基于熵和转移矩阵分析北京地铁15号线地面沉降时空特征

首先基于PS-InSAR技术获取地铁15号线地面沉降信息,采用信息论方法计算研究区2003-2019年的熵值,然后通过转移矩阵分析地面沉降的转化规律及其与熵值变化的关系。发现2003-2020年,研究区受地质构造影响差异沉降明显,年均地面沉降速率区间为-100.17,1.19]mm/a;2016年前信息熵不断增加,地面沉降差异性较大,之后信息熵逐渐降低,沉降一致性较好;熵值大小与地面沉降的发育程度有关,沉降严重区熵值较高,沉降稳定区熵值较低;熵值增大时各沉降类型的转出率高,此时地面沉降系统不稳定,熵值减小时各沉降类型的转出率低,沉降系统较稳定。

Analysis of spatio-temporal characteristics of land subsidence on Beijing Metro Line 15 based on entropy and transition matrix

The land subsidence information of Metro Line 15 is obtained based on PS-InSAR. The entropy value of the study area from 2003 to 2019 is calculated by information theory. The transformation law of land subsidence and its relationship with the change of entropy value are analyzed through the transition matrix. It is found that from 2003 to 2020, the differential subsidence of the study area is obviously affected by the geological structure, the average annual land subsidence rate is between -100.17, 1.19] mm/a. Before 2016, the information entropy continued to increase, and the differences in land subsidence are large. After that, the information entropy gradually decreased, and the subsidence consistency is good. The value of entropy is related to the development of land subsidence, it is higher in the serious subsidence area and lower in the stable subsidence area. Entropy value increases, the subsidence type has a high transfer out rate, and the land subsidence system is unstable. Otherwise, entropy value decreases, the transfer out rate of each subsidence type is low and the subsidence system is relatively stable.