汶川地震前后绵阳市基础控制变化与分析

The Effect of Wenchuan Earthquake to the Topography being Covered by Mianyang Basic Control Network

本文首先分析了绵阳市基础控制网的相关精度和地震前后同一控制点坐标差的限差要求,然后根据地震前后绵阳市GPS控制网的坐标变化,得出了地震对GPS控制网覆盖范围区域的地形影响:该区域地形向东南方向分别移动的平均值为27.4cm和11.6cm;同时,越往西北方向,坐标点位差值越大,最大值为79.2cm;由于不是均匀平移,从而推断地震可能导致该区域部分地形隆起或下降。

Firstly this article analyzed the precision of Mianyang basic control network and the tolerance of the same point coordinates difference surveyed at different time, then according to the variety of Mianyang GPS control points, this article elicit the effect of Wenchuan earthquake to the topography being covered by Mianyang basic control network： the average values of this area separately moved to east and north are 27.4cm and 11.6cm; simultaneity, the more far from southeast to northwest, the larger value of point position difference is larger, the largest value is 79.2cm;because of the asymmetrical movement, this article deduced that the topography of this area be likely to arise or descend.