汾河入黄口水流特性与污染物扩散模拟

Simulation on Water Flow Characteristics and Pollutant Diffusion at Estuary of Fenhe River into Yellow River

为探讨交汇口污染物入河后的迁移转化规律,对汾河入黄口水流特性与污染带(化学需氧量,COD)分布进行了模拟。根据黄淤59—60断面之间实测高程值,利用插值法补充地形,并采用非结构网格划分地形。建立二维水动力水质模型,采用交替方向隐式迭代法(ADI)对水流连续性及动量守恒方程进行积分。结果表明,模型验证结果与实测资料吻合较好,用此模型对50%,75%,90%频率年汾河入黄口处进行模拟,得到了入黄口处的流速分布和污染物浓度分布结果。随着水文频率年的增大,形成的河口滩面积减小,且分别经过2.35,3.00,4.20km的距离后COD值才能达标。

Water flow characteristics and distribution of polluted belt of chemical oxygen demand（COD） at es-tuary of Fenhe River into the Yellow River were simulated to discuss its migration and transformation law. According to the measured elevation values of section 59-60, interpolation method was used to supplement the terrain data and unstructured grid was used to divide the terrain. A two-dimensional hydrodynamic and water quality model was established, and alternating direction implicit method（ADI） was adopted to give an integral of the flow＇s continuity and momentum conservation equation. The result showed a high match be- tween the simulation and the actual measurement. In addition, the velocity distribution and contaminant con- centration distribution were given by simulation of COD in 50%, 75%, 90% hydrologic year types in the es- tuary of Fenhe River into the Yellow River. Moreover, as the increase of hydrologic frequency years, the area of river mouth beael% formed was reduced, and the COD value reached the standard over the distance of 2.35, 3.00, 4.20 km.