CN105510962A - Method for simulation of scope of aftershock - Google Patents

Abstract

The invention discloses a method for simulating the influence range of aftershocks. The projection surface transforms the coordinate system into the projected coordinate system; using the correlation analysis method of point pattern analysis, the relationship model of the distance between aftershock points is obtained by fitting, and it is decomposed into different scale-free intervals. The value is smaller than the value in the next adjacent unscaled interval; the kernel density simulation analysis of the point is carried out in the unscaled interval, and the layers corresponding to the unscaled interval are respectively obtained; the adjacent layers L _i and L _i are judged For the occlusion content between ₊₁ , after removing the corresponding occlusion content of Li ₊₁ , Li and _Li+1 are combined, all layers are processed in turn, and the combined layer R _i is output _. The invention is based on the publicly released point data of earthquake aftershocks, and can quickly evaluate the range of earthquake influence.

Description

A Simulation Method of Aftershock Influence Range

technical field

The invention relates to the technical field of seismic measurement, in particular to a method for simulating the influence range of aftershocks.

Background technique

Earthquake impact range simulation is one of the basic tasks of earthquake disaster comprehensive assessment. Earthquake disasters are sudden and predictable, and their frequency has been high in recent years. The associated severe secondary disasters have a great impact on society. In this context, it is obvious that the practical value of the research is based on the public and available earthquake aftershock point sequence data to quickly simulate the range of earthquake influence.

Existing methods for assessing the impact range of earthquake disasters mostly focus on parameters such as the maximum earthquake magnitude and ground peak acceleration, and implement regional assessment of the impact range of earthquake disasters. This method requires more earthquake physical parameters, so the process is cumbersome and operable Sex is not strong. Based on the publicly released point data of earthquake aftershocks, the impact range of the earthquake can be quickly estimated, the data source is simple, and the cost is lower; based on the amount of real-time released data, multiple evaluations and approximations can be performed, and the real-time performance and operational simplicity are stronger.

Contents of the invention

The present invention aims to solve at least one of the problems existing in the prior art.

One of the objectives to be achieved by the present invention is to quickly realize the estimation of the earthquake influence range based on the publicly released point data of earthquake aftershocks.

In order to solve the above-mentioned technical problems, the present invention provides a method for simulating the influence range of aftershocks, the steps of which include:

Establish a coordinate system with the longitude of the aftershock point as the X axis, the latitude of the aftershock point as the Y axis, and the magnitude of the aftershock point as the Z axis;

Using the plane where the X-axis and Y-axis are located as a projection plane, transforming the coordinate system into a projected coordinate system;

Using the correlation analysis method of point pattern analysis, the relationship model of the distance between aftershock points is obtained by fitting, which is decomposed into different scale-free intervals S ₁ , S ₂ ,..., S _n , where n is the number of aftershock points and n greater than or equal to 2, where the value in the unscaled interval S _i is less than the value in the unscaled interval S _i+1 , where 1≤i≤n-1;

Perform kernel density simulation analysis of points in the scale-free interval to obtain layers L ₁ , L ₂ , ..., L _n corresponding to the scale-free intervals S ₁ , S ₂ , ..., S _n respectively;

Determine the occlusion content between the adjacent layers L _i and L _{i+1 ,} remove the corresponding occlusion content of L _{i +1} , combine Li and L i+1, and process all layers L ₁ , L ₂ , ..., L _n , output the combined layer R _i .

Further, the step also includes identifying the aftershock influence range according to the layer R _i .

Further, it is used to make a map of the area affected by the earthquake.

The beneficial effect of the present invention is to provide a method for simulating the influence range of aftershocks. The present invention can quickly evaluate the range of earthquake influence based on the publicly released point data of aftershocks. The data source is simple and the cost is lower; at the same time, the present invention can be based on The amount of data released in real time can be evaluated and approximated multiple times, and the real-time performance and ease of operation are stronger.

Description of drawings

FIG. 1 is a flow chart of a method for simulating the influence range of aftershocks according to an embodiment of the present invention.

Fig. 2 is a diagram showing the kernel density estimation of aftershocks with a single scale of 320km according to the embodiment of the present invention.

Fig. 3 is a graph showing kernel density estimation of aftershocks fused with multi-scale according to an embodiment of the present invention.

detailed description

The present invention will be described in detail below in conjunction with specific embodiments. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be regarded as isolated, and they can be combined with each other to achieve better technical effects.

As shown in Fig. 1, the present invention provides a kind of simulation method of aftershock influence range, and its step comprises:

100: Establish a coordinate system with the longitude of the aftershock point as the X axis, the latitude of the aftershock point as the Y axis, and the magnitude of the aftershock point as the Z axis;

200: Using the plane where the X-axis and the Y-axis are located as a projection plane, transform the coordinate system into a projected coordinate system;

300: Use the correlation analysis method of point pattern analysis to fit the relationship model of the distance between aftershock points, and decompose it into different scale-free intervals S1, S2, ..., Sn, where n is the number of aftershock points and n is greater than Equal to 2, where the value in the unscaled interval Si is less than the value in the unscaled interval Si+1, where 1≤i≤n-1;

400: Carry out a kernel density simulation analysis of points in the scale-free interval, and respectively obtain layers L1, L2, ..., Ln corresponding to the scale-free intervals S1, S2, ..., Sn;

500: Determine the occlusion content between the adjacent layers Li and Li+1, remove the corresponding occlusion content of Li+1, combine Li and Li+1, and process all layers L1, L2, ..., Ln in sequence , output the combined layer Ri.

600: Identify the aftershock influence range according to the layer Ri.

The method for simulating the influence range of aftershocks of the present invention can also be applied to making a map of the range of earthquake influence.

The embodiment of the present invention takes the Wenchuan area as the object of implementation:

1. In the National Earthquake Science Data Sharing Center (National Earthquake Science Data Sharing Center), download the aftershock data after the Wenchuan Earthquake, enter them into EXCEL and organize them. The data attributes include longitude (X), latitude (Y) and magnitude (Z ); in the ArcMap of ArcGIS, select AddXYdata under Toos, import the sorted EXCEL data, establish a coordinate system with the longitude of the aftershock point as the X axis, the latitude of the aftershock point as the Y axis, and the magnitude of the aftershock point as the Z axis, and perform projection transformation , and finally projected into a kilometer network; load the vector boundaries of cities and counties involved in the Wenchuan aftershock;

2. Carry out correlation dimension analysis on the aftershock points in EXCEL, the analysis formula is: C(r)=(2N _r )/N(N-1), (R<r), where R is the distance between two pairs of earthquakes r is the selected scale used to measure the distance between earthquakes, N _r is the logarithm of earthquakes whose distance R is less than r, and N is the total logarithm of selected earthquakes; for a series of selected r values, the double logarithm Curve lg[C(r)]-lg(r), on the curve, find out that section of the approximate straight line, and use least square method to fit D ₂ =lg[C(r)]/lg(r); r adopts The equidistant incremental method, the increment is 500m, and the value range is 1km-324km. The final fitting results show that the aftershock points are located at 13.5-20km, 30-43km, 66-82km, 225-236km, and 317-321.5km. The characteristic of inertial correlation in the interval is significant;

3. On the basis of spatial correlation analysis, select the median of the scale-free interval 16km, 36km, 74km, 230km, 320km as the kernel density estimation bandwidth;

4. Open the KernelDensity tool in ArcMap of ArcGIS, select the Wenchuan aftershock point data for input point, select the magnitude field of the Wenchuan aftershock point data for populationfield, first set searchradius to 320km, and output layer 320;

5. Filter out the outermost layer of 320 under the condition of not affecting the experimental results and ensuring the effect picture is beautiful. SpatialAnalyst, RasterCalculator, 320> layer minimum value, get calculation;

6. Open the ExtractbyMask tool in ArcMap of ArcGIS, select calculation for inputraster, select 320 for inputrasterorfeaturemaskdata, and output c-320;

7. SpatialAnalyst, RasterCalculator, [c-320]*[320] get calculation2, int arrangement, get calculation3, as shown in Figure 2;

8. Calculate the influence range of aftershocks when the kernel density estimation bandwidth is 230km, 74km, 36km, and 16km according to the above steps; divide the result of the minimum bandwidth of 16km into two levels, and the results of other bandwidths into one level, as shown in Figure 3.

The invention provides a method for simulating the impact range of aftershocks. The invention can quickly assess the impact range of earthquakes based on publicly released point data of aftershocks. The data source is simple and the cost is lower; at the same time, the invention can be based on real-time released data Quantity, multiple evaluations and approximations, real-time performance and easier operation.

Although some embodiments of the present invention have been given herein, those skilled in the art should understand that the embodiments herein can be changed without departing from the spirit of the present invention. The above-mentioned embodiments are only exemplary, and the embodiments herein should not be used as limitations on the scope of rights of the present invention.

Claims (3)

1. an analogy method for aftershock coverage, is characterized in that, its step comprises:

Set up with aftershock point longitude be X-axis, the aftershock point latitude coordinate system that is Z axis for Y-axis and aftershock point earthquake magnitude;

With described X-axis and face, Y-axis place for projecting plane, by described coordinate system transformation in projected coordinate system;

Utilize some pattern analysis association analysis method, matching obtain aftershock dot spacing from relation schema, be decomposed into different dimensionless interzone S ₁, S ₂..., S _n, wherein n is aftershock point number and n is more than or equal to 2, wherein dimensionless interzone S _iinterior numerical value is less than dimensionless interzone S _i+1interior numerical value, wherein 1≤i≤n-1;

In described dimensionless interzone, carry out cuclear density sunykatuib analysis a little, obtain described dimensionless interzone S respectively ₁, S ₂..., S _ncorresponding layer L ₁, L ₂..., L _n;

Judge adjacent described layer L _iwith L _i+1between block content, remove L _i+1corresponding block content after, L _iwith L _i+1combine, process All Layers L successively ₁, L ₂..., L _n, export the layer R after combination _i.

2. the analogy method of aftershock coverage according to claim 1, is characterized in that, its step also comprises according to described layer R _iidentify aftershock coverage.

3. the analogy method of aftershock coverage according to claim 1 and 2, is characterized in that, for making the map of earthquake effect scope.