模糊逻辑法在云南中甸地区铜矿潜力预测中的应用

Porphyry Copper Mineral Prediction Using Fuzzy Logic Method in Zhongdian,Yunnan Province

模糊逻辑建模应用于矿产预测时分为两步:①变量模糊化,应用隶属函数计算变量的模糊隶属度;②模糊综合,应用模糊算子(模糊与、模糊或、模糊代数和、模糊代数积和伽马算子)对模糊化后的变量进行综合,生成最终的模糊有利度图。在介绍了模糊逻辑的基本原理和详细分析云南中甸铜成矿规律的基础上,应用ArcVie wGIS及其扩展模块ArcSDM对研究区地质、地球化学、线性构造等方面的数据进行了处理,提取了预测变量。模型应用于云南中甸普朗地区斑岩铜矿的区域成矿预测(1∶20万)结果显示,预测出的成矿潜力区包含了81%以上的已知矿点,可以用于指导进一步的大比例勘查工作。

In the application of fuzzy logic in mineral exploration,two steps are taken. Evidence map is first converted into fuzzy membership by using fuzzy membership function and then the fuzzy data sets are combined into a final favorable potential map by using fuzzy operator,such as Fuzzy AND,Fuzzy OR and Fuzzy γ. After the introduction of fuzzy logic theory and the detailed analysis of matallogenetic law of porphyry copper in Zhongdian,Yunnan Province, this paper presents the application of ArcView GIS and its extensions （Arc-SDM） in processing data and extracting forcasting variables involved with geology,geochemistry and lineaments interpreted from remote sensing data. During the fuzzy modeling in the Zhongdian area, a subjective membership function was selected to confirm membership of different variables. The choice of fuzzy operator is based on the relationship between forecasting variables and known porphyry copper deposit. The final copper potential map is generated by combining 3 ore controlling factors using gamma operator. The results show that the fuzzy set theory can integrate effectively various spatial data for mineral potential mapping and the final map delineated several favorable potential areas of mineralization for further investigation.