面源污染输移过程高性能数值模拟方法

高效高精度模拟面源污染输移过程，掌握面源污染的输移规律，是研究面源污染最直接有效的途径之一，也是管理和控制面源污染的有效手段。基于此，提出了一种全面耦合二维水文水动力及污染物输移过程的数值模型，采用二阶Godunov格式的有限体积法进行求解，利用GPU加速技术提高计算效率。结果表明:在理想条件下，数值解与解析解间的平均相对误差为2.5%。对不同面积和精度的城市地表面源污染和农业面源污染输移过程的模拟结果显示，二者的输移规律符合实际的物理过程，模拟总时长为7200 s，城市地表面源污染模拟结果只需186 s；农业面源污染模拟结果只需1169 s，计算效率有显著提升。综上所述，GAST模型对不同下垫面面源污染可实现高精度模拟，且模拟效率有显著提升，为今后面源污染的治理和防控提供参考。

HIGH PERFORMANCE NUMERICAL SIMULATION METHOD FOR NON-POINT SOURCE POLLUTION TRANSFER PROCESS

Efficient and high-precision simulation of the process of non-point source pollution and mastering the law of non-point source pollution is one of the most direct and effective ways to study non-point source pollution, and also an effective way to manage and control non-point source pollution. Based on this, this paper proposed a numerical model that fully coupled two-dimensional hydro-hydrodynamic and pollutant transport processes. It used the second-order Godunov format finite volume method to solve the problem, and used GPU acceleration technology to improve computing efficiency. The results showed that, under ideal conditions, the average relative error between the numerical and analytical solutions was 2.5%. The transport processes of urban surface source pollution and agricultural non-point source pollution with different areas and accuracy were simulated, and the results showed that the transport laws of the two were consistent with the actual physical process. The total simulation time was 7200 s. The simulation of urban surface source pollution took only 186 s; the simulation of agricultural non-point source pollution took 1169 s, and the calculation efficiency was significantly improved. In summary, the GAST model could not only achieve high-precision simulation of different underlying surface source pollution simulations, but also significantly improve the simulation efficiency, and provide basic support for future non-point source pollution control and prevention.