宽浅河道瞬时源源项反问题及反演精度主要影响因子分析

Inverse problem of instantaneous source in wide and shallow rivers and analysis on main influencing factors of inversion accuracy

根据宽浅河道的水动力特性和可溶性污染物在河道内的迁移转化特征,建立了宽浅河道内突发性瞬时源污染物排放位置及污染物排放量的数学反问题;采用微分进化算法,给出了反问题的数学求解方法;构造典型案例,利用瞬时源污染物浓度平面分布的理论解,对反问题求解方法进行了验证;并采用情景分析方法,进一步分析了事故应急监测点位、监测频次对污染源反演精度的影响。结果表明,反演精度依赖于监测点位的数量、监测频次等影响因子,基于一定观测数据、观测精度的污染源的数学反演,可以为瞬时源强、发生位置的确定提供技术佐证。

According to the hydrodynamic characteristics of wide and shallow rivers and the transfer characteristics of soluble pollutants in rivers,a mathematical inverse problem about location and intensity of instantaneous pollution source in wide and shallow rivers is established. The solving method of this problem is given using differential evolution algorithm. A typical case is set out and the solving method is verified using the theoretical solution of concentration plane distribution of instantaneous pollution source. Based on the scene analysis method,further analysis is made to analyses the influence of monitoring sites and monitoring frequency on inversion accuracy of the pollution source. The results indicate that： the inversion accuracy depends on several influencing factors including the number of monitoring sites and monitoring frequency. The mathematical inverse problem of pollution source based on certain monitoring data and monitoring accuracy can provide technical support on determining the intensity and location of instantaneous pollution source.