River eutrophication and CyanoHABs are severe problems that are often ignored because of high current speed and strong self‐purification. In this paper, Liangxi River, Taihu Basin, was selected as the research area. Combined with field investigation, a 2D water environment mathematical model was developed to simulate the chl‐a distribution in Liangxi River. An indicator (Transverse Distribution Center, TDC) and its normalized form (NTDC) to quantitatively represent material transverse distribution in rivers is proposed and coupled in the model. The calculation showed that TDC and NTDC had the property of random fluctuation, seasonal consistency, and water transfer dependence. The multiple regression equation with normalized data indicated that the maximum offset, average variation rate, and average reverting rate of Liangxi River chl‐a NTDC were most affected by the chl‐a dry matter flux ratio between tributaries and the mainstream, followed by flow and chl‐a concentration ratio. From the perspective of river morphology, for different river width change modes and river bending directions, when water flows into and out of these river sections, the chl‐a transverse distribution is subject to different specific effects. In addition, the position of nutrients and dissolved oxygen significantly affected the position of chl‐a growth when the N/P ratio was not very high. Conversely, a high N/P ratio may contribute to decrease of the chl‐a concentration. Proliferation with abundant nutrients may cause the settlement of chl‐a resulting in a decrease of chl‐a in the water column.

中文翻译：

---

规范性城市河流中蓝细菌的横向分布

河流富营养化和CyanoHAB是严重的问题，由于高电流速度和强大的自我净化能力，这些问题经常被忽略。本文以太湖流域两溪河为研究区域。结合野外调查，建立了二维水环境数学模型，以模拟凉溪河的车床分布。提出了一个指标（横向分配中心，TDC）及其归一化形式（NTDC），以定量表示河流中的物质横向分布，并将其耦合到模型中。计算结果表明，TDC和NTDC具有随机波动，季节性一致性和调水依赖性的性质。具有标准化数据的多元回归方程表明，最大偏移，平均变化率，支流与干流之间的干物质通量比对凉溪河chl-a NTDC的平均折返率影响最大，其次是流量和chl-a浓度比。从河流形态的角度来看，对于不同的河宽变化模式和河道弯曲方向，当水流入和流出这些河段时，chl-a的横向分布会受到不同的特定影响。另外，当氮磷比不很高时，养分和溶解氧的位置会显着影响chl-a生长的位置。相反，高的N / P比可能有助于降低chl-a浓度。营养丰富的增殖可能导致chl-a沉降，从而导致水柱中的chl-a减少。