10 percent probability of exceedance in 50 years. The results shows that the area has high seismic risk and the current design requirement for the area may be not adequate.