地质界线图层的自动化生成方法

地质界线要素是地质图空间数据库的基本要素之一。地质界线图层通常是地质图空间数据库中图元最多的一个图层,其数字化和质量检验工作较为繁重。针对已有地质体面图层,而地质界线图层缺失的情况,本文提供一种快速补充地质界线图层的方法。该方法也可对原生地质界线图层进行属性数据的自动化质量检验。其主要处理环节包括：首先,基于地质体面图层,构建地质体邻接关系图,可实现对地质界线高效、准确地提取;其次,基于产状数据与断层数据,运用地层接触关系识别规则,可分别实现对基本地层接触关系和断层接触关系的自动识别;最后,针对两邻接地质体面实体多段界线间的接触关系识别结果不一致的情形,运用“平行不整合优先”原则和“长度优先”原则,进行了合理的综合判别。基于1:50 000庐山幅地质界线图层的自动化生成实验表明,本文方法可高效、快捷、准确地生成地质界线图层,既能够满足自动化补充地质界线图层的需要,又可作为检验地质界线图层属性的有效工具。

An Automatic Method for Creating the Geological Boundary Layer

It has been generally accepted that the geological boundary feature is essential and fundamental feature in the process of building the spatial database of geologic map. Owing to the largest numbers of graphic elements in geological boundary layer, its digitization and quality inspection become more onerous. The traditional method commonly starts with the drawing of geological boundary layer, then designs the geological body layer by the way of line to arc on the foundation of the geological boundary layer. According to the traditional way, we can learn that geological boundary layer and geological body layer share the same spatial data. It is consistent with the digital geological map database standards of China Geological Survey. When we have the existed geological body layer and the geological boundary layer is missing, the quick method which making the best use of the same spatial data to produce the geological boundary layer will be considered as fully remarkable and reliable. It not only puts forward an automatic method for creating the geological boundary layer, but also automatically tests the attribute data quality of the geological boundary layer. The method is implemented as a three-step process. First of all, the geological body adjacency relation graph is constructed briefly which is aimed at extracting the geological boundary efficiently and accurately based on the geological body layer. Secondly, the recognition rules of stratum contact relationship is summed up, and is applied to recognize the basic stratum contact relationship and the fault contact relationship automatically on the basis of occurrence data and fault data. Finally, according to the situation that the recognition results among the multi-segment boundaries of two adjacent stratums are not unique, principles of the "parallel unconformity first" and the "length first" are given to make a reasonable integrated judgment. This test is based on 1: 50,000 scale of Lushan geological map and created the geological boundary layer automatically. It demonstrated that this method was efficient, fast and accurate. This method has the certain advantages of a faster way to create the geological boundary layer in the process of constructing the geologic map spatial database and at the same time it is an effective tool to inspect the quality of the geological boundary layer.