非均匀分布强震动台站的仪器地震烈度等震线生成方法

发布时间：2018-09-03 13:14

【摘要】：烈度等值线图包含了地震参数与地震影响场的重要信息。传统的地震烈度图编制要综合现场调查、遥感震害解译、强震观测记录等资料,投入人力物力大、耗时长,不能满足烈度速报对时效性的要求。目前烈度速报采用基于强震记录的仪器地震烈度,通过空间插值计算获得烈度等值线图。由于我国现有强震动台网的空间分布极不均匀、台站密度较小,地震发生时触发台站的数目往往较少,在生成仪器烈度等震线时结果往往不理想。针对这个问题,本文利用烈度的衰减规律对克里金插值方法进行了改进,通过衰减关系获取实验变差函数,研究了不同台网状况下克里金插值的特点,分析了克里金方法在触发台站稀疏时插值结果失真的原因,并提出了一种根据台网状况构建Voronoi补点的方法。本文的主要内容包括:(1)选择克里金插值方法作为研究对象,以实际地震事件为例进行插值计算,并与其它插值方法的结果对比,验证了克里金方法在计算仪器地震烈度等值线图上的优越性,根据我国台网实情指出了克里金方法在烈度等值线绘制过程中存在的问题。(2)研究克里金插值中变差函数的构建方法,指出我国现有台网条件下变差函数的难以回归拟合的状况,引入地震烈度衰减关系来构造变差函数。以人工建立的地震烈度影响场模型为研究对象,研究不同因素对于克里金插值结果的影响:首先,对比不同衰减关系得到的变差函数对插值结果的影响,给出建立变差函数的方法;其次,讨论数据误差对插值结果的影响,给出了插值数据的选取准则;再次,总结不同台网状况下克里金插值结果的特点,指出克里金插值产出的等值线图不闭合的情况,提出需要进行烈度补点;最后,对插值结果进行误差分析,找出克里金插值结果失真的原因,确定了采用补点的方法对克里金方法进行改进。(3)提出基于Voronoi图的克里金插值补点方法,对于等值线图不闭合的情况,利用生成台站Voronoi图寻找台网最稀疏的位置。在台网最稀疏位置增补虚拟台站,使得原本不闭合的等值线图闭合,并利用空隙角大小范围给出了基于Voronoi图补点原则。
[Abstract]:The isoline map of intensity contains important information of seismic parameters and seismic impact field. The traditional compilation of seismic intensity map should be comprehensive field investigation, remote sensing seismic damage interpretation, strong earthquake observation records, and other data, invest a lot of manpower and material resources, take a long time, can not meet the intensity of rapid reporting requirements for timeliness. At present, the seismicity of instrument based on strong earthquake record is used in fast intensity report, and the isoline map of intensity is obtained by spatial interpolation. Because the spatial distribution of the existing strong seismic network in China is extremely uneven, the density of stations is relatively small, the number of triggering stations is often less when earthquakes occur, and the results are often not ideal when generating the isoseismic lines of instrument intensity. Aiming at this problem, this paper improves the Kriging interpolation method by using the attenuation law of intensity, obtains the experimental variation function by the attenuation relation, and studies the characteristics of Kriging interpolation under different network conditions. This paper analyzes the causes of distortion of interpolation results of Kriging method when triggering stations are sparse, and puts forward a method to construct Voronoi complement points according to network conditions. The main contents of this paper are as follows: (1) the Kriging interpolation method is selected as the research object, and the actual seismic events are taken as an example to carry out the interpolation calculation, and the results are compared with the results of other interpolation methods. The superiority of Kriging method in the isoline map of seismic intensity is verified. According to the reality of Chinese network, the problems of Kriging method in intensity isoline drawing are pointed out. (2) the construction method of variation function in Kriging interpolation is studied, and the situation that variation function is difficult to be regressed and fitted under the condition of network in our country is pointed out. The variation function is constructed by introducing the attenuation relation of seismic intensity. The effect of different factors on the results of Kriging interpolation is studied by using the artificial model of seismic intensity influence field. Firstly, the effects of variation function obtained by different attenuation relations on the interpolation results are compared. The method of establishing variation function is given. Secondly, the influence of data error on interpolation results is discussed, and the selection criteria of interpolation data are given. Thirdly, the characteristics of Kriging interpolation results under different network conditions are summarized. It is pointed out that the isoline map produced by Kriging interpolation is not closed, and the intensity complement points are proposed. Finally, the error analysis of the interpolation results is carried out to find out the reasons for the distortion of Kriging interpolation results. The method of complement point is used to improve the Kriging method. (3) the Kriging interpolation complement method based on Voronoi graph is proposed. In the case of isoline graph not closed, the station Voronoi graph is used to find the most sparse position of the network. Virtual stations are added to the most sparse position of the network, which makes the original unclosed isoline graphs close, and the principle of complement points based on Voronoi diagram is given by using the gap angle range.
【学位授予单位】：中国地震局工程力学研究所
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P315

【参考文献】