基于SWMM-EFDC耦合模拟的新凤河流域水环境治理工程效应评估

科学评估水环境治理工程的环境效应,对于制定和优化河湖治理方案、推动科学治污具有重要意义。新凤河流域为北京城市副中心水安全重要保障区,水污染(黑臭)问题突出,为科学评估新凤河水环境综合治理工程效应,构建了基于暴雨洪水管理模型(SWMM)与环境流体动力学模型(EFDC)水陆一体化耦合模拟的工程环境效应评估技术方法,开展流域截污治污、湿地建设、引水补水和初期雨水调蓄工程的环境效应定量模拟评估。结果表明:影响治理工程效果的主要因子包括截污率、湿地处理标准、补水水质和初期雨水调蓄能力;综合工程及各单项工程对水质改善均有积极贡献,以水质污染物浓度平均降低率评价工程贡献结构为综合工程(69.8%)>截污(63.1%)>补水(51.7%)>湿地(50.5%)>调蓄(3.8%),以平均达标率评价工程贡献结构为综合工程(96.7%)>截污(85.2%)>湿地(32.6%)>补水(32.5%)>调蓄(0.9%),以负荷减排评价工程贡献结构为截污(512.4 t/a)>综合工程(319.3 t/a)>湿地(89.9 t/a)>调蓄(21.9 t/a)>补水(-62.6 t/a)。基于SWMM和EFDC构建的水陆一体化耦合模型在水环境治理工程效应评估中具有较好的适用性,对于城市河道的水污染控制具有一定的指导意义。

Effects assessment of water environment treatment projects based on SWMM-EFDC coupling simulation in Xinfeng River Basin

Scientific evaluation of the environmental effects of water environmental control projects is of great significance for the formulation and optimization of river and lake control schemes and the promotion of scientific pollution control. Xinfeng River Basin is an important water security area in the sub-center of Beijing, and the water pollution problem (black and smelly) was prominent. In order to scientifically evaluate the effects of water environment comprehensive control projects in the Xinfeng River, a technical method of engineering environmental effects assessment were established by coupling model of water-land integration based on SWMM and EFDC. The quantitative simulation evaluation of the environmental effects was carried out for the projects of watershed pollution interception and treatment, wetland construction, water diversion and replenishment, and initial rain regulation and storage. The results showed that the main factor affecting the effect of projects included pollution interception rate, wetland treatment standard, water quality and storage capacity of primary rain. Comprehensive projects and individual projects had made positive contributions to the improvement of water quality. In terms of average reduction rate of water quality concentration, the the project contribution was in the sequence of comprehensive projects (69.8%) > sewage interception (63.1%) > water diversion (51.7%) > wetland construction (50.5%) > initial rain storage (3.8%). In terms of average compliance rate, the sequence was comprehensive projects (96.7%) > sewage interception (85.2%) > wetland construction (32.6%) > water diversion (32.5%) > initial rain storage (0.9%). In terms of load reduction, the sequence was sewage interception (512.4 t/a) > comprehensive projects (319.3 t/a) > wetland construction (89.9 t/a) > initial rain storage (21.9 t/a)> water diversion (-62.6 t/a). The water-land integrated coupling model based on SWMM and EFDC had good applicability in the evaluation of water environment treatment engineering effect, and had certain guiding significance for water pollution control of urban rivers.