Abstract:

The geological environmental evaluation of mine is significant for the development and utilization of mineral resources, as well as the conservation and restoration of mine environment. Proper optimal evaluation scale improves the accuracy and uniformity of the result of evaluation. This article presents a new method on determining the optimal evaluation scale based on mine geological environment. Under different scales, the evaluation area is firstly divided into grids according to its boundary, and then the scale effect performance (heterogeneity, consistency, information content and fragmentation) of each scale are quantified in order to calculate the fitting function changed with the evaluation scale. Secondly, with these fitting functions the optimal evaluation scale function is established. Finally, the range of suitable evaluation scales and the optimal scale can be obtained. This method was applied to evaluate mine geological environment in Xinluo District of Longyan City and Datian County of Sanming City,Fujian Province. The results are as following: the optimal range of suitable evaluation scales of Xinluo District and Datian County are [997.8 m, 1 194 m] and [955.5 m, 1 297.8 m], with the optimal evaluation scale 1 049.6 m and 1 182.1 m, respectively. In these scale ranges, the obtained evaluation results are basically consistent. The evaluation results of optimal evaluation scales have the best effect, thus proving the feasibility of the method. The research shows that the optimal evaluation scale function is comprehensively affected by factors such as the size of the study area, the distribution of the evaluating contents, and the geographical surroundings. This study can provide theoretical support for the determination of evaluation scale in the work of mine geological environment.

Key words: mine geological environment, evaluation unit, evaluation index, evaluation scale, scale effect