我国地震区划图的初步检验

Preliminary Inspection of Seismic Zoning Maps in China

借助GIS的空间操作和空间分析的功能对我国四张地震区划图(1957年发表的中国地震区域划分图、1977年颁布的中国地震烈度区划图、1990年颁布的中国地震烈度区划图和2001年颁布的中国地震动参数区划图)分别用发表以后大陆地区发生的、经震害调查的5级以上浅源地震的等震线与之叠合,统计出相应时段中实际发生的不同烈度区超过区划图上烈度1度、2度或更多的总面积及相应的百分比;根据各个区划图表达的地震危险性定义制定标准检验了相应的可靠程度。通过与相应时段地震人员伤亡、经济损失的对比分析,指出了地震区划方法的进一步改进要把重点放在提高对7级以上大地震可能发生部位的识别上。

Four seismic zoning maps of China respectively published in 1957,1977,1990,and 2001 are inspected in this study.The isoseismals of shallow earthquakes of M ≥5occurring in the mainland of China after the maps were published are overlaid on the maps by means of Geographic Information System（GIS）.The total areas with observed intensity of at least 1°larger than the corresponding intensity on the maps are summed.The percentages of areas with positive intensity difference against the entire mainland of China are calculated by the GIS function of special manipulation and analysis.The reliability of each map is tested according to its hazard definition.A key point for improving zoning methods is suggested by recognizing regions with the potential for large earthquakes of M ≥7on the basis of statistics of deaths,injuries,and losses by earthquakes during the four time periods.