铀矿井排风口尾气对周边农田土壤放射性污染的预测

On radioactive pollution forecast in soil of crop-fields near a uranium mine exhaust outlet

铀矿井尾气排风口周围土壤中放射性物质的累积性污染不容忽视,但目前处于监测和积累数据阶段。在对指数平滑法综合应用分析研究的基础上,根据某铀矿井排风口周边某一农田土壤中近10a的铀(238U)质量比监测数据建立了指数平滑预测模型,对土壤放射性铀(238U)污染进行预测,并对预测结果进行了深入分析,精度达75%以上。预测结果表明,采用指数平滑法建立土壤放射性污染预测模型是可行的,具有一定的应用价值。铀矿井排风口尾气对周边土壤的放射性累积性污染呈逐年递增趋势,迫切需要采取一些切实可行的控制措施。

This paper is inclined to bring about its own improved exponential smooth forecast model for the radioactive pollution forecast in the soil of crop-fields near a uranium mine exhaust outlet zone. As compared with the traditional exponential smooth method, the improved one of this paper involves smaller and less complicated amount of calculation and computation but enjoys higher calculation accuracy, for the whole computation process can be done by means of a computer software known as MATLAB easily. Based on the last decade＇s initial data on the U238 concentration collected and accumulated from the soil of the crop-fields in the zone, and the end results gained by bit-by-bit calculation, the authors have finally worked out that 0.4 should be the optimal smooth coefficient value and in turn established a new forecast model of U238 pollution in the soil. Then a thorough analysis has been done to its accuracy as precise as to 75.85 %. And, finally, necessary short-term on-the-spot forecasting has been made with the newly improved model. A comprehensive analysis of the gained results of exponential smooth calculation proves the new method much more feasible and practicable. In actual use, Fibonacci series method is also adopted as a reference means to opti- mally select the smooth coefficient a ; smooth initial value with recur- rence formula from the one of exponential smooth methods.