基于MODFLOW模型滹沱河傍河地下水源地保护区划分

科学合理地划分地下饮用水源地保护区，能够以最精准的范围和较低的经济成本来预防水源受到污染。基于MODFLOW模型对石家庄市滹沱河新调整的地下水源地的地下水流场进行模拟计算，采用MODPATH计算了2种不同工况下示踪粒子反向运移100和1 000 d的运移轨迹。结果表明，2种工况下示踪粒子在100 d末的平均运移距离分别为0.54和0.49 km；示踪粒子在1 000 d末的平均运移距离分别为6.1和5.6 km。此外，还分析了入渗场使用条件下地下水流场的变化。分析2种工况的计算结果表明，水源地的抽水井概化成井群时，示踪粒子反向运移的轨迹几何形状更加规则，且迁移距离相对较短。同时，考虑到入渗场补水情况，故将整个入渗场范围纳入一级保护区。

Division of protection area of groundwater source area near Hutuo River based on MODFLOW mode

The division of underground drinking water source protection areas in scientific and reasonable ways can prevent water sources from being polluted in the most precise ways and with a lower economic cost. The MODFLOW model was utilized to develop and calculate a simulation of the groundwater flow field of the Hutuo River groundwater source area in Shijiazhuang City. By utilizing the MODPATH, the 100 days and 1 000 days reverse migration trajectories of the tracer particles subjected to two different working conditions were calculated. The results were as follows: the average migration distances of the tracer particles at the end of 100 days under each of the two conditions were 0.54 km and 0.49 km; moreover, the average migration distance of each of the tracer particles at the end of 1 000 days was 6.1 km and 5.6 km. Also, the simulation considered the change of the groundwater flow field under the condition of utilizing the infiltration field. By analyzing the calculation results of these two working conditions, it was concluded that when the pumping wells inside of the water source area were generalized into the well groups, the specific trajectory geometry of the tracer particle reverse migration was more regular, and its migration distance was relatively short. At the same time, by considering the specific water supplement situation of the infiltration field, the whole infiltration field was included in the first-grade protection area as well.