基于ArcGIS建模器的数据处理模型在摩洛哥地球化学填图中的应用

Design of a Geochemical Data Processing Model Based on ArcGIS Model Builder and Its Application in Morocco Geochemical Mapping Project

随着我国一带一路战略部署的推进,我国在一带一路相关国家承担的地质调查任务也在逐步增加。地球化学填图由于其可靠性高、精度好、进度可控等原因,往往是国外地质调查工作的重要一环。地球化学调查工作主要环节包括野外样本采集、样本分析、数据处理及成图等。由于数据处理及成图决定了地球化学填图工作中地球化学异常的圈定及地球化学分布的判定,其模型和方法的研究越来越受到地质科学家的重视,并成为地球化学填图工作中的重要一环。设计了基于ArcGIS建模器的数据处理模型,并将其用于地球化学数据处理。该模型不仅实现了从地球化学采样数据分析到地球化学成图的自动化,而且模型可以在科研人员和生产人员之间共享。模型实现了地球化学填图工作中的以下主要功能:(1)地球化学各元素含量数据的批量插值;(2)元素的分类及异常提取;(3)用栅格数据表示的元素含量数据转换为矢量的等值线/面并平滑。该模型已成功应用于中国商务部援摩洛哥东阿特拉斯山地区1∶10万低密度地球化学填图项目,应用于包含3个工作区45种元素共7 974个地球化学样品的数据处理。成功地解决了项目有效工期短、数据分析任务重、输出图件质量要求高等问题,充分显示了模型的高效实用性,可望在未来地质调查工作中发挥巨大作用。

With the carrying out of the strategic of China One Belt One Road, the number of geological sur- vey projects undertaken by domestic institutions is growing up quickly. Geochemical mapping, due to its advancements such as high reliability, good accuracy, schedule control, is often an important part of geological survey work. The main steps in geochemical survey usually include field sample collection, sample analysis, data processing and mapping. Because data processing and mapping are greater initiative than the other two steps and can greatly affect the finally products, the method and model adapted in data processing and mapping has attracted more and more attention of geoscientist. This paper designs and implements a data processing model based on ArcGIS ModelBuilder for geochemical data processing, it can map geo- chemical data from sample analysis result automatically through a pre-designed model, moreover, it can share the model between the geological staffs and geological research scientists. The research is based on a Morocco mapping project funded by Chinese Ministry of Commerce. According to the project requirements, the model mainly solves the following main problems in the work. ①interpolation of each element from point data to raster data; ②Classification and anomaly extraction of raster data; ③Conversion of ras- ter map to vector map. The model has been successfully applied to Morocco mapping project, which is carried out by Wuhan Geological Survey Center of CGS, which is a 1 ： 100 000 low density geochemical mapping project in the East Atlas Mountains, Morocco. The project needs to deal with three working areas of 45 elements and 7 974 geochemical samples. The successful implementation of the model overcomes the difficulties of short working period, heavy task, high requirements. It would have a great application potential in the future for China＇s overseas geological survey work.