基于普通克里金法的同位素测氡探火数据优化处理

Data Optimization Based on Ordinary Kriging for Radon Detection to Identify Spontaneous Combustion Areas

为优化同位素测氡探火的数据分析方法,避免目前使用的最小曲率拟合法造成的插值失真,影响火源位置的准确判定,将地质统计学中的普通克里金插值方法引入氡浓度数据的分析中,以期优化测氡探火数据的处理方法。选取古书院煤矿张岭火区同位素测氡探火数据,通过箱形图剔除原始数据中人为因素造成的孤立异常值并获得表征自燃火区测点的氡浓度区间;通过探索性数据分析和正态性检验,获得氡浓度数据的正态分布统计特征,并基于统计特征选择数据转换方法;对转换后的数据进行变异函数建模,基于该模型实现对氡浓度数据的普通克里金插值;比较普通克里金法与最小曲率法所圈定的疑似火源位置并通过钻孔验证二者的准确性。结果表明:在对张岭火区地表氡浓度的分析中,相较最小曲率法所圈定的4处疑似火区、6个疑似高温火源点,普通克里金插值方法将其减少为2处疑似火区、4个高温火源点;钻孔验证结果与普通克里金插值方法所圈定的高温火源点一致,排除最小曲率拟合法所额外圈定的2处高温火源点,证明普通克里金插值法可提高同位素测氡法对火源位置判断的准确度,对煤自燃火灾的防治具有指导作用。

In order to optimize the data analysis of radon detection,the ordinary Kriging interpolation pertaining to Geostatistics was introduced to avoid the interpolation distortion caused by the minimum curvature fitting method currently in effect.The radon detection data was collected from the Zhangling fire area of the Gushuyuan Coal Mine,the isolated outliers caused by human factors in the raw data were deleted through boxplot,and the concentration intervals that characterizes the spontaneous combustion area were obtained eventually.The statistical characteristics of the normal distribution for radon detection data were obtained through exploratory analysis and normal test and the data conversion was sorted out according to the statistical characteristics.Then,the variogram model for converted data was constructed to interpolate as the ordinary Kriging.The locations of suspected fire sources delineated by ordinary Kriging were contrasted with the locations by minimum curvature fitting method and then the accuracy was verified through drills.The results show that compared with the 4 suspected fire areas and 6 high temp fire sources delineated by the minimum curvature method,2 areas and 4 sources were fixed with the ordinary Kriging.The borehole results for high temp fire source locations are consistent with the ordinary Kriging inferences,while excluding 2 additional locations delineated by the minimum curvature fitting,which proves that the ordinary Kriging can improve the accuracy of the judgements for fire source locations and can be a guide for the prevention of coal spontaneous combustion.