A two-dimensional environmental fluid dynamics code ( EFDC ) model was established for the Shuikoubaxia-Jingangtui sections in the lower reaches of the Minjiang River. The parameters of the model were calibrated using synchronously monitored hydrological and water quality data. The model was used to predict the variation of the DO concentration in the lower reaches of the Minjiang River under different conditions. The results show that, to increase the split ratio of the North Channel, to decrease the domestic sewage and livestock wastewater from Minhou County, and to enable the water quality of the Guangming River and the Baima River to reach the grade Ⅴ level could result in the increase of DO in the North Channel. In contrast, DO decreased when the discharge from the Shuikou Reservoir was reduced. In order to ensure that DO in the lower reaches of the main stream of the Minjiang River reaches the standard continuously, the following measures should be taken:increasing the split ratio of the North Channel and the discharge from the Shuikou Reservoir in the dry season, and decreasing the pollutant discharge and diverted water in the lower reaches of the Minjiang River in the dry season.%建立了闽江下游河道水口坝下—金刚腿段二维EFDC水环境数学模型,利用水文水质同步监测资料对模型进行率定,模型计算了不同条件下闽江下游河道DO浓度变化规律。结果表明：增加北港分流比,削减闽侯城镇生活、畜禽养殖污染物的排放量和使福州市区排入北港的内河(光明港、白马河)水质达到Ⅴ类水标准内,能够增加北港水体的DO,相反减小水口水库下泄流量则会导致DO降低。为确保闽江干流下游DO持续稳定达标,应采取增加北港分流比、增加枯水期水口水库下泄流量、削减区域污染物排放量、减小枯水期闽江下游调水量等措施。
展开▼
