综合研究断裂、地震、地壳升降等构造活动以及岩土体类型、第四系厚度等因素对区域地壳稳定的影响,定量分析研究区内地壳稳定性特征。采用GIS中的空间分析模块,构建断裂和地震对稳定性影响程度的空间分布图,解决了线性类等影响因子不易进行空间处理的问题,提高了模型的精确度。运用LM算法训练BP神经网络建立珠江三角洲区域地壳稳定性评价模型,该模型具有较强的泛化能力。结果表明:珠江三角洲稳定区面积略大于不稳定区面积,分别占总面积的54%和46%。区内不稳定区域呈带状分布,明显受区域构造断裂带控制。
After a comprehensive analysis of faults,earthquake,crust movement and rock types and even the thickness of quaternary sediments,the authors give out a prediction of stability of the crust in the Pearl River Delta.In order to increase the resolution of the model,a spatial analysis module in GIS is employed to build up the possible intensity of the influences of faults and earthquakes on crustal stability and reduce the difficulty of processing linear factors in spatial frame.LM algorithm is also applied to train BP neural network and establish the evaluation model for the crustal stability in the studied region.It is shown that the area of stable zone is slightly larger than that of the unstable one,accounting for 54% and 46% respectively,and the unstable zone is constrained in a band-shaped area,which is controlled by the observed fault zone in the studied region.