基于数值模拟的嘉兴城区河网水文特征

Hydrological Characteristics of River Network in Jiaxing Urban Area Based on Numerical Simulation

基于MIKE 11河网水动力模型,利用2010年—2019年实测气象水文资料,分析了嘉兴城区大包围圈内外主要河流的入流和出流特征。结果显示:嘉兴城区主要来流河道是苏州塘和杭州塘,出流河道主要为长纤塘、嘉善塘和平湖塘;平均来流量为88.2 m^(3)/s,出流量为93.3 m^(3)/s;年均和月均来流量变化较大,最枯月的平均来流量为50.1 m^(3)/s,90%保证率枯水月的平均来流量为59.3 m^(3)/s;大包围圈内部河道的平均流量为28.3 m^(3)/s,平均出流量为19.1 m^(3)/s,这表明大量外部来水未进入大包围圈内部河道,而是通过环郊河“短路”绕过嘉兴城区,流向东北;大包围圈内部河道的最枯月平均入流量为14.5 m^(3)/s,90%保证率枯水月的平均入流量为18.3 m^(3)/s。研究结果可为嘉兴城区河网综合规划和生态治理提供科学依据。

With meteorological and hydrological measurements from 2010 to 2019,MIKE 11-based hydrodynamic model of Jiaxing urban area river network was applied in analyzing the characteristics of inflow and outflow of the main rivers of urban flood-protection encirclement.Results showed that the main inflow rivers of Jiaxing urban area were Suzhou River and Hangzhou River and the outflow rivers were Changxian River,Jiashan River and Pinghu River.Average total inflow was 88.2 m^(3)/s and the outflow was 93.3 m^(3)/s.Average annual and monthly inflow varied significantly.Average inflow in driest month was 50.1 m^(3)/s and average inflow of the 90%-guarantee rate in dry month was 59.3 m^(3)/s.Average inflow within encirclement was 28.3 m^(3)/s and average outflow was 19.1 m^(3)/s,indicating that a large amount of water from ambient rivers did not flow into encirclement,while it bypassed Jiaxing urban area through“short cut”of surrounding suburban rivers and flowed to the northwest.Average inflow in driest month within encirclement was 14.5 m^(3)/s and average inflow of the 90%-guarantee rate in dry month was 18.3 m^(3)/s.Study results might provide scientific basis for comprehensive planning and ecological management of river network of Jiaxing urban area.